An electronic keyboard instrument

Abstract

The present invention provides an electronic keyboard musical instrument, relating to the field of electronic technology. The electronic keyboard musical instrument comprises keys, carbon film contacts beneath the keys, and a sound source chip on a mainboard. The left and right hands or each finger of a person playing the keyboard musical instrument respectively correspond to one or a group of relatively independent sound source chips. A switching circuit is provided between the conductor keys and the relatively independent carbon film contacts beneath the keys and the sound source chips corresponding to the left and right hands or each finger. Each switching circuit comprises a direct current power supply and a photocoupler group whose number matches the number of keys; or comprises a single-chip microcomputer circuit and a photocoupler group whose number matches the number of keys. The switching circuit is connected to a wire output end of a conductor glove via a control line. When two hands or multiple fingers wearing the conductor gloves press keys simultaneously, the photocoupler group in the switching circuit connected to the corresponding sound source chip is activated, further switching on the pins corresponding to the relevant sound source chip, thereby playing stereo sounds with different sound sources.

Description

Technical Field

[0001] The present invention relates to the field of electronic technology, and in particular to an electronic keyboard musical instrument. Background Art

[0002] The keys of traditional electronic keyboards and electric pianos have conductive rubber and a printed circuit board underneath, with carbon film contacts arranged on the printed circuit board. In a dual-force sensing key structure, the carbon film contacts under each key are usually divided into four parts. We call the two interconnected contacts common carbon film contacts, also known as the C-zone carbon film contacts, and the other two contacts are called non-common carbon film contacts, also known as the A-zone carbon film contacts and the B-zone carbon film contacts. In a triple-force sensing key structure, the carbon film contacts under each key are usually divided into six parts. We call the three interconnected contacts common carbon film contacts, also known as the D-zone carbon film contacts, and the other three contacts are called non-common carbon film contacts, also known as the A-zone carbon film contacts, the B-zone carbon film contacts, and the C-zone carbon film contacts.

[0003] Modern electronic keyboards typically use PCM sampling as their sound source. Sampling involves recording the sound of an instrument, digitizing it, and storing it in ROM or Flash memory. Then, when a key is pressed, the CPU or DSP chip plays back the sound. Chips that can store and play back sampled sound sources are called sound source chips.

[0004] In traditional electronic keyboard instruments, for example, the carbon film contacts in areas A, C, and B under each key are not independent of the carbon film contacts in the same areas under other keys on the printed circuit board. Instead, they are matrixed and connected to the corresponding pins on the sound source chip on the motherboard via rows of wires. When a key is pressed, the conductive rubber sequentially connects the carbon film contacts in areas A and C, and then the carbon film contacts in areas B and C. This, in turn, also connects the corresponding pins on the sound source chip, triggering the circuitry within the sound source chip of the electronic keyboard or electric piano to produce sound, thus fulfilling the function of a velocity-sensitive key press and also acting as a switch.

[0005] When playing with both hands on the keyboard of a traditional electronic organ or electric piano, the sound sources of the left and right hands cannot be separated. No matter how many keys are played at the same time, the sounds will be mixed together, and the sense of direction and layering will not be reflected. In addition, when using dual-timbre and multi-timbre modes, the sound source of each tone is not independent. Summary of the Invention

[0006] On the keyboard or electric piano, we hope that the sound sources of the content played by both hands can be independent of each other. When the left and right hands touch the keys at the same time, the corresponding sound sources will sound at the same time; we also hope that different fingers touching the keys will control different corresponding sound source chips, and when multiple keys are pressed at the same time, multiple relatively independent sound source chips will work at the same time.

[0007] In order to solve the above technical deficiencies of conventional electronic keyboard instruments, the present invention provides an electronic keyboard instrument with stereo function:

[0008] An electronic keyboard musical instrument comprises keys, carbon film contacts under the keys and a sound source chip on a mainboard;

[0009] The left and right hands or each finger of the keyboard player respectively correspond to one or a group of relatively independent sound source chips;

[0010] Two or more of the sound source chips share a layer of keys and carbon film contacts under the keys, the keys are conductor keys, and the carbon film contacts are relatively independent;

[0011] A switch circuit is provided between the conductor keys and the relatively independent carbon film contacts below them and the sound source chips corresponding to the left and right hands or each finger respectively;

[0012] The switch circuit includes a DC power supply and a number of optocoupler groups that matches the number of piano keys, or includes a single-chip microcomputer circuit and a number of optocoupler groups that matches the number of piano keys;

[0013] Playing electronic keyboard instruments with conductor keys requires the use of conductor gloves;

[0014] The switch circuit is connected to the wire input terminal on the conductor glove via a control wire;

[0015] By pressing any of the conductor keys with the left or right hand or a finger wearing the conductor glove, the corresponding optocoupler group in the related switch circuit can be controlled, and further the corresponding pin in the related sound source chip can be controlled.

[0016] In mid- to high-end electronic keyboard instruments, the carbon film contacts, after being matrixed, are not directly connected to the sound source chip. Instead, they are connected to the sound source chip via the key control CPU. Different electronic keyboard instruments have different sound source chips and different pin connection relationships. The key control CPU and sound source chip are state-of-the-art and will not be discussed in detail here.

[0017] The sound source chip mentioned in this article may include a key control CPU at the front end. The sentence described in the article as being connected to the corresponding pins of the relevant sound source chip can be interpreted as being connected to the corresponding pins of the relevant key control CPU.

[0018] In the above technical solution, the carbon film contact under the same key simultaneously controls the corresponding optocoupler groups in two or more switch circuits. When the left or right hand or each finger presses different keys at the same time, it is required that no current loop is allowed to form between different optocoupler groups under the same key.

[0019] The non-common carbon film contacts under the keys are connected to the input ends of the optocouplers in the optocoupler group, and the output ends of each optocoupler in the optocoupler group are connected to the sound source chip. When the optocoupler is activated, it can simultaneously connect the two corresponding pins in the relevant sound source chip. This method can achieve stereo sound superposition.

[0020] The carbon film contacts under the keys are divided into different zones, and each zone is connected to one end of the output of the corresponding optocoupler in the optocoupler group. The other end of the optocoupler output is connected to the sound source chip. When the optocoupler is started, the connection between the carbon film contact and the sound source chip will be connected. This method cannot achieve stereo sound superposition.

[0021] We have designed the following switching circuits for use in various electronic keyboard instruments to ensure that when two or more switching circuits operate simultaneously, no current loops are formed between them.

[0022] In the switching circuit that constitutes a stereo electronic keyboard instrument, we call the DC power switching circuit that requires the use of a conductor keyboard and a conductor glove a B-type switching circuit, and the combination of two B-type switching circuits is called a BB combination switching circuit.

[0023] The BB combination switch circuit includes a left channel switch circuit and a right channel switch circuit; the left channel switch circuit and the right channel switch circuit both include independent DC power supplies and optocoupler groups that are the same in number as the piano keys; the current directions of the left channel switch circuit and the right channel switch circuit are opposite.

[0024] In the BB combination switch circuit, a protection circuit is designed on the switch circuit control line connecting the left and right channel conductor gloves. Whenever the two control lines meet, the protection circuit is activated, causing at least one switch circuit control line to enter an interrupted state. This can prevent the adverse effects caused by the two switch circuit control lines connected to the left and right channel conductor gloves accidentally touching each other.

[0025] We call the BB combination switch circuit that can realize the function of sound superposition stereo the new BB combination switch circuit. We call the BB combination switch circuit that cannot realize the function of sound superposition stereo the old BB combination switch circuit.

[0026] In the switching circuit that constitutes a stereo electronic keyboard instrument, the single-chip microcomputer circuit is combined with the optocoupler group. We call the single-chip microcomputer circuit that requires the application of a conductor keyboard and a conductor glove a C-type switching circuit, and the combination of two or more C-type switching circuits is called a CC combination switching circuit.

[0027] In a two-channel switch circuit corresponding to the left and right hands playing a keyboard instrument, or in a multi-channel switch circuit corresponding to multiple fingers playing a keyboard instrument, each switch circuit includes a single-chip microcomputer circuit and a photocoupler group that matches the number of keys;

[0028] Between two or more single-chip microcomputer circuits, the input pin wires at the same position are combined together and connected to the corresponding conductor keys in sequence;

[0029] In each of the switch circuits, the optocoupler group corresponding to the piano key is arranged between the output terminal corresponding to the single chip circuit and the VCC or GND pin;

[0030] Each of the single chip microcomputer circuits leads out a high and low level control line as a control line of the switch circuit, which is connected to the wire input end on the corresponding conductor glove.

[0031] We call the CC combination switch circuit that can realize the sound superposition stereo function the new CC combination switch circuit. We call the CC combination switch circuit that cannot realize the sound superposition stereo function the old CC combination switch circuit.

[0032] In the switching circuit that makes up a stereo electronic keyboard instrument, a DC power supply is combined with an optocoupler group. One end of the input terminals of all optocouplers in the optocoupler group is connected to an electrode of the DC power supply, and the other end of the input terminal of each optocoupler in the optocoupler group is connected one-to-one to different partitions of relatively independent non-common carbon film contacts under the keys. The common carbon film contacts are connected to the other end of the DC power supply. We call this switching circuit that does not require a conductor keyboard or a conductor glove a type A switching circuit, and the combination of two type A switching circuits is called an AA combination switching circuit.

[0033] An electronic keyboard musical instrument comprises keys, carbon film contacts under the keys and a sound source chip on a mainboard;

[0034] The left and right hands playing the keyboard instrument correspond to one or a group of relatively independent sound source chips respectively;

[0035] The keys are divided into a left keyboard area and a right keyboard area;

[0036] A left channel switching circuit is provided between the carbon film contacts under the keys in the left keyboard area and the sound source chip corresponding to the left hand;

[0037] A right channel switching circuit is set between the carbon film contacts under the keys in the right keyboard area and the sound source chip corresponding to the right hand;

[0038] The left channel switching circuit and the right channel switching circuit include a common DC power supply and a photocoupler group having the same number as the corresponding partitioned keys;

[0039] When the left or right hand presses the piano keys, the conductive rubber covers the carbon film contacts, which can control the corresponding optocoupler group in the relevant switch circuit, and further control the corresponding pins in the relevant sound source chip.

[0040] The AA combination switch circuit eliminates the need for conductor keys, and electronic keyboard instruments using the AA combination switch circuit also do not require the use of conductor gloves. The AA combination switch circuit includes a fixed AA combination partition structure and an adjustable AA combination partition structure. The AA combination switch circuit is characterized by its ability to achieve stereo sound with superimposed tones.

[0041] In the switch circuit that constitutes a stereo electronic keyboard instrument, a combination of an A-type circuit and a B-type circuit, in which the A-type circuit can be controlled by the B-type circuit, or the B-type circuit can be controlled by the A-type circuit, is called an AB combination switch circuit.

[0042] The AB combination switch circuit includes a left channel switch circuit and a right channel switch circuit;

[0043] The left channel switching circuit and the right channel switching circuit include a DC power supply and a number of optocoupler groups that matches the number of piano keys, or include a single-chip microcomputer circuit and a number of optocoupler groups that matches the number of piano keys;

[0044] Wherein, each of the optocoupler groups in the right channel switch circuit is controlled by a corresponding optocoupler normally closed solid-state relay, and the corresponding optocoupler normally closed solid-state relay is controlled by the left channel switch circuit;

[0045] When the left hand wearing the conductive glove presses the piano key, the corresponding optocoupler group in the left channel switch circuit will be activated, and at the same time, the corresponding optocoupler normally closed solid-state relay will be used to close the corresponding optocoupler group in the right channel switch circuit under the same key.

[0046] We call the AB combination switch circuit that can realize the function of sound superposition stereophonic sound the new AB combination switch circuit. We call the AB combination switch circuit that cannot realize the function of sound superposition stereophonic sound the old AB combination switch circuit.

[0047] In the switching circuit that constitutes a stereo electronic keyboard instrument, a combination of an A-type circuit and a C-type circuit, in which the A-type circuit can be controlled by the C-type circuit, or the C-type circuit can be controlled by the A-type circuit, is called an AC combination circuit.

[0048] The AC combination switch circuit includes a left channel switch circuit and a right channel switch circuit, each of which includes a single-chip microcomputer circuit and a number of optocoupler groups that matches the number of piano keys; wherein the right channel switch circuit is an A-type circuit, and each optocoupler group in the right channel switch circuit is controlled by an optocoupler normally closed solid-state relay, which is in turn controlled by the left channel switch circuit;

[0049] When the left hand wearing the conductive glove presses the piano key, the corresponding optocoupler group in the left channel switch circuit will be activated, and at the same time, the corresponding optocoupler normally closed solid-state relay will be used to close the corresponding optocoupler group in the right channel switch circuit under the same key.

[0050] We call the AC combination switch circuit that can realize the sound superposition stereo function the new AC combination switch circuit. We call the AC combination switch circuit that cannot realize the sound superposition stereo function the old AC combination switch circuit.

[0051] In the AB and AC combination switch circuits, relatively independent A and B contacts are arranged on the keys. The B contacts are combined and connected to the control line in the switch circuit, while the A contacts function as the original conductor keyboard. The relatively independent A and B contacts combine to function as a contact switch on the keyboard, enabling wireless applications of the conductor gloves used for playing keyboard instruments.

[0052] The beneficial effects produced by the above technical solution are as follows: in a two-channel or multi-channel switching circuit, the left and right hands or each finger correspond to one or a group of sound source chips respectively, and a conductive keyboard and conductive gloves are used, as well as a switching circuit between relatively independent carbon film contacts and the sound source chips arranged under the keyboard. On a single-layer keyboard, when two hands or multiple fingers wearing conductive gloves press the keys at the same time, the optocoupler group in the switching circuit connected to the corresponding sound source chip will be activated, and the corresponding pins of the relevant sound source chips will be further turned on, thereby playing stereo sounds with different sound sources. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings to be used in the description of the embodiments. The drawings of the present invention described below are only partial drawings of the embodiments. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.

[0054] Figure 1 This is a schematic diagram of the structure of a new BB combination switch circuit for an electronic keyboard instrument provided by an embodiment of the present invention;

[0055] Figure 2 This is a schematic diagram of the structure of the old BB combination switch circuit of the electronic keyboard musical instrument provided by an embodiment of the present invention;

[0056] Figure 3 This is a schematic diagram of the structure of a new CC combination switch circuit for an electronic keyboard instrument provided by an embodiment of the present invention;

[0057] Figure 4 This is a schematic diagram of the CC combination switch circuit structure of an electronic keyboard musical instrument provided by an embodiment of the present invention;

[0058] Figure 5 This is a schematic diagram of the keyboard partition fixing structure of the AA combination switch circuit of the electronic keyboard musical instrument provided by an embodiment of the present invention;

[0059] Figure 6 This is a schematic diagram of the keyboard partition adjustable structure of the AA combination switch circuit of the electronic keyboard musical instrument provided by an embodiment of the present invention;

[0060] Figure 7 This is a schematic diagram of the structure of a new AB combination switch circuit of a basic version of an electronic keyboard instrument provided by an embodiment of the present invention;

[0061] Figure 8 This is a schematic diagram of the AB combination switch circuit structure of the basic version of the electronic keyboard instrument provided by an embodiment of the present invention;

[0062] Figure 9 This is a schematic diagram of the structure of the new AB combination switch circuit of the upgraded version of the electronic keyboard instrument provided by an embodiment of the present invention;

[0063] Figure 10 This is a schematic diagram of the structure of the old AB combination switch circuit of the upgraded version of the electronic keyboard musical instrument provided by an embodiment of the present invention;

[0064] Figure 11 This is a schematic diagram of the structure of a new AC combination switch circuit of the supplementary version of the electronic keyboard musical instrument provided by an embodiment of the present invention;

[0065] Figure 12 This is a schematic diagram of the structure of an old AC combination switch circuit of a supplementary version of an electronic keyboard instrument provided by an embodiment of the present invention;

[0066] Figure 13 2. It is a schematic diagram of a stereo dual-timbre structure of an electronic keyboard musical instrument provided by an embodiment of the present invention;

[0067] Figure 14 This is a schematic diagram of the connection between the optocouplers in the optocoupler group provided by an embodiment of the present invention and the corresponding pins of the related audio source chip.

[0068] Figure 15 This is a schematic diagram of the connection between the optocouplers in the optocoupler group provided by an embodiment of the present invention and the corresponding pins of the related audio source chip.

[0069] Figure 16This is a schematic diagram of the connection between the carbon film contacts under the keys of a traditional electronic keyboard instrument and the corresponding pins of a sound source chip provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0070] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0071] In this application, the terms "comprises," "comprising," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not preclude the presence of additional identical elements in the process, method, article, or apparatus that includes the element.

[0072] Specific implementation 1: New BB combination switch circuit

[0073] In the left-channel switching circuit, the positive input terminals of all the optocouplers in each optocoupler group are combined and connected to the positive wire of the left-channel DC power supply; the negative input terminals of each optocoupler in each optocoupler group are connected one-to-one to different partitions of relatively independent non-common carbon film contacts under the corresponding conductor key; the common carbon film contacts are connected to the corresponding conductor key; the negative wire of the left-channel DC power supply serves as the control line of the switching circuit and is connected to the wire input terminal on the left-channel conductor glove;

[0074] In the right channel switching circuit, the negative input terminals of all the optocouplers in each optocoupler group are combined and connected to the negative wire of the right channel DC power supply; the positive input terminal of each optocoupler in each optocoupler group is connected one-to-one to different partitions of relatively independent non-common carbon film contacts under the corresponding conductor key; the common carbon film contacts are connected to the corresponding conductor keys; the positive wire of the right channel DC power supply serves as the control line of the switching circuit and is connected to the wire input terminal on the right channel conductor glove.

[0075] In each switching circuit, the positive and negative output pins of each optocoupler in the optocoupler group are respectively combined with the same output pins of the optocouplers at the same position in other optocoupler groups in the same circuit, using the matrix key rules of traditional electronic keyboard instruments, and then connected to the corresponding pins of the relevant sound source chip.

[0076] Working principle of the new BB combination switch circuit:

[0077] In the left and right channel switching circuits, when the left hand wearing the conductive glove presses a key, the optocoupler in the optocoupler group between the left channel DC power supply and the corresponding carbon film contact under the conductive keyboard forms a current loop and is activated. When the right hand wearing the conductive glove presses a key, the optocoupler in the optocoupler group between the right channel DC power supply and the corresponding carbon film contact under the conductive keyboard forms a current loop and is activated.

[0078] When the fingers of both hands press different keys at the same time, the two switching circuits work at the same time, which can simultaneously start the optocouplers in the corresponding optocoupler groups in the two circuits. The corresponding pins of the relevant sound source chip connected at both ends of each optocoupler output end through wires will be turned on, and two-channel stereo sound can be played.

[0079] The current directions of the two switching circuits are opposite. When two hands wearing conductive gloves touch the keys at the same time, no current loop will be formed between the left and right channel optocoupler groups under the same key through the finger wires.

[0080] Figure 1 This is a schematic diagram of the structure of the new BB combination switch circuit of the electronic keyboard instrument

[0081] In the figure, BB101 is the conductor keyboard. BB102 is the carbon film contact in Area A. BB103 is the carbon film contact in Area C. BB104 is the carbon film contact in Area B. BB105 is the left channel conductor glove. BB106 is the wire input terminal on the conductor glove. BB107 is the left channel DC power supply. BB108 is the first optocoupler for the left channel. BB109 is the second optocoupler for the left channel. BB110 is the left channel audio source chip. BB111 is the pin in Area A of the left channel audio source chip. BB112 is the pin in Area C of the left channel audio source chip. BB113 is the pin in Area B of the left channel audio source chip. BB114 is the right channel conductor glove. BB115 is the finger wire on the conductor glove. BB116 is the right channel DC power supply. BB117 is the first optocoupler for the right channel. BB118 is the second optocoupler for the right channel. BB119 is the right channel audio source chip. BB120 is the right channel audio source chip's Area A pin. BB121 is the right channel audio source chip's Area C pin. BB122 is the right channel audio source chip's Area B pin.

[0082] In the implementation of the new BB combination switch circuit:

[0083] (1) Two or two groups of relatively independent sound source chips are used, corresponding to the left and right hands playing the keyboard instrument respectively. The two or two groups of relatively independent sound source chips share a layer of conductor keys BB101 and carbon film contacts under the keys.

[0084] (2) Taking a dual-velocity electronic keyboard instrument as an example, the carbon film contacts under the keys are divided into relatively independent carbon film contacts in area A (BB102), relatively independent carbon film contacts in area C (BB103), and relatively independent carbon film contacts in area B (BB104). The carbon film contacts in area C are common carbon film contacts, while the carbon film contacts in areas A and B are non-common carbon film contacts.

[0085] (3) Two sets of switch circuits corresponding to the left and right channels are set between the carbon film contacts and the two sound source chips. Each set of switch circuits includes a DC power supply and an optocoupler group that is the same as the number of piano keys.

[0086] (4) In the left and right channel switching circuits, each optocoupler group in each switching circuit includes a first optocoupler corresponding to the carbon film contacts in area A and area C below the keyboard and a second optocoupler corresponding to the carbon film contacts in area B and area C below the keyboard.

[0087] (5) In the left channel switch circuit, the positive input terminal of the first optocoupler BB108 and the positive input terminal of the second optocoupler BB109 are combined and connected to the positive wire of the DC power supply BB107. The negative input terminal of the first optocoupler BB108 is connected to the carbon film contact BB102 in area A under the corresponding key, and the negative input terminal of the second optocoupler BB109 is connected to the carbon film contact BB104 in area B under the corresponding key.

[0088] (6) In the right channel switch circuit, the negative input terminal of the first optocoupler BB117 and the negative input terminal of the second optocoupler BB118 are combined and connected to the negative wire of the DC power supply BB116. The positive input terminal of the first optocoupler BB117 is connected to the carbon film contact BB102 in area A under the corresponding key, and the positive input terminal of the second optocoupler BB118 is connected to the carbon film contact BB104 in area B under the corresponding key.

[0089] (7) In the left channel optocoupler group, the positive output pin of the first optocoupler BB108 and the positive output pin of the first optocoupler BB108 in other optocoupler groups are matrix-synthesized according to the matrix key-pressing rule of a traditional electronic keyboard instrument, and then connected to the corresponding pin in the A-zone pin BB111 of the left channel sound source chip BB110; the negative output pin of the first optocoupler BB108 and the negative output pin of the first optocoupler BB108 in other optocoupler groups are matrix-synthesized according to the matrix key-pressing rule of a traditional electronic keyboard instrument, and then connected to the corresponding pin in the C-zone pin BB112 of the left channel sound source chip BB110;

[0090] (8) In the left channel optocoupler group, the positive output pin of the second optocoupler BB109 and the positive output pin of the second optocoupler BB109 in other optocoupler groups are matrix-synthesized according to the matrix key rules of a traditional electronic keyboard instrument, and then connected to the corresponding pin in the B area pin BB113 of the left channel sound source chip BB110; the negative output pin of the second optocoupler BB109 and the negative output pin of the second optocoupler BB109 in other optocoupler groups are matrix-synthesized according to the matrix key rules of a traditional electronic keyboard instrument, and then connected to the corresponding pin in the C area pin BB112 of the left channel sound source chip BB110.

[0091] (9) In the right channel optocoupler group, the positive output pin of the first optocoupler BB117 and the positive output pin of the first optocoupler BB117 in other optocoupler groups are matrix-synthesized according to the matrix key-pressing rule of a traditional electronic keyboard instrument, and then connected to the corresponding pin in the A-zone pin BB120 of the right channel sound source chip BB119; the negative output pin of the first optocoupler BB117 and the negative output pin of the first optocoupler BB117 in other optocoupler groups are matrix-synthesized according to the matrix key-pressing rule of a traditional electronic keyboard instrument, and then connected to the corresponding pin in the C-zone pin BB121 of the right channel sound source chip BB119;

[0092] (10) In the right channel optocoupler group, the positive output pin of the second optocoupler BB118 and the positive output pin of the second optocoupler BB118 in other optocoupler groups are matrix-synthesized according to the matrix key rules of traditional electronic keyboard instruments, and then connected to the corresponding pin in the B area pin BB122 of the right channel sound source chip BB119; the negative output pin of the second optocoupler BB118 and the negative output pin of the second optocoupler BB118 in other optocoupler groups are matrix-synthesized according to the matrix key rules of traditional electronic keyboard instruments, and then connected to the corresponding pin in the C area pin BB121 of the right channel sound source chip BB119.

[0093] (11) The conductor keyboard BB101 is connected to the corresponding C-zone carbon film contact BB103.

[0094] (12) The wire input terminal BB106 on the left-hand conductor glove BB105 is connected to the negative electrode of the left-channel DC power supply BB107, and the wire input terminal BB115 on the right-hand conductor glove BB114 is connected to the positive electrode of the right-channel DC power supply BB116.

[0095] Specific implementation 2: Old BB combination switch circuit

[0096] In the left channel switching circuit, the positive input terminals of all the optocouplers in the optocoupler group are combined together and connected to the positive wire of the left channel DC power supply; the negative input terminals of all the optocouplers in the optocoupler group are combined together and connected to the corresponding conductor keys; the negative wire of the left channel DC power supply serves as the control line of the switching circuit and is connected to the wire input terminal on the left channel conductor glove;

[0097] In the right channel switching circuit, the negative input terminals of all the optocouplers in the optocoupler group are combined together and connected to the negative wire of the right channel DC power supply; the positive input terminals of all the optocouplers in the optocoupler group are combined together and connected to the corresponding conductor keys; the positive wire of the right channel DC power supply serves as the control line of the switching circuit and is connected to the wire input terminal on the right channel conductor glove.

[0098] In each switching circuit, one pin of each optocoupler output end in the optocoupler group is connected to the corresponding carbon film contact end wire; another pin of each optocoupler output end in the optocoupler group is matrix synthesized with the same output end pin of the optocoupler at the same position in other optocoupler groups in the same circuit according to the matrix key rules of traditional electronic keyboard instruments, and then connected to the corresponding pin of the relevant sound source chip.

[0099] In the new and old BB combination switch circuits of an electronic keyboard instrument, a protection circuit is designed on the control lines of the left and right channel switch circuits. The protection circuit includes an optocoupler normally closed solid-state relay. The positive pole of the input terminal of the optocoupler normally closed solid-state relay is connected to the positive pole wire of the DC power supply of the right channel switch circuit. The negative pole wire of the DC power supply of the right channel switch circuit serves as the control line of the right channel switch circuit. The negative pole of the input terminal and the negative pole of the output terminal of the optocoupler normally closed solid-state relay are combined to serve as the control line of the left channel switch circuit. The positive pole wire of the DC power supply of the left channel switch circuit is connected to the positive pole of the output terminal of the optocoupler normally closed solid-state relay.

[0100] Alternatively, the negative pole of the input terminal of the optocoupler normally closed solid-state relay is connected to the negative pole wire of the DC power supply of the left channel switching circuit, the positive pole wire of the DC power supply of the left channel switching circuit serves as the control line of the left channel switching circuit, the positive pole of the input terminal and the positive pole of the output terminal of the optocoupler normally closed solid-state relay are combined together as the control line of the right channel switching circuit, and the negative pole wire of the DC power supply of the right channel switching circuit is connected to the negative pole of the output terminal of the optocoupler normally closed solid-state relay.

[0101] In this way, when the two switch circuit control lines are in contact, the optocoupler normally closed solid-state relay will be powered on and turned on, and the output end of the optocoupler normally closed solid-state relay will disconnect one of the switch circuit control lines connected to the DC power supply, so that a current loop cannot be formed between the two switch circuit control lines.

[0102] Working principle of the old BB combination switch circuit:

[0103] In the left and right channel switching circuits, when the left hand wearing the conductive glove presses a key, the optocoupler in the optocoupler group between the left channel DC power supply and the corresponding conductive keyboard forms a current loop and is activated. When the right hand wearing the conductive glove presses a key, the optocoupler in the optocoupler group between the right channel DC power supply and the corresponding conductive keyboard forms a current loop and is activated.

[0104] By pressing different keys with the fingers of both hands at the same time, the optocouplers in the corresponding optocoupler groups in the two switch circuits can be activated at the same time. The connection between the carbon film contacts at the output end of the optocoupler and the corresponding pins of the relevant sound source chip is further connected, and stereo sounds with different sound sources will be played.

[0105] The current directions of the two switching circuits are opposite. When two hands wearing conductive gloves touch the keys at the same time, no current loop will be formed between the left and right channel optocoupler groups under the same key through the finger wires.

[0106] Figure 2 This is a schematic diagram of the structure of the old BB combination switch circuit of the electronic keyboard instrument

[0107] In the figure, BB201 is the conductor keyboard. BB202 is the carbon film contact in Area A. BB203 is the carbon film contact in Area C. BB204 is the carbon film contact in Area B. BB205 is the left channel conductor glove. BB206 is the wire input terminal on the conductor glove. BB207 is the left channel DC power supply. BB208 is the first optocoupler for the left channel. BB209 is the second optocoupler for the left channel. BB210 is the third optocoupler for the left channel. BB211 is the left channel audio source chip. BB212 is the pin in Area A of the left channel audio source chip. BB213 is the pin in Area C of the left channel audio source chip. BB214 is the pin in Area B of the left channel audio source chip. BB215 is the right channel conductor glove. BB216 is the wire input terminal on the conductor glove. BB217 is the right channel DC power supply. BB218 is the first optocoupler for the right channel. BB219 is the second optocoupler for the right channel. BB220 is the third optocoupler for the right channel. BB221 is the right channel audio source chip. BB222 is the pin in Area A of the right channel audio source chip. BB223 is the pin in Area C of the right channel audio source chip. BB224 is the pin in Area B of the right channel audio source chip.

[0108] In the implementation of the old BB combination switch circuit:

[0109] (1) Two or two groups of relatively independent sound source chips are used, corresponding to the left and right hands playing the keyboard instrument respectively, and the two or two groups of relatively independent sound source chips share a layer of conductor keys BB201 and carbon film contacts under the keys.

[0110] (2) Taking a dual-velocity electronic keyboard instrument as an example, the carbon film contacts under the keys are divided into relatively independent carbon film contacts in area A (BB202), relatively independent carbon film contacts in area C (BB203), and relatively independent carbon film contacts in area B (BB204). The carbon film contacts in area C are common carbon film contacts, while the carbon film contacts in areas A and B are non-common carbon film contacts.

[0111] (3) Two sets of switch circuits corresponding to the left and right channels are set between the carbon film contacts and the two sound source chips. Each set of switch circuits includes a relatively independent DC power supply and an optocoupler group that is consistent with the number of piano keys.

[0112] (4) In the left and right channel switching circuits, each optocoupler group in each switching circuit includes a first optocoupler corresponding to the carbon film contact in area A below the keyboard, a second optocoupler corresponding to the carbon film contact in area C below the keyboard, and a third optocoupler corresponding to the carbon film contact in area B below the keyboard.

[0113] (5) In the left channel switching circuit, the positive input terminals of all optocouplers in each optocoupler group are connected to the positive conductor of the DC power supply BB207, and the negative input terminals of all optocouplers in each optocoupler group are connected to the corresponding conductor key BB201.

[0114] (6) In the right channel switch circuit, the negative poles of the input terminals of all the optocouplers in each optocoupler group are connected to the negative wire of the DC power supply BB217, and the positive poles of the input terminals of all the optocouplers in each optocoupler group are connected to the corresponding conductor key BB201.

[0115] (7) In the left and right channel switching circuits, the negative output terminal of the first optocoupler in all optocoupler groups is connected to the carbon film contact BB202 in area A under the corresponding key, the positive output terminal of the second optocoupler is connected to the carbon film contact BB203 in area C under the corresponding key, and the negative output terminal of the third optocoupler is connected to the carbon film contact BB204 in area B under the corresponding key.

[0116] (8) In each optocoupler group of the left channel switch circuit, the positive output terminal of the first optocoupler BB208 is combined with the positive output terminals of the first optocouplers BB208 in other optocoupler groups according to the matrix keying rule of a traditional electronic keyboard instrument, and then connected to the corresponding pin in the A area pin BB212 of the left channel sound source chip BB211;

[0117] The negative output pin of the second optocoupler BB209 and the negative output pins of the second optocouplers BB209 in other optocoupler groups are matrix-synthesized using the matrix keying rules of a traditional electronic keyboard instrument, and then connected to the corresponding pin in the C-zone pin BB213 of the left channel sound source chip BB211;

[0118] The positive output terminal of the third optocoupler BB210 and the positive output terminal pins of the third optocouplers BB210 in other optocoupler groups are matrix synthesized according to the matrix key rules of traditional electronic keyboard instruments, and then connected to the corresponding pins in the B area pins BB214 in the left channel sound source chip BB211.

[0119] (9) In each optocoupler group of the right channel switch circuit, the positive output terminal of the first optocoupler BB218 is combined with the positive output terminals of the first optocouplers BB218 in other optocoupler groups according to the matrix keying rule of a traditional electronic keyboard instrument, and then connected to the corresponding pin in the A area pin BB222 of the right channel sound source chip BB221;

[0120] The negative output pin of the second optocoupler BB219 and the negative output pins of the second optocouplers BB219 in other optocoupler groups are matrix-synthesized using the matrix keying rules of a traditional electronic keyboard instrument, and then connected to the corresponding pin in the C-zone pin BB223 of the right channel sound source chip BB221;

[0121] The positive output terminal of the third optocoupler BB220 and the positive output terminal pins of the third optocouplers BB220 in other optocoupler groups are matrix synthesized according to the matrix key rules of traditional electronic keyboard instruments, and then connected to the corresponding pins in the B area pins BB224 in the right channel sound source chip BB221.

[0122] (10) The wire input terminal BB206 on the left-hand conductor glove BB205 is connected to the negative electrode of the left-channel DC power supply BB207, and the wire input terminal BB216 on the right-hand conductor glove BB215 is connected to the positive electrode of the right-channel DC power supply BB217.

[0123] Specific implementation 3: New CC combination switch circuit

[0124] In each of the single-chip microcomputer circuits, each of the optocoupler groups is controlled by a driving optocoupler; the positive input terminal of the driving optocoupler is connected to the VCC pin, and the negative input terminal of the driving optocoupler is connected to the output terminal corresponding to the single-chip microcomputer circuit; in each of the optocoupler groups, the positive input terminals of all the optocouplers are combined and connected to the negative output terminal of the driving optocoupler; the positive output terminal of the driving optocoupler is connected to the VCC pin of the single-chip microcomputer circuit; the negative input terminal of each optocoupler in each of the optocoupler groups is connected one-to-one to different partitions of relatively independent non-common carbon film contacts under the corresponding conductor key; the common carbon film contact is connected to the output terminal corresponding to the single-chip microcomputer circuit through a directional diode.

[0125] In each switching circuit, the positive and negative output pins of each optocoupler in the optocoupler group are respectively combined with the same output pins of the optocouplers at the same position in other optocoupler groups in the same circuit, using the matrix key rules of traditional electronic keyboard instruments, and then connected to the corresponding pins of the relevant sound source chip.

[0126] Working principle of the new CC combination switch circuit:

[0127] In a two-channel or multi-channel single-chip microcomputer switching circuit, when a finger wearing a conductive glove presses a key, it is equivalent to the high and low level control lines inputting a high level or low level to the corresponding input end of the programmed single-chip microcomputer circuit through the conductive keyboard. Taking the input of a low level as an example, the matching single-chip microcomputer circuit detects the input signal and controls the corresponding output end to output a low level.

[0128] The 5V signal on the Vcc pin first passes through the input and output ends of the driver optocoupler and then connects to the output end of the microcontroller circuit to form a current loop to start the driver optocoupler. After the driver optocoupler is started, the 5V signal on the Vcc pin is connected to the positive input end of the first optocoupler and the second optocoupler through the positive and negative output pins of the driver optocoupler. Then, the 5V signal is further transmitted to the carbon film contact in area A connected to it through the negative input end of the first optocoupler, and the 5V signal is transmitted to the carbon film contact in area B connected to it through the negative input end of the second optocoupler. Under the action of the conductive rubber, the carbon film contacts in areas A and C and the carbon film contacts in areas B and C are turned on in turn, transmitting the 5V signal from the vcc pin to the carbon film contacts in area C. The carbon film contacts in area C with the 5V signal are connected to the output end corresponding to the single-chip microcomputer circuit through a diode, forming a current loop with the low-level signal at the output end, and further starting the first optocoupler and the second optocoupler in turn. Subsequently, the pin wires corresponding to the sound source chip connected to the output ends of the first optocoupler and the second optocoupler will also be turned on in turn, starting the circuit inside the sound source chip and playing back the sampled sound.

[0129] By selecting a switching circuit that combines a single-chip microcomputer circuit and an optocoupler group, and applying a directional diode, there is no need for the current direction of the DC power supply to be opposite, nor is there a need to apply an optocoupler normally closed solid-state relay. This can prevent two or more optocoupler groups corresponding to the same key from forming a current loop when different high and low level control lines touch the key.

[0130] Because the input and output ends of the microcontroller are not like the positive and negative poles of a DC power supply, which have the physical conduction phenomenon, in two or more microcontroller circuits, different high and low level control lines touch the keys at the same time. Even though common carbon film contacts are used, no current loop will be formed between the related microcontroller circuits.

[0131] Each MCU needs to be programmed, and communication needs to be established between them to allow multiple control lines to share the same set of input IO ports without interfering with each other. For example, the application of MCU circuits in electronic keyboard instruments uses a six-channel 61-key electronic piano as an example: it is implemented by six groups of MCU circuits. Each group of MCU circuits includes 61 input terminals and 61 output terminals corresponding to the keys, as well as a common point. When the common point touches one or more input terminals, a current loop signal is formed. This group of signals is collected by the MCU and output to this group.

[0132] Take one of the groups as an example: it mainly uses the high-speed polling control method of the microcontroller io pin, and can complete the corresponding operation within a dozen microseconds. When a group of microcontrollers receives an executable operation instruction, it sets the common point to a low level, and then reads 61 input signals through 8 74HC245s respectively, stores the read results in the register, and then outputs the read signal through 8 74HC573s. If the input signal changes, the optocoupler connected to the output end will also change accordingly. When the instruction received by the microcontroller is not in line with its own instruction, the microcontroller will set the common point to a high level, and this group of circuits will stop working. The same principle applies to the other groups.

[0133] The principle of the first group of single-chip microcomputer circuits is: it will actively issue instructions to control the working status of the six single-chip microcomputers, and will change the instructions issued at intervals to let all the single-chip microcomputers work in turn. In this way, a circuit is realized in which 61 times 6 groups of signals are collected in this group, but the outputs will not interfere with each other.

[0134] Figure 3 This is a schematic diagram of the structure of the new CC combination switch circuit of the electronic keyboard instrument

[0135] In the figure, CC101 is the conductor keyboard. CC102 is the carbon film contact in area A. CC103 is the carbon film contact in area C. CC104 is the carbon film contact in area B. CC105 is the conductor glove. CC106 is the wire input terminal on the conductor glove. CC107 is the microcontroller circuit. CC108 is the input terminal of the microcontroller circuit. CC109 is the output terminal of the microcontroller circuit. CC110 is the high and low level control line of the microcontroller circuit. CC111 is the VCC pin of the microcontroller circuit. CC112 is the driver optocoupler. CC113 is the first optocoupler. CC114 is the second optocoupler. CC115 is a diode connected to the carbon film contact in area C. CC116 is the sound source chip. CC117 is the pin of the sound source chip in area A. CC118 is the pin of the sound source chip in area C. CC119 is the pin of the sound source chip in area B.

[0136] In the implementation of the new CC combination switch circuit:

[0137] (1) Two or more sound source chips are used, corresponding to the left and right hands or each finger of the keyboard instrument respectively, and all the sound source chips share a layer of conductor keys CC101 and carbon film contacts under the keys.

[0138] (2) Taking a single-tone dual-velocity electronic keyboard instrument as an example, the carbon film contacts under the keys are divided into relatively independent carbon film contacts in area A CC102, relatively independent carbon film contacts in area C CC103, and relatively independent carbon film contacts in area B CC104. Among them, the carbon film contacts in area C are common carbon film contacts, and the carbon film contacts in areas A and B are non-common carbon film contacts.

[0139] (3) A switching circuit is set between the carbon film contacts under the keys and the sound source chip CC106 corresponding to the left and right hands or different fingers playing the keyboard instrument. The switching circuit includes a single-chip microcomputer circuit CC107 and an optocoupler group with the same number of keys.

[0140] (4) In two or more single-chip microcomputer circuits CC107, the input terminals CC108 at the same position are combined together and connected to the corresponding conductor keys CC101 in sequence through wires. (For example: the first input terminals of different single-chip microcomputer circuits are combined together and connected to the first conductor key; the second input terminals of different single-chip microcomputer circuits are combined together and connected to the second conductor key, etc.)

[0141] (5) In the left and right channel or multi-channel switching circuit, each optocoupler group in each switching circuit includes a first optocoupler corresponding to the carbon film contacts in area A and area C below the keyboard and a second optocoupler corresponding to the carbon film contacts in area B and area C below the keyboard.

[0142] (6) In the single-tone dual-keyboard velocity sensing structure, each optocoupler group of the new CC combination switch circuit includes three optocouplers. We call the first optocoupler the driving optocoupler CC112, the second optocoupler the first optocoupler CC113, and the third optocoupler the second optocoupler CC114.

[0143] (7) In each switch circuit, the positive input terminal and the positive output terminal of the driver optocoupler CC112 are connected to the VCC pin CC111 of the single-chip microcomputer circuit CC107, the negative input terminal of the driver optocoupler CC112 is connected to the corresponding output terminal CC109 of the single-chip microcomputer circuit CC107, and the negative output terminal of the driver optocoupler CC112 is connected to the positive input terminals of the first optocoupler CC113 and the second optocoupler CC114. When the driver optocoupler CC112 is turned on, it provides a VCC signal to the positive input terminals of the first and second optocouplers.

[0144] (8) The negative electrode of the input terminal of the first optocoupler CC113 in the optocoupler group is connected to the carbon film contact CC102 in area A under the corresponding key, and the negative electrode of the input terminal of the second optocoupler CC114 is connected to the carbon film contact CC104 in area B under the corresponding key.

[0145] (9) In all optocoupler groups, the positive output pin of the first optocoupler CC113 and the positive output pin of the first optocoupler CC113 in other optocoupler groups in the same circuit are matrix-synthesized according to the matrix key-pressing rule of a traditional electronic keyboard instrument, and then connected to the corresponding pin in the A-zone pin CC117 of the relevant sound source chip CC116; the negative output pin of the first optocoupler CC113 and the negative output pin of the first optocoupler CC113 in other optocoupler groups in the same circuit are matrix-synthesized according to the matrix key-pressing rule of a traditional electronic keyboard instrument, and then connected to the corresponding pin in the C-zone pin CC118 of the relevant sound source chip CC116;

[0146] In all optocoupler groups, the positive output pin of the second optocoupler CC114 and the positive output pin of the second optocoupler CC114 in other optocoupler groups in the same circuit are synthesized through a matrix, and then connected to the corresponding pin in the B-area pin CC119 of the relevant sound source chip CC116; the negative output pin of the second optocoupler CC114 and the negative output pin of the second optocoupler CC114 in other optocoupler groups in the same circuit are synthesized through a matrix, and then connected to the corresponding pin in the C-area pin CC118 of the relevant sound source chip.

[0147] (10) A directional diode CC115 needs to be arranged between the carbon film contact CC103 in the C area under the key and the output terminal CC109 corresponding to each microcontroller circuit CC107.

[0148] (11) The conductor glove CC105 is used to play a stereo electronic keyboard instrument. Each microcontroller circuit is connected to the corresponding wire input terminal CC106 on the conductor glove CC105 through a high and low level control line CC110.

[0149] (12) A two-channel stereo electronic keyboard instrument requires two relatively independent sound source chips and two single-chip microcomputer circuits. The carbon film contacts under the keys are connected to the two sound source chips through the two single-chip microcomputer circuits, which can realize left and right two-channel stereo.

[0150] (13) A six-channel stereo electronic keyboard instrument requires six relatively independent sound source chips and six single-chip microcomputer circuits. The six single-chip microcomputer circuits lead out six control lines and are connected to different wire input terminals on the conductor gloves of both hands. The thumb finger wires on the left and right conductor gloves correspond to a single-chip microcomputer circuit respectively, and the finger wires of the index finger and middle finger on the left and right conductor gloves correspond to a single-chip microcomputer circuit respectively. The finger wires of the ring finger and little finger on the left and right conductor gloves correspond to a single-chip microcomputer circuit respectively. The carbon film contacts under the keys are connected to the six sound source chips through the six single-chip microcomputer circuits, so that six-channel stereo can be achieved.

[0151] (14) A ten-channel stereo electronic keyboard instrument requires ten relatively independent sound source chips and ten single-chip microcomputer circuits. The ten single-chip microcomputer circuits lead out ten control lines and connect them to different wire input terminals on the conductor gloves of both hands. Each finger wire on the left and right conductor gloves corresponds to a single-chip microcomputer circuit. The carbon film contacts under the keys are connected to the ten sound source chips through the ten single-chip microcomputer circuits, which can realize ten-channel stereo.

[0152] (15) The single-chip microcomputer circuit consists of a single-chip microcomputer and an expansion chip. The single-chip microcomputer is selected as a 51 single-chip microcomputer, and the optocoupler is selected as a P281 chip optocoupler. Other similar available models can also be selected.

[0153] Specific implementation 4: Old CC combination switch circuit

[0154] In each of the single-chip microcomputer circuits, the positive input terminals of all the optocouplers in the optocoupler group are combined together and connected to the VCC pin of the single-chip microcomputer circuit; the negative input terminals of all the optocouplers in the optocoupler group are combined together and connected to the corresponding output terminals of the single-chip microcomputer circuit.

[0155] In each switching circuit, one pin of each optocoupler output end in the optocoupler group is connected to the corresponding carbon film contact end wire; another pin of each optocoupler output end in the optocoupler group is matrix synthesized with the same output end pin of the optocoupler at the same position in other optocoupler groups in the same circuit according to the matrix key rules of traditional electronic keyboard instruments, and then connected to the corresponding pin of the relevant sound source chip.

[0156] Working principle of the old CC combination switch circuit:

[0157] In a two-channel or multi-channel single-chip microcomputer switching circuit, when a finger wearing a conductive glove presses a key, it is equivalent to the high and low level control lines inputting a high level or low level to the corresponding input end of the programmed single-chip microcomputer circuit through the conductive keyboard. Taking the input of a low level as an example, the matching single-chip microcomputer circuit detects the input signal and controls the corresponding output end to output a low level.

[0158] In each switch circuit, the VCC pin wire is connected to the positive input terminal of the optocoupler in each optocoupler group, and the negative input terminal of the optocoupler in each optocoupler group is connected to the corresponding output terminal of the single-chip microcomputer circuit.

[0159] A combination of two or more single-chip microcomputer circuits, when the left or right hand or each finger presses different keys at the same time, will activate the optocoupler in the optocoupler group corresponding to the key in the relevant single-chip microcomputer circuit, and further connect the connection between the carbon film contacts of different partitions and the corresponding pins of the sound source chip through the output end of the optocoupler in the optocoupler group, thereby realizing two-channel or multi-channel stereo.

[0160] By selecting a switching circuit combining a single-chip microcomputer circuit and an optocoupler group, there is no need for the DC power supply current to be in the opposite direction, and there is no need to use an optocoupler normally closed solid-state relay to avoid the formation of a current loop when two or more optocoupler groups corresponding to the same key touch the key with different high and low level control lines.

[0161] For the principles of single-chip microcomputer circuits used in electronic keyboard instruments, please refer to the description of single-chip microcomputer related contents in the working principle of the new CC combination single-chip microcomputer circuit for details.

[0162] Figure 4 This is a schematic diagram of the structure of the old CC combination switch circuit of an electronic keyboard instrument

[0163] In the figure, CC201 is the conductor keyboard. CC202 is the carbon film contact in area A. CC203 is the carbon film contact in area C. CC204 is the carbon film contact in area B. CC205 is the conductor glove. CC206 is the wire input terminal on the conductor glove. CC207 is the microcontroller circuit. CC208 is the input terminal of the microcontroller circuit. CC209 is the output terminal of the microcontroller circuit. CC210 is the high and low level control line of the microcontroller circuit. CC211 is the VCC pin of the microcontroller circuit. CC212 is the first optocoupler. CC213 is the second optocoupler. CC214 is the third optocoupler. CC215 is the sound source chip. CC216 is the pin of the sound source chip in area A. CC217 is the pin of the sound source chip in area C. CC218 is the pin of the sound source chip in area B.

[0164] In the implementation of the old CC combination switch circuit:

[0165] (1) Two or more sound source chips are used, corresponding to the left and right hands or each finger of the keyboard instrument, and all the sound source chips share a layer of conductor keys CC201 and carbon film contacts under the keys.

[0166] (2) Taking a single-tone dual-velocity electronic keyboard instrument as an example, the carbon film contacts under the keys are divided into relatively independent carbon film contacts in area A CC202, relatively independent carbon film contacts in area C CC203, and relatively independent carbon film contacts in area B CC204. Among them, the carbon film contacts in area C are common carbon film contacts, and the carbon film contacts in areas A and B are non-common carbon film contacts.

[0167] (3) A switching circuit is set between the carbon film contacts under the keys and the sound source chip CC215 corresponding to the left and right hands or different fingers playing the keyboard instrument. The switching circuit includes a single-chip microcomputer circuit CC207 and an optocoupler group with the same number of keys.

[0168] (4) In two or more single-chip computer circuits CC207, the input terminals CC208 at the same position are combined together and connected to the corresponding conductor keyboards CC201 in sequence through wires.

[0169] (5) In the left channel, right channel or multi-channel switching circuit, each optocoupler group in each switching circuit includes a first optocoupler CC212 corresponding to the carbon film contact in area A below the keyboard, a second optocoupler CC213 corresponding to the carbon film contact in area C below the keyboard, and a third optocoupler CC214 corresponding to the carbon film contact in area B below the keyboard.

[0170] (6) The VCC pin CC211 of each single-chip microcomputer circuit CC207 is connected to the positive input terminals of the three optocouplers in the optocoupler group, and the negative input terminals of the three optocouplers are connected to the corresponding output terminals CC209 of the single-chip microcomputer circuit CC207.

[0171] (7) The negative electrode of the output terminal of the first optocoupler CC212 in each optocoupler group is connected to the carbon film contact CC202 in area A under the corresponding key, the positive electrode of the output terminal of the second optocoupler CC213 is connected to the carbon film contact CC203 in area C under the corresponding key, and the negative electrode of the output terminal of the third optocoupler CC214 is connected to the carbon film contact CC204 in area B under the corresponding key.

[0172] (8) In each optocoupler group of each switching circuit, the positive output terminal of the first optocoupler CC212 and the positive output terminals of the first optocoupler CC212 in other optocoupler groups of the same circuit are matrix-synthesized according to the matrix keying rule of a traditional electronic keyboard instrument, and then connected to the corresponding pin in the A-zone pin CC216 of the relevant sound source chip CC215;

[0173] The negative output pin of the second optocoupler CC213 and the negative output pin of the second optocoupler CC213 in other optocoupler groups in the same circuit are matrix-synthesized using the matrix keystroke rule of a traditional electronic keyboard instrument, and then connected to the corresponding pin in the C-zone pin CC217 of the related sound source chip CC215;

[0174] The positive output terminal of the third optocoupler CC214 and the positive output terminal pin of the third optocoupler CC214 in other optocoupler groups in the same circuit are matrix synthesized according to the matrix key rules of traditional electronic keyboard instruments, and then connected to the corresponding pin in the B area pin CC218 in the relevant sound source chip CC215.

[0175] (9) The conductor glove CC205 is used to play a stereo electronic keyboard instrument. Each microcontroller circuit CC207 needs to lead out a high and low level control line CC210 to be connected to the wire input terminal CC206 on the conductor glove.

[0176] (10) A two-channel stereo electronic keyboard instrument requires two relatively independent sound source chips and two single-chip microcomputer circuits. The two single-chip microcomputer circuits lead out two control lines, which are connected one-to-one to the wire input terminals CC206 on the conductor gloves of both hands. The carbon film contacts under the keys are connected to the two sound source chips through the two single-chip microcomputer circuits, which can realize left and right two-channel stereo.

[0177] (11) A six-channel stereo electronic keyboard instrument requires six relatively independent sound source chips and six single-chip microcomputer circuits. The six single-chip microcomputer circuits lead out six control lines and are connected to different wire input terminals on the conductor gloves of both hands. The thumb wires on the left and right conductor gloves correspond to one single-chip microcomputer circuit each, the index finger and middle finger wires on the left and right conductor gloves together correspond to one single-chip microcomputer circuit each, and the ring finger and little finger wires on the left and right conductor gloves together correspond to one single-chip microcomputer circuit each. The carbon film contacts under the keys are connected to the six sound source chips through the six single-chip microcomputer circuits, so that six-channel stereo can be achieved.

[0178] (12) A ten-channel stereo electronic keyboard instrument requires ten relatively independent sound source chips and ten single-chip microcomputer circuits. The ten single-chip microcomputer circuits lead out ten control lines and connect them to different wire input terminals on the conductor gloves of both hands. Each finger wire on the left and right conductor gloves corresponds to a single-chip microcomputer circuit. The carbon film contacts under the keys are connected to the ten sound source chips through the ten single-chip microcomputer circuits, which can realize ten-channel stereo.

[0179] Specific embodiment 5: AA combination keyboard partition fixed switch circuit

[0180] In the left and right channel switching circuits, the positive input terminals of all the optocouplers in each optocoupler group are combined together and connected to the positive wire of the DC power supply; the negative input terminal of each optocoupler in each optocoupler group is connected one-to-one to different partitions of relatively independent non-common carbon film contacts under the corresponding keys; the common carbon film contacts under the corresponding keys are combined together and connected to the negative wire of the DC power supply.

[0181] In each switching circuit, the positive and negative output pins of each optocoupler in the optocoupler group are respectively combined with the same output pins of the optocouplers at the same position in other optocoupler groups in the same circuit, using the matrix key rules of traditional electronic keyboard instruments, and then connected to the corresponding pins of the relevant sound source chip.

[0182] The left or right hand of the keyboard player presses the keys in the corresponding area, and the conductive rubber covers the carbon film contacts, which can control the corresponding optocoupler group in the related switching circuit, and further control the corresponding pins of the related sound source chip.

[0183] Working principle of AA combination keyboard partition fixed switch circuit:

[0184] The positive wire of the DC power supply will be connected one-to-one with the different partitions of the non-common carbon film contacts under the keyboard through the input end of the optocoupler in each optocoupler group connected to it. When the key is pressed, the different partitions on the non-common carbon film contact transfer the positive charge to the common carbon film contact through the conductive rubber. The common carbon film contact is connected to the negative wire of the DC power supply, forming a current loop, which successively activates the optocouplers in the corresponding optocoupler groups under the keyboard, and further turns on the corresponding pins of the relevant sound source chip connected to the output end of the optocoupler. The fingers of both hands press the keys in their respective keyboard areas, which can realize the pronunciation of the left channel when the left hand touches the key, and the pronunciation of the right channel when the right hand touches the key.

[0185] Figure 5 This is a structural diagram of the AA combination partition fixed switch circuit of the electronic keyboard instrument

[0186] In the figure, AA101 is the carbon film contact in Area A. AA102 is the carbon film contact in Area C. AA103 is the carbon film contact in Area B. AA104 is the DC power supply. AA105 is the first optocoupler for the left channel. AA106 is the second optocoupler for the left channel. AA107 is the left channel audio source chip. AA108 is the pin of the left channel audio source chip in Area A. AA109 is the pin of the left channel audio source chip in Area C. AA110 is the pin of the left channel audio source chip in Area B. AA111 is the first optocoupler for the right channel. AA112 is the second optocoupler for the right channel. AA113 is the right channel audio source chip. AA114 is the pin of the right channel audio source chip in Area A. AA115 is the pin of the right channel audio source chip in Area C. AA116 is the pin of the right channel audio source chip in Area B.

[0187] In the implementation of the AA combination keyboard partition fixed switch circuit:

[0188] (1) Two or two groups of relatively independent sound source chips are used, corresponding to the left and right hands playing the keyboard instrument respectively, and the single-layer keyboard or double-layer keyboard of the electronic keyboard instrument is divided into two groups. Each group of keyboards and the carbon film contacts thereunder correspond to one or a group of the above-mentioned sound source chips.

[0189] (2) In the single-tone dual-velocity sensing mode, the carbon film contacts under the keys are divided into area A carbon film contacts AA101, area C carbon film contacts AA102 and area B carbon film contacts AA103. The area A carbon film contacts and area B carbon film contacts under each key are relatively independent. All area C carbon film contacts AA102 under each group of keyboards are combined together and connected to the negative wire of the DC power supply AA104 shared by the left and right channels.

[0190] (3) A switch circuit is provided between the carbon film contact and each of the sound source chips. Each switch circuit includes a DC power supply AA104 and a photocoupler group that is the same as the number of partitioned keys.

[0191] (4) In the left and right channel switching circuits, each optocoupler group in each switching circuit includes a first optocoupler corresponding to the carbon film contacts in area A and area C below the keyboard and a second optocoupler corresponding to the carbon film contacts in area B and area C below the keyboard.

[0192] (5) Each optocoupler group includes two optocouplers corresponding to the carbon film contact AA101 in area A and the carbon film contact AA103 in area B, referred to as the first optocoupler and the second optocoupler. The positive input terminals of the two optocouplers are connected to the positive lead of the DC power supply AA104, and the negative input terminals of the two optocouplers are connected one-to-one to the relatively independent carbon film contact AA101 in area A and the carbon film contact AA103 in area B under the corresponding keyboard.

[0193] (6) In the left channel optocoupler group, the positive output pin of the first optocoupler AA105 and the positive output pin of the first optocoupler AA105 in other optocoupler groups are matrix-synthesized according to the matrix key rules of a traditional electronic keyboard instrument, and then connected to the corresponding pin in the A-zone pin AA108 of the left channel sound source chip AA107; the negative output pin of the first optocoupler AA105 and the negative output pin of the first optocoupler AA105 in other optocoupler groups are matrix-synthesized according to the matrix key rules of a traditional electronic keyboard instrument, and then connected to the corresponding pin in the C-zone pin AA109 of the left channel sound source chip AA107.

[0194] (7) In the left channel optocoupler group, the positive output pin of the second optocoupler AA106 and the positive output pin of the second optocoupler AA106 in other optocoupler groups are matrix-synthesized according to the matrix key rules of a traditional electronic keyboard instrument, and then connected to the corresponding pin in the B area pin AA110 in the left channel sound source chip AA107; the negative output pin of the second optocoupler AA106 and the negative output pin of the second optocoupler AA106 in other optocoupler groups are matrix-synthesized according to the matrix key rules of a traditional electronic keyboard instrument, and then connected to the corresponding pin in the C area pin AA109 in the left channel sound source chip AA107.

[0195] (8) In the right channel optocoupler group, the positive output pin of the first optocoupler AA111 and the positive output pin of the first optocoupler AA111 in other optocoupler groups are matrix-synthesized according to the matrix key rules of a traditional electronic keyboard instrument, and then connected to the corresponding pin in the A-zone pin AA114 of the right channel sound source chip AA113; the negative output pin of the first optocoupler AA111 and the negative output pin of the first optocoupler AA111 in other optocoupler groups are matrix-synthesized according to the matrix key rules of a traditional electronic keyboard instrument, and then connected to the corresponding pin in the C-zone pin AA115 of the right channel sound source chip AA113.

[0196] (9) In the right channel optocoupler group, the positive output pin of the second optocoupler AA112 and the positive output pin of the second optocoupler AA112 in other optocoupler groups are matrix-synthesized according to the matrix key rules of a traditional electronic keyboard instrument, and then connected to the corresponding pin in the B area pin AA116 of the right channel sound source chip AA113; the negative output pin of the second optocoupler AA112 and the negative output pin of the second optocoupler AA112 in other optocoupler groups are matrix-synthesized according to the matrix key rules of a traditional electronic keyboard instrument, and then connected to the corresponding pin in the C area pin AA115 of the right channel sound source chip AA113.

[0197] Specific embodiment 6: AA combination keyboard partition adjustable switch circuit

[0198] In the left channel switching circuit, the positive input terminals of all the optocouplers in each optocoupler group are combined and connected to the negative output terminals of the corresponding optocoupler normally closed solid-state relays; the positive output terminals of the corresponding optocoupler normally closed solid-state relays are connected to the positive lead of a DC power supply; the negative input terminals of each optocoupler in each optocoupler group are connected one-to-one to different partitions of relatively independent non-common carbon film contacts under the corresponding keys;

[0199] In the right channel switching circuit, the positive input terminals of all the optocouplers in each optocoupler group are combined and connected to the negative output terminals of the corresponding common optocouplers; the positive output terminals of the corresponding common optocouplers are connected to the positive lead of the DC power supply; the negative input terminals of each optocoupler in each optocoupler group are connected one-to-one to different partitions of relatively independent non-common carbon film contacts under the corresponding keys;

[0200] The positive input terminals of the optocoupler normally closed solid-state relay in the left channel switch circuit and the ordinary optocoupler in the right channel switch circuit under the same key are combined together and connected to the positive wire of the DC power supply; the negative input terminals are combined together and connected to the negative wire of the DC power supply through a controllable switch; by controlling the two-in-one switches in sequence, the keyboard partition of the left keyboard area or the right keyboard area can be expanded.

[0201] In each switching circuit, the positive and negative output pins of each optocoupler in the optocoupler group are respectively combined with the same output pins of the optocouplers at the same position in other optocoupler groups in the same circuit, using the matrix key rules of traditional electronic keyboard instruments, and then connected to the corresponding pins of the relevant sound source chip.

[0202] Working principle of AA combination keyboard partition adjustable switch circuit:

[0203] The switch circuit includes a left channel switch circuit and a right channel switch circuit corresponding to the left and right hands, and each switch circuit corresponds to one or a group of sound source chips.

[0204] When the optocoupler normally closed solid-state relay that controls the left channel optocoupler group and the ordinary optocoupler that controls the right channel optocoupler group are powered on, the optocoupler group corresponding to the left channel is disconnected from the power supply, and the optocoupler group corresponding to the right channel is powered on, allowing the keyboard area of ​​the right channel to expand to the left channel. Conversely, when the optocoupler normally closed solid-state relay that controls the left channel optocoupler group and the ordinary optocoupler that controls the right channel optocoupler group are powered off, the optocoupler group corresponding to the left channel is powered on, and the optocoupler group corresponding to the right channel is disconnected from the power supply, allowing the keyboard area of ​​the left channel to expand to the right channel. If you want to expand the keyboard area of ​​the left channel, you need to turn off the two-in-one switch from left to right in sequence. If you want to expand the keyboard area of ​​the right channel, you need to turn on the two-in-one switch from right to left in sequence.

[0205] Figure 6 This is a schematic diagram of the structure of the AA combination keyboard partition adjustable switch circuit of the electronic keyboard instrument

[0206] In the figure, AA201 is the carbon film contact in area A. AA202 is the carbon film contact in area C. AA203 is the carbon film contact in area B. AA204 is a DC power supply. AA205 is a controllable switch. AA206 is the first optocoupler for the left channel. AA207 is the second optocoupler for the left channel. AA208 is the normally closed solid-state relay for the left channel optocoupler. AA209 is the left channel audio source chip. AA210 is a pin in area A of the left channel audio source chip. AA211 is a pin in area C of the left channel audio source chip. AA212 is a pin in area B of the left channel audio source chip. AA213 is the first optocoupler for the right channel. AA214 is the second optocoupler for the right channel. AA215 is the right channel common control optocoupler. AA216 is the right channel audio source chip. AA217 is a pin in area A of the right channel audio source chip. AA218 is a pin in area C of the right channel audio source chip. AA219 is the pin of area B of the right channel audio source chip.

[0207] In the implementation of the AA combination keyboard partition adjustable switch circuit:

[0208] (1) Two or two groups of relatively independent sound source chips are used, corresponding to the left hand and the right hand playing the keyboard instrument respectively, and the two or two groups of relatively independent sound source chips share a layer of keys.

[0209] (2) Taking a single-tone dual-velocity sensing electronic keyboard instrument as an example, the carbon film contacts under the keys are divided into area A carbon film contacts AA201, area C carbon film contacts AA202 and area B carbon film contacts AA203, wherein the area A carbon film contacts AA201 and area B carbon film contacts AA203 under each key are relatively independent, wherein the area C carbon film contacts AA202 under all the keys are combined and connected to the negative wire of the DC power supply AA204.

[0210] (3) Two sets of switch circuits corresponding to the left and right channels are set between the carbon film contacts and the two sound source chips. Each set of switch circuits includes a common DC power supply AA204 and a group of optocouplers that matches the number of piano keys.

[0211] (4) In the left and right channel switching circuits, each optocoupler group in each switching circuit includes a first optocoupler corresponding to the carbon film contacts in area A and area C below the keyboard and a second optocoupler corresponding to the carbon film contacts in area B and area C below the keyboard.

[0212] (5) In the left channel switching circuit, taking an 88-key electronic keyboard instrument as an example, the positive lead of the DC power supply passes through the positive and negative output terminals of 88 optocoupler normally closed solid-state relays AA208 and is connected to the positive input terminal of the optocoupler in the 88 optocoupler groups of the left channel.

[0213] (6) In the right channel switching circuit, taking an 88-key electronic keyboard instrument as an example, the positive wire of the DC power supply passes through the positive and negative output terminals of 88 common control optocouplers AA215 and is connected to the positive input terminal of the optocoupler in the 88 optocoupler groups of the right channel.

[0214] (7) The negative electrode of the input terminal of the first optocoupler AA206 in the left channel optocoupler group is connected to the relatively independent carbon film contact AA201 in the A area under the corresponding keyboard, and the negative electrode of the input terminal of the second optocoupler AA207 is connected to the relatively independent carbon film contact AA203 in the B area under the corresponding keyboard.

[0215] (8) The negative electrode of the input terminal of the first optocoupler AA213 in the right channel optocoupler group is connected to the relatively independent carbon film contact AA201 in the A area under the corresponding keyboard, and the negative electrode of the input terminal of the second optocoupler AA214 is connected to the relatively independent carbon film contact AA203 in the B area under the corresponding keyboard.

[0216] (9) The positive poles of the input terminals of the optocoupler normally closed solid-state relay AA208 and the common control optocoupler AA215 are connected to the positive pole wire of the DC power supply AA204 through wires, and the negative poles of the input terminals of the optocoupler normally closed solid-state relay AA208 and the common control optocoupler AA215 are also combined together and connected to the negative pole wire of the DC power supply AA204 through a relatively independent controllable switch AA205 or other switch.

[0217] (10) In the left channel optocoupler group, the positive output pin of the first optocoupler AA206 and the positive output pin of the first optocoupler AA206 in other optocoupler groups are matrix-synthesized according to the matrix keying rules of a traditional electronic keyboard instrument, and then connected to the corresponding pin in the A-zone pin AA210 of the left channel sound source chip AA209. The negative output pin of the first optocoupler AA206 and the negative output pin of the first optocoupler AA206 in other optocoupler groups are matrix-synthesized according to the matrix keying rules of a traditional electronic keyboard instrument, and then connected to the corresponding pin in the C-zone pin AA211 of the left channel sound source chip AA209.

[0218] (11) In the left channel optocoupler group, the positive output pin of the second optocoupler AA207 and the positive output pin of the second optocoupler AA207 in other optocoupler groups are matrix-synthesized according to the matrix key rules of a traditional electronic keyboard instrument, and then connected to the corresponding pin in the B area pin AA212 of the left channel sound source chip AA209; the negative output pin of the second optocoupler AA207 and the negative output pin of the second optocoupler AA207 in other optocoupler groups are matrix-synthesized according to the matrix key rules of a traditional electronic keyboard instrument, and then connected to the corresponding pin in the C area pin AA211 of the left channel sound source chip AA209.

[0219] (12) In the right channel optocoupler group, the positive output pin of the first optocoupler AA213 and the positive output pin of the first optocoupler AA213 in other optocoupler groups are matrix-synthesized according to the matrix key rules of a traditional electronic keyboard instrument, and then connected to the corresponding pin in the A-zone pin AA217 of the right channel sound source chip AA216; the negative output pin of the first optocoupler AA213 and the negative output pin of the first optocoupler AA213 in other optocoupler groups are matrix-synthesized according to the matrix key rules of a traditional electronic keyboard instrument, and then connected to the corresponding pin in the C-zone pin AA218 of the right channel sound source chip AA216;

[0220] (13) In the right channel optocoupler group, the positive output pin of the second optocoupler AA214 and the positive output pin of the second optocoupler AA214 in other optocoupler groups are matrix-synthesized according to the matrix key rules of traditional electronic keyboard instruments, and then connected to the corresponding pin in the B area pin AA219 of the right channel sound source chip AA216; the negative output pin of the second optocoupler AA214 and the negative output pin of the second optocoupler AA214 in other optocoupler groups are matrix-synthesized according to the matrix key rules of traditional electronic keyboard instruments, and then connected to the corresponding pin in the C area pin AA218 of the right channel sound source chip AA216.

[0221] Specific implementation 7: Basic version of the new AB combination switch circuit

[0222] In the left-channel switching circuit, the positive input terminals of all optocouplers in the optocoupler group are combined and connected to the positive wire of the left-channel DC power supply. The negative input terminal of each optocoupler in the optocoupler group is connected one-to-one to different partitions of relatively independent non-common carbon film contacts under the corresponding conductor key. The common carbon film contacts are connected to the corresponding conductor keys. The negative wire of the left-channel DC power supply serves as the control line of the switching circuit and is connected to the wire input terminal on the left-channel conductor glove.

[0223] In the right channel switching circuit, the positive input terminals of all the optocouplers in each optocoupler group are combined and connected to the negative output terminal of a corresponding optocoupler normally closed solid-state relay; the positive output terminal of the corresponding optocoupler normally closed solid-state relay is connected to the positive wire of the right channel DC power supply; the negative input terminal of each optocoupler in each optocoupler group is connected one-to-one to different partitions of the relatively independent non-common carbon film contacts under the corresponding conductor key; the common carbon film contact is connected to the negative wire of the right channel DC power supply through a directional diode.

[0224] The positive input terminal of the optocoupler normally closed solid-state relay is connected to the positive wire of the DC power supply in the left channel switch circuit; the negative input terminal of the optocoupler normally closed solid-state relay is connected to the corresponding conductor key.

[0225] In each switching circuit, the positive and negative output pins of each optocoupler in the optocoupler group are respectively combined with the same output pins of the optocouplers at the same position in other optocoupler groups in the same circuit, using the matrix key rules of traditional electronic keyboard instruments, and then connected to the corresponding pins of the relevant sound source chip.

[0226] Working principle of the basic version of the new AB combination switch circuit:

[0227] The new AB combination switch circuit described above includes an A-type switch circuit corresponding to the right channel and a B-type switch circuit corresponding to the left channel.

[0228] When a left hand wearing a conductive glove presses a piano key, a current loop is formed and the optocoupler in the optocoupler group corresponding to the left channel is activated. Simultaneously, power is supplied to the optocoupler normally closed solid-state relay corresponding to the right channel switching circuit. This power is then turned off by the corresponding optocoupler normally closed solid-state relay in the right channel circuit.

[0229] When the right hand presses the piano key in the A-type switch circuit, the conductive rubber covers the carbon film contact, and the optocoupler in the optocoupler group corresponding to the right channel will form a current loop and be activated.

[0230] When the fingers of both hands press different keys at the same time, thanks to AQY412EH, no current loop will be formed between the left and right channel optocoupler groups corresponding to the same key, and all will be activated, thus ensuring the independence of the sound source.

[0231] In the left or right channel switching circuit, after the relevant optocoupler group is turned on when the key is pressed, the corresponding pins of the relevant sound source chip connected by wires at both ends of each optocoupler output will be turned on, and two-channel stereo sound can be played.

[0232] Figure 7 This is the structural diagram of the new AB combination switch circuit of the basic version of the electronic keyboard instrument

[0233] In the figure, AB101 is the conductor keyboard. AB102 is the carbon film contact in area A. AB103 is the carbon film contact in area C. AB104 is the carbon film contact in area B. AB105 is the left channel conductor glove. AB106 is the wire input terminal on the conductor glove. AB107 is the left channel DC power supply. AB108 is the first optocoupler for the left channel. AB109 is the second optocoupler for the left channel. AB110 is the left channel audio source chip. AB111 is the pin in area A of the left channel audio source chip. AB112 is the pin in area C of the left channel audio source chip. AB113 is the pin in area B of the left channel audio source chip. AB114 is the right channel DC power supply. AB115 is a directional diode. AB116 is the first optocoupler for the right channel. AB117 is the second optocoupler for the right channel. AB118 is the optocoupler normally closed solid-state relay. AB119 is the right channel audio source chip. AB120 is the pin for the right channel audio source chip in Area A. AB121 is the pin for the right channel audio source chip in Area C. AB122 is the pin for the right channel audio source chip in Area B.

[0234] In the implementation of the basic version of the new AB combination switch circuit:

[0235] (1) Two or two groups of relatively independent sound source chips are used, corresponding to the left hand and the right hand playing the keyboard instrument respectively, and the two or two groups of relatively independent sound source chips share a layer of conductor keys AB101 and carbon film contacts under the keys.

[0236] (2) Taking a dual-velocity-sensitive electronic keyboard instrument as an example, the carbon film contacts under the keys include relatively independent carbon film contacts in area A AB102, relatively independent carbon film contacts in area C AB103, and relatively independent carbon film contacts in area B AB104. Among them, the carbon film contacts in area C are common carbon film contacts, and the carbon film contacts in areas A and B are non-common carbon film contacts.

[0237] (3) A left-channel switching circuit is set between the carbon film contact and the left-channel sound source chip AB110, and a right-channel switching circuit is set between the carbon film contact and the right-channel sound source chip AB119. Each switching circuit includes an independent DC power supply and a set of optocouplers that matches the number of piano keys.

[0238] (4) In the left and right channel switching circuits, each optocoupler group in each switching circuit includes a first optocoupler corresponding to the carbon film contacts in area A and area C below the keyboard and a second optocoupler corresponding to the carbon film contacts in area B and area C below the keyboard.

[0239] (5) In the left channel switching circuit, the negative input terminal of the first optocoupler AB108 is connected to the carbon film contact AB102 in area A under the corresponding key, the negative input terminal of the second optocoupler AB109 is connected to the carbon film contact AB104 in area B under the corresponding key, the common carbon film contact AB103 in area C is connected to the corresponding conductor keyboard AB101, and the positive input terminals of the two optocouplers are directly connected to the positive wire of the DC power supply AB107.

[0240] (6) The left channel switching circuit uses a conductor keyboard AB101 and a conductor glove AB105. The negative wire of the left channel DC power supply AB107 is connected to the wire input terminal AB106 on the left hand conductor glove AB105.

[0241] (7) In the right channel switching circuit, the positive lead of the DC power supply AB114 is connected to the positive input terminals of the first optocoupler AB116 and the second optocoupler AB117 through the output terminals of the optocoupler normally closed solid-state relay AB118. The negative input terminal of the first optocoupler AB116 is connected to the carbon film contact AB102 in area A below the key. The negative input terminal of the second optocoupler AB117 is connected to the carbon film contact AB104 in area B below the key. The common carbon film contact AB103 in area C is connected to the negative lead of the right channel DC power supply AB114 through the directional diode AB115.

[0242] (8) The optocoupler normally closed solid-state relay AB118 is controlled by the left channel switch circuit, and its positive input terminal is connected to the positive wire of the left channel DC power supply AB107, and its negative input terminal is connected to the corresponding conductor keyboard AB101.

[0243] (9) In the left channel optocoupler group, the positive output pin of the first optocoupler AB108 and the positive output pin of the first optocoupler AB108 in other optocoupler groups are matrix-synthesized according to the matrix key rules of a traditional electronic keyboard instrument, and then connected to the corresponding pin in the A area pin AB111 of the left channel sound source chip; the negative output pin of the first optocoupler AB108 and the negative output pin of the first optocoupler AB108 in other optocoupler groups are matrix-synthesized according to the matrix key rules of a traditional electronic keyboard instrument, and then connected to the corresponding pin in the C area pin AB112 of the left channel sound source chip.

[0244] (10) In the left channel optocoupler group, the positive output pin of the second optocoupler AB109 and the positive output pin of the second optocoupler AB109 in other optocoupler groups are matrix-synthesized according to the matrix key rules of a traditional electronic keyboard instrument, and then connected to the corresponding pin in the B area pin AB113 of the left channel sound source chip AB110; the negative output pin of the second optocoupler AB109 and the negative output pin of the second optocoupler AB109 in other optocoupler groups are matrix-synthesized according to the matrix key rules of a traditional electronic keyboard instrument, and then connected to the corresponding pin in the C area pin AB112 of the left channel sound source chip AB110.

[0245] (11) In the right channel optocoupler group, the positive output pin of the first optocoupler AB116 and the positive output pin of the first optocoupler AB116 in other optocoupler groups are matrix-synthesized according to the matrix key rules of a traditional electronic keyboard instrument, and then connected to the corresponding pin in the A area pin AB120 in the right channel sound source chip AB119; the negative output pin of the first optocoupler AB116 and the negative output pin of the first optocoupler AB116 in other optocoupler groups are matrix-synthesized according to the matrix key rules of a traditional electronic keyboard instrument, and then connected to the corresponding pin in the C area pin AB121 in the right channel sound source chip AB119.

[0246] (12) In the right channel optocoupler group, the positive output pin of the second optocoupler AB117 and the positive output pin of the second optocoupler AB117 in other optocoupler groups are matrix-synthesized according to the matrix key rules of a traditional electronic keyboard instrument, and then connected to the corresponding pin in the B area pin AB122 of the right channel sound source chip AB119; the negative output pin of the second optocoupler AB117 and the negative output pin of the second optocoupler AB117 in other optocoupler groups are matrix-synthesized according to the matrix key rules of a traditional electronic keyboard instrument, and then connected to the corresponding pin in the C area pin AB121 of the right channel sound source chip AB119.

[0247] Specific implementation 8: Basic version of the old AB combination switch circuit

[0248] In the left channel switching circuit, the positive input terminals of all the optocouplers in each optocoupler group are combined together and connected to the positive wire of the left channel DC power supply; the negative input terminals of all the optocouplers in each optocoupler group are combined together and connected to the corresponding conductor key; the negative wire of the left channel DC power supply serves as the control line of the switching circuit and is connected to the wire input terminal on the left channel conductor glove;

[0249] In the right channel switching circuit, the positive input terminals of all the optocouplers in each optocoupler group are combined together and connected to the negative output terminal of the corresponding optocoupler normally closed solid-state relay; the positive output terminal of the corresponding optocoupler normally closed solid-state relay is connected to the positive wire of the right channel DC power supply; the negative input terminals of all the optocouplers in each optocoupler group are combined together and connected to the negative wire of the right channel DC power supply through a directional diode.

[0250] The positive input terminal of the optocoupler normally closed solid-state relay is connected to the positive wire of the DC power supply in the left channel switch circuit; the negative input terminal of the optocoupler normally closed solid-state relay is connected to the corresponding conductor key.

[0251] In each switching circuit, one pin of each optocoupler output end in the optocoupler group is connected to the corresponding carbon film contact end wire; another pin of each optocoupler output end in the optocoupler group is matrix synthesized with the same output end pin of the optocoupler at the same position in other optocoupler groups in the same circuit according to the matrix key rules of traditional electronic keyboard instruments, and then connected to the corresponding pin of the relevant sound source chip.

[0252] Working principle of the basic old AB combination switch circuit:

[0253] The old AB combination switch circuit mentioned above includes an A-type switch circuit corresponding to the right channel and a B-type switch circuit corresponding to the left channel.

[0254] When a left hand wearing a conductive glove presses a piano key, the optocoupler in the optocoupler group corresponding to the left channel forms a current loop and is activated. Simultaneously, the left hand activates the optocoupler normally closed solid-state relay corresponding to the right channel switching circuit. This in turn closes the optocoupler in the optocoupler group corresponding to the right channel under the same key, via the corresponding normally closed solid-state relay in the right channel circuit.

[0255] In the A-type switching circuit, when the left hand does not touch the key, the optocoupler in the optocoupler group corresponding to the key in the right channel switching circuit is in the on state. When the right hand presses the key, the conductive rubber covers the carbon film contact, and the optocoupler in the optocoupler group corresponding to the right channel will form a current loop and be activated.

[0256] When the fingers of both hands press different keys at the same time, thanks to AQY412EH, no current loop will be formed between the left and right channel optocoupler groups corresponding to the same key, and all will be activated, thus ensuring the independence of the sound source.

[0257] In the left or right channel switching circuit, one end of each optocoupler output is connected to the carbon film contact, and the other end is connected to the corresponding pin of the sound source chip. After the relevant optocoupler group is turned on by pressing the key, the corresponding pin of the relevant sound source chip will be turned on, and two-channel stereo sound can be played.

[0258] Figure 8 This is a structural diagram of the old AB combination switch circuit of the basic version of the electronic keyboard instrument

[0259] In the figure, AB201 is the conductor keyboard. AB202 is the carbon film contact in Area A. AB203 is the carbon film contact in Area C. AB204 is the carbon film contact in Area B. AB205 is the left channel conductor glove. AB206 is the wire input terminal on the conductor glove. AB207 is the left channel DC power supply. AB208 is the first optocoupler for the left channel. AB209 is the second optocoupler for the left channel. AB210 is the third optocoupler for the left channel. AB211 is the left channel audio source chip. AB212 is the pin in Area A of the left channel audio source chip. AB213 is the pin in Area C of the left channel audio source chip. AB214 is the pin in Area B of the left channel audio source chip. AB215 is the right channel DC power supply. AB216 is a directional diode. AB217 is the first optocoupler for the right channel. AB218 is the second optocoupler for the right channel. AB219 is the third optocoupler for the right channel. AB220 is an optocoupler normally closed solid-state relay. AB221 is the right channel audio source chip. AB222 is the right channel audio source chip's Area A pin. AB223 is the right channel audio source chip's Area C pin. AB224 is the right channel audio source chip's Area B pin.

[0260] In the implementation of the basic version of the old AB combination switch circuit:

[0261] (1) Two or two groups of relatively independent sound source chips are used, corresponding to the left hand and right hand playing the keyboard instrument respectively, and the two or two groups of the sound source chips share a layer of conductor keys AB201 and carbon film contacts under the keys.

[0262] (2) Taking a dual-velocity-sensitive electronic keyboard instrument as an example, the carbon film contacts under the keys are divided into relatively independent carbon film contacts in area A AB202, relatively independent common carbon film contacts in area C AB203, and relatively independent carbon film contacts in area B AB204. Among them, the carbon film contacts in area C are common carbon film contacts, and the carbon film contacts in areas A and B are non-common carbon film contacts.

[0263] (3) Two switch circuits corresponding to the left and right channels are set between the carbon film contacts and the two sound source chips, and each switch circuit includes a DC power supply and an optocoupler group that is the same as the number of piano keys.

[0264] (4) In the left and right channel switching circuits, each optocoupler group in each switching circuit includes a first optocoupler corresponding to the carbon film contact in area A below the keyboard, a second optocoupler corresponding to the carbon film contact in area C below the keyboard, and a third optocoupler corresponding to the carbon film contact in area B below the keyboard.

[0265] (5) The positive input terminals of the first optocoupler AB208, the second optocoupler AB209, and the third optocoupler AB210 in each optocoupler group of the left channel switching circuit are directly connected to the positive wire of the left channel DC power supply AB207, and the negative input terminals of these three optocouplers are connected to the conductor keyboard AB201.

[0266] (6) The left channel switching circuit uses a conductor keyboard AB201 and a conductor glove AB205. The negative wire of the left channel DC power supply AB207 is connected to the wire input terminal AB206 on the left hand conductor glove AB205.

[0267] (6) In the right channel switching circuit, the positive electrode wire of the DC power supply AB215 is connected to the positive electrode of the output terminal of the optocoupler normally closed solid-state relay AB220, and the negative electrode of the output terminal of the optocoupler normally closed solid-state relay AB220 is connected to the positive electrodes of the input terminals of the first optocoupler AB217, the second optocoupler AB218 and the third optocoupler AB219 in the corresponding optocoupler group. The negative electrodes of the input terminals of the three optocouplers are combined and connected to the negative electrode wire of the left channel DC power supply AB207 through the directional diode AB216.

[0268] (7) Optocoupler normally closed solid-state relay can be AQY412EH. The optocoupler normally closed solid-state relay is controlled by the left channel switch circuit. Its positive input terminal is connected to the positive wire of the left channel DC power supply AB207, and its negative input terminal is connected to the corresponding conductor key AB201.

[0269] (8) In the left and right channel switching circuits, the negative output terminal of the first optocoupler in each optocoupler group is connected to the carbon film contact AB202 in area A under the corresponding key, the positive output terminal of the second optocoupler is connected to the common carbon film contact AB203 in area C under the corresponding key, and the negative output terminal of the third optocoupler is connected to the carbon film contact AB204 in area B under the corresponding key.

[0270] (9) In each optocoupler group in the left channel switch circuit, the positive output terminal of the first optocoupler AB208 and the positive output terminals of the first optocouplers AB208 in other optocoupler groups are matrix-synthesized according to the matrix keying rule of a traditional electronic keyboard instrument, and then connected to the corresponding pin in the A-zone pin AB212 of the left channel sound source chip AB211;

[0271] The negative output pin of the second optocoupler AB209 and the negative output pins of the second optocouplers AB209 in other optocoupler groups are matrix-synthesized using the matrix keystroke rules of a traditional electronic keyboard instrument, and then connected to the corresponding pin in the C-zone pin AB213 of the left channel sound source chip AB211;

[0272] The positive output terminal of the third optocoupler AB210 and the positive output terminal pins of the third optocouplers AB210 in other optocoupler groups are matrix synthesized according to the matrix key rules of traditional electronic keyboard instruments, and then connected to the corresponding pins in the B area pins AB214 in the left channel sound source chip AB211.

[0273] (10) In each optocoupler group in the right channel switch circuit, the positive output terminal of the first optocoupler AB217 and the positive output terminals of the first optocouplers AB217 in other optocoupler groups are matrix-synthesized according to the matrix keying rule of a traditional electronic keyboard instrument, and then connected to the corresponding pin in the A-zone pin AB222 of the right channel sound source chip AB221;

[0274] The negative output pin of the second optocoupler AB218 and the negative output pin of the second optocoupler AB218 in other optocoupler groups are matrix-synthesized using the matrix keying rules of a traditional electronic keyboard instrument, and then connected to the corresponding pin in the C-zone pin AB223 of the right channel sound source chip AB221;

[0275] The positive output terminal of the third optocoupler AB219 and the positive output terminal pins of the third optocouplers AB219 in other optocoupler groups are matrix synthesized according to the matrix key rules of traditional electronic keyboard instruments, and then connected to the corresponding pins in the B area pins AB224 in the right channel sound source chip AB221.

[0276] Specific embodiment 9: Upgraded new AB combination switch circuit

[0277] In the left-channel switching circuit, the positive input terminal of each optocoupler in the optocoupler group is connected one-to-one to different partitions of relatively independent non-common carbon film contacts under the corresponding conductor key, and the common carbon film contact is connected to the positive wire of the DC power supply; the negative input terminals of all optocouplers in the optocoupler group are combined together and connected to the corresponding conductor keys; the negative wire of the DC power supply serves as the control line of the left-channel switching circuit and is connected to the wire input terminal on the conductor glove.

[0278] In the right channel switching circuit, the positive input terminal of each optocoupler in the optocoupler group is connected one-to-one to different partitions of the relatively independent non-common carbon film contacts under the corresponding conductor key, and the negative input terminals of all optocouplers in the optocoupler group are combined together and connected to the positive output terminal of a corresponding optocoupler normally closed solid-state relay, and the negative output terminal of the corresponding optocoupler normally closed solid-state relay is connected to the negative wire of the DC power supply.

[0279] The positive input terminal of the optocoupler normally closed solid-state relay is connected to the positive wire of the DC power supply; the negative input terminal of the optocoupler normally closed solid-state relay is connected to the corresponding conductor key.

[0280] In each switching circuit, the positive and negative output pins of each optocoupler in the optocoupler group are respectively combined with the same output pins of the optocouplers at the same position in other optocoupler groups in the same circuit, using the matrix key rules of traditional electronic keyboard instruments, and then connected to the corresponding pins of the relevant sound source chip.

[0281] Working principle of the upgraded new AB combination switch circuit:

[0282] The upgraded new AB combination switch circuit described above includes an A-type switch circuit corresponding to the right channel and a B-type switch circuit corresponding to the left channel.

[0283] For the rest of the content, please refer to the working principle of the basic version of the new AB combination switch circuit.

[0284] Figure 9 This is the structural diagram of the new AB combination switch circuit of the upgraded version of the electronic keyboard instrument

[0285] In the figure, AB301 is the conductor keyboard. AB302 is the carbon film contact in area A. AB303 is the carbon film contact in area C. AB304 is the carbon film contact in area B. AB305 is the left channel conductor glove. AB306 is the wire input terminal on the conductor glove. AB307 is the DC power supply. AB308 is the negative wire of the DC power supply. AB309 is the first optocoupler for the left channel. AB310 is the second optocoupler for the left channel. AB311 is the left channel audio source chip. AB312 is the pin in area A of the left channel audio source chip. AB313 is the pin in area C of the left channel audio source chip. AB314 is the pin in area B of the left channel audio source chip. AB315 is the first optocoupler for the right channel. AB316 is the second optocoupler for the right channel. AB317 is the normally closed solid-state relay for the right channel optocoupler. AB318 is the right channel audio source chip. AB319 is the pin for the right channel audio source chip in Area A. AB320 is the pin for the right channel audio source chip in Area C. AB321 is the pin for the right channel audio source chip in Area B.

[0286] In the implementation of the upgraded new AB combination switch circuit:

[0287] (1) Two or two groups of relatively independent sound source chips are used, corresponding to the left hand and the right hand playing the keyboard instrument respectively. The two or two groups of relatively independent sound source chips share a layer of conductor keys AB301 and carbon film contacts under the keys.

[0288] (2) Taking a dual-velocity-sensitive electronic keyboard instrument as an example, the carbon film contacts under the keys include relatively independent carbon film contacts in area A AB302, relatively independent carbon film contacts in area C AB303, and relatively independent carbon film contacts in area B AB304. Among them, the carbon film contacts in area C are common carbon film contacts, and the carbon film contacts in areas A and B are non-common carbon film contacts.

[0289] (3) A left-channel switching circuit is provided between the keys and the carbon film contacts underneath them and the left-channel sound source chip AB311, and a right-channel switching circuit is provided between the keys and the right-channel sound source chip AB318. Each switching circuit includes a set of optocouplers equal to the number of keys, and the two switching circuits share a DC power supply AB307.

[0290] (4) In the left and right channel switching circuits, each optocoupler group in each switching circuit includes a first optocoupler corresponding to the carbon film contacts in area A and area C below the keyboard and a second optocoupler corresponding to the carbon film contacts in area B and area C below the keyboard.

[0291] (5) In the left channel switch circuit, the positive wire of the DC power supply AB307 is connected to the common carbon film contact AB303 in area C, the carbon film contact AB302 in area A and the carbon film contact AB304 in area B are connected to the positive input terminals of the first optocoupler AB309 and the second optocoupler AB310 respectively, and the negative input terminals of the first optocoupler AB309 and the second optocoupler AB310 are connected to the corresponding conductor keyboard AB301.

[0292] (6) The negative wire of the DC power supply AB307 serves as the switch circuit control line and is connected to the wire input terminal AB306 on the conductor glove AB305.

[0293] (7) In the right channel switch circuit, the positive lead of the DC power supply AB307 is connected to the common carbon film contact AB303 in area C, the carbon film contact AB302 in area A and the carbon film contact AB304 in area B are connected to the positive input terminals of the first optocoupler AB315 and the second optocoupler AB316 respectively, the negative input terminals of the first optocoupler AB315 and the second optocoupler AB316 are connected to the positive output terminal of the optocoupler normally closed solid-state relay AB317, and the negative output terminal of the optocoupler normally closed solid-state relay AB317 is connected to the negative lead of the DC power supply AB307.

[0294] (8) The optocoupler normally closed solid-state relay AB317 is controlled by the left channel switching circuit. Its positive input terminal is connected to the positive wire of the DC power supply AB307, and its negative input terminal is connected to the conductor keyboard AB301. The optocoupler normally closed solid-state relay can be AQY412EH.

[0295] (9) In the left channel optocoupler group, the positive output pin of the first optocoupler AB309 and the positive output pin of the first optocoupler AB309 in other optocoupler groups are matrix-synthesized according to the matrix key rules of a traditional electronic keyboard instrument, and then connected to the corresponding pin in the A area pin AB312 of the left channel sound source chip; the negative output pin of the first optocoupler AB309 and the negative output pin of the first optocoupler AB309 in other optocoupler groups are matrix-synthesized according to the matrix key rules of a traditional electronic keyboard instrument, and then connected to the corresponding pin in the C area pin AB313 of the left channel sound source chip.

[0296] (10) In the left channel optocoupler group, the positive output pin of the second optocoupler AB310 and the positive output pin of the second optocoupler AB310 in other optocoupler groups are matrix-synthesized according to the matrix key rules of a traditional electronic keyboard instrument, and then connected to the corresponding pin in the B area pin AB314 in the left channel sound source chip AB311; the negative output pin of the second optocoupler AB310 and the negative output pin of the second optocoupler AB310 in other optocoupler groups are matrix-synthesized according to the matrix key rules of a traditional electronic keyboard instrument, and then connected to the corresponding pin in the C area pin AB313 in the left channel sound source chip AB311.

[0297] (11) In the right channel optocoupler group, the positive output pin of the first optocoupler AB315 and the positive output pin of the first optocoupler AB315 in other optocoupler groups are matrix-synthesized according to the matrix key rules of a traditional electronic keyboard instrument, and then connected to the corresponding pin in the A area pin AB319 of the right channel sound source chip AB318; the negative output pin of the first optocoupler AB315 and the negative output pin of the first optocoupler AB315 in other optocoupler groups are matrix-synthesized according to the matrix key rules of a traditional electronic keyboard instrument, and then connected to the corresponding pin in the C area pin AB320 of the right channel sound source chip AB318.

[0298] (12) In the right channel optocoupler group, the positive output pin of the second optocoupler AB316 and the positive output pin of the second optocoupler AB316 in other optocoupler groups are matrix-synthesized according to the matrix key rules of traditional electronic keyboard instruments, and then connected to the corresponding pin in the B area pin AB321 in the right channel sound source chip AB318; the negative output pin of the second optocoupler AB316 and the negative output pin of the second optocoupler AB316 in other optocoupler groups are matrix-synthesized according to the matrix key rules of traditional electronic keyboard instruments, and then connected to the corresponding pin in the C area pin AB320 in the right channel sound source chip AB318.

[0299] Specific embodiment 10: Upgraded old AB combination switch circuit

[0300] In the left channel switching circuit, the positive input terminals of all the optocouplers in each optocoupler group are combined together and connected to the positive wire of the DC power supply; the negative input terminals of all the optocouplers in each optocoupler group are combined together and connected to the corresponding conductor keys; the negative wire of the DC power supply serves as the control line of the left channel switching circuit and is connected to the wire input terminal on the conductor glove.

[0301] In the right channel switching circuit, the positive input terminals of all the optocouplers in each optocoupler group are combined together and connected to the negative output terminal of the corresponding optocoupler normally closed solid-state relay; the positive output terminal of the corresponding optocoupler normally closed solid-state relay is connected to the positive wire of the DC power supply; the negative input terminals of all the optocouplers in each optocoupler group are combined together and connected to the negative wire of the DC power supply.

[0302] The positive input terminal of the optocoupler normally closed solid-state relay is connected to the positive wire of the DC power supply; the negative input terminal of the optocoupler normally closed solid-state relay is connected to the corresponding conductor key.

[0303] In each switching circuit, one pin of each optocoupler output end in the optocoupler group is connected to the corresponding carbon film contact end wire; another pin of each optocoupler output end in the optocoupler group is matrix synthesized with the same output end pin of the optocoupler at the same position in other optocoupler groups in the same circuit according to the matrix key rules of traditional electronic keyboard instruments, and then connected to the corresponding pin of the relevant sound source chip.

[0304] Working principle of the upgraded old AB combination switch circuit:

[0305] The upgraded version of the old AB combination switch circuit described above includes an A-type switch circuit corresponding to the right channel and a B-type switch circuit corresponding to the left channel.

[0306] For the rest of the content, please refer to the working principle of the basic version of the old AB combination switch circuit.

[0307] Figure 10 This is a schematic diagram of the structure of the old AB combination switch circuit of the upgraded version of the electronic keyboard instrument

[0308] In the figure, AB401 is the conductor keyboard. AB402 is the carbon film contact in Area A. AB403 is the carbon film contact in Area C. AB404 is the carbon film contact in Area B. AB405 is the left channel conductor glove. AB406 is the wire input terminal on the conductor glove. AB407 is the DC power supply. AB408 is the negative wire of the DC power supply. AB409 is the first optocoupler for the left channel. AB410 is the second optocoupler for the left channel. AB411 is the third optocoupler for the left channel. AB412 is the left channel audio source chip. AB413 is the pin in Area A of the left channel audio source chip. AB414 is the pin in Area C of the left channel audio source chip. AB415 is the pin in Area B of the left channel audio source chip. AB416 is the first optocoupler for the right channel. AB417 is the second optocoupler for the right channel. AB418 is the third optocoupler for the right channel. AB419 is the right channel optocoupler normally closed solid-state relay. AB420 is the right channel audio source chip. AB421 is the right channel audio source chip's Area A pin. AB422 is the right channel audio source chip's Area C pin. AB423 is the right channel audio source chip's Area B pin.

[0309] In the implementation of the upgraded old AB combination switch circuit:

[0310] (1) Two or two groups of relatively independent sound source chips are used, corresponding to the left hand and right hand playing the keyboard instrument respectively. The two sound source chips share a layer of conductor keys AB401 and carbon film contacts under the keys.

[0311] (2) Taking a dual-velocity-sensitive electronic keyboard instrument as an example, the carbon film contacts under the keys are divided into relatively independent carbon film contacts in area A AB402, relatively independent carbon film contacts in area C AB403, and relatively independent carbon film contacts in area B AB404. Among them, the carbon film contacts in area C are common carbon film contacts, and the carbon film contacts in areas A and B are non-common carbon film contacts.

[0312] (3) A left-channel switching circuit is provided between the keys and the carbon film contacts underneath them and the left-channel sound source chip AB412, and a right-channel switching circuit is provided between the keys and the right-channel sound source chip AB420. Each switching circuit includes a set of optocouplers equal to the number of keys, and the two switching circuits share a DC power supply AB407.

[0313] (4) In the left and right channel switching circuits, each optocoupler group in each switching circuit includes a first optocoupler corresponding to the carbon film contact in area A below the keyboard, a second optocoupler corresponding to the carbon film contact in area C below the keyboard, and a third optocoupler corresponding to the carbon film contact in area B below the keyboard.

[0314] (5) In each optocoupler group of the left channel switching circuit, the positive input terminals of the first optocoupler AB409, the second optocoupler AB410, and the third optocoupler AB411 are directly connected to the positive wire of the DC power supply AB407, and the negative input terminals of these three optocouplers are connected to the conductor keyboard AB401.

[0315] (6) The left channel switching circuit uses a conductor keyboard AB401. The negative wire AB408 of the DC power supply AB407 serves as the switching circuit control line and is connected to the wire input terminal AB406 on the conductor glove AB405.

[0316] (7) In each optocoupler group of the right channel switching circuit, the positive electrode wire of the DC power supply AB407 is connected to the positive electrode of the output terminal of each optocoupler normally closed solid-state relay AB419, and the negative electrode of the output terminal of the optocoupler normally closed solid-state relay AB419 is connected to the positive electrode of the input terminal of the first optocoupler AB416, the second optocoupler AB417 and the third optocoupler AB418 in the corresponding optocoupler group, and the negative electrode of the input terminal of the three optocouplers is connected to the negative electrode wire of the DC power supply AB407.

[0317] (8) Optocoupler normally closed solid state relay AB419 can be selected from AQY412EH. Optocoupler normally closed solid state relay AB419 is controlled by the left channel switch circuit. Its positive input terminal is connected to the positive wire of DC power supply AB407, and its negative input terminal is connected to the corresponding conductor keyboard AB401.

[0318] (9) In each optocoupler group of the left and right channel switching circuits, the negative electrode of the output terminal of the first optocoupler is connected to the carbon film contact AB402 in area A under the corresponding key, the positive electrode of the output terminal of the second optocoupler is connected to the common carbon film contact AB403 in area C under the corresponding key, and the negative electrode of the output terminal of the third optocoupler is connected to the carbon film contact AB404 in area B under the corresponding key.

[0319] (9) In each optocoupler group in the left channel switch circuit, the positive output terminal of the first optocoupler AB409 and the positive output terminals of the first optocouplers AB409 in other optocoupler groups are matrix-synthesized according to the matrix keying rule of a traditional electronic keyboard instrument, and then connected to the corresponding pin in the A-zone pin AB413 of the left channel sound source chip AB412;

[0320] The negative output pin of the second optocoupler AB410 and the negative output pins of the second optocouplers AB410 in other optocoupler groups are matrix-synthesized using the matrix keying rules of a traditional electronic keyboard instrument, and then connected to the corresponding pin in the C-zone pin AB414 of the left channel sound source chip AB412;

[0321] The positive output terminal of the third optocoupler AB411 and the positive output terminal pins of the third optocouplers AB411 in other optocoupler groups are matrix synthesized according to the matrix key rules of traditional electronic keyboard instruments, and then connected to the corresponding pins in the B area pins AB415 in the left channel sound source chip AB412.

[0322] (10) In each optocoupler group in the right channel switch circuit, the positive output terminal of the first optocoupler AB416 and the positive output terminals of the first optocouplers AB416 in other optocoupler groups are matrix-synthesized according to the matrix keying rule of a traditional electronic keyboard instrument, and then connected to the corresponding pin in the A-zone pin AB421 of the right channel sound source chip AB420;

[0323] The negative output pin of the second optocoupler AB417 and the negative output pin of the second optocoupler AB417 in other optocoupler groups are matrix-synthesized using the matrix keying rules of a traditional electronic keyboard instrument, and then connected to the corresponding pin in the C-zone pin AB422 of the right channel sound source chip AB420;

[0324] The positive output terminal of the third optocoupler AB418 and the positive output terminal pins of the third optocouplers AB418 in other optocoupler groups are matrix synthesized according to the matrix key rules of traditional electronic keyboard instruments, and then connected to the corresponding pins in the B area pins AB423 in the right channel sound source chip AB420.

[0325] Specific embodiment 11: New AC combination switch circuit

[0326] In the left-channel switching circuit, the positive input terminal of each optocoupler in each optocoupler group is connected one-to-one to different partitions of relatively independent non-common carbon film contacts under the corresponding conductor key; the common carbon film contact is connected to the VCC pin of the single-chip microcomputer circuit; the negative input terminals of all optocouplers in each optocoupler group are combined and connected to the corresponding output terminal of the single-chip microcomputer circuit; the high and low level control lines of the single-chip microcomputer circuit serve as control lines of the switching circuit and are connected to the wire input terminal on the left-channel conductor glove.

[0327] In the right channel switching circuit, the positive input terminal of each optocoupler in each optocoupler group is connected one-to-one to different partitions of relatively independent non-common carbon film contacts under the corresponding conductor key; the common carbon film contact is connected to the VCC pin of the microcontroller circuit; the negative input terminals of all optocouplers in each optocoupler group are combined together and connected to the positive output terminal of the corresponding optocoupler normally closed solid-state relay, and the negative output terminal of the corresponding optocoupler normally closed solid-state relay is connected to the GND pin of the microcontroller circuit.

[0328] The positive input terminal of the optocoupler normally closed solid-state relay is connected to the VCC pin of the single-chip microcomputer circuit; the negative input terminal of the optocoupler normally closed solid-state relay is connected to the corresponding output terminal of the single-chip microcomputer circuit.

[0329] In each switching circuit, the positive and negative output pins of each optocoupler in the optocoupler group are respectively combined with the same output pins of the optocouplers at the same position in other optocoupler groups in the same circuit, using the matrix key rules of traditional electronic keyboard instruments, and then connected to the corresponding pins of the relevant sound source chip.

[0330] Working principle of the new AC combination switch circuit:

[0331] The new AC combination switch circuit described above includes an A-type switch circuit corresponding to the right channel and a C-type switch circuit corresponding to the left channel.

[0332] For the rest of the content, please refer to the working principle of the basic version of the new AB combination switch circuit.

[0333] Figure 11 This is a schematic diagram of the structure of the new AC combination switch circuit of the electronic keyboard instrument

[0334] In the figure, AC101 is the conductor keyboard. AC102 is the carbon film contact in area A. AC103 is the carbon film contact in area B. AC104 is the carbon film contact in area C. AC105 is the common carbon film contact in area D. AC106 is the left channel conductor glove. AC107 is the wire input terminal on the conductor glove. AC108 is the microcontroller circuit. AC109 is the high and low level control line of the microcontroller circuit. AC110 is the input I / O port of the microcontroller circuit. AC111 is the output I / O port of the microcontroller circuit. AC112 is the VCC pin of the microcontroller circuit. AC113 is the GND pin of the microcontroller circuit. AC114 is the first optocoupler of the left channel. AC115 is the second optocoupler of the left channel. AC116 is the third optocoupler of the left channel. AC117 is the left channel audio source chip. AC118 is the pin of the left channel audio source chip in area A. AC119 is the pin of the left channel audio source chip in area B. AC120 is a pin in Area C of the left channel audio source chip. AC121 is a pin in Area D of the left channel audio source chip. AC122 is the first optocoupler for the right channel. AC123 is the second optocoupler for the right channel. AC124 is the third optocoupler for the right channel. AC125 is a normally closed solid-state relay for the right channel optocoupler. AC126 is the right channel audio source chip. AC127 is a pin in Area A of the right channel audio source chip. AC128 is a pin in Area B of the right channel audio source chip. AC129 is a pin in Area C of the right channel audio source chip. AC130 is a pin in Area D of the right channel audio source chip.

[0335] In the implementation of the new AC combination switch circuit:

[0336] (1) Two or two groups of relatively independent sound source chips are used, corresponding to the left hand and the right hand playing the keyboard instrument respectively. The two or two groups of relatively independent sound source chips share a layer of conductor keys AC101 and carbon film contacts under the keys.

[0337] (2) Taking a three-force-sensitive electronic keyboard instrument as an example, the carbon film contacts under the keys include relatively independent carbon film contacts in area A AC102, relatively independent carbon film contacts in area B AC103, relatively independent carbon film contacts in area C AC104, and relatively independent carbon film contacts in area D AC105. Among them, the carbon film contacts in area D are common carbon film contacts, and the carbon film contacts in areas A, B, and C are non-common carbon film contacts.

[0338] (3) A left-channel switching circuit is provided between the carbon film contact and the left-channel sound source chip AC117, and a right-channel switching circuit is provided between the carbon film contact and the right-channel sound source chip AC126. Both the left-channel switching circuit and the right-channel switching circuit include optocoupler groups corresponding to the number of piano keys, and the left and right-channel switching circuits share a single-chip microcontroller circuit, AC108.

[0339] (4) In the left and right channel switching circuits, each optocoupler group in each switching circuit includes a first optocoupler corresponding to the carbon film contacts in areas A and D below the keyboard, a second optocoupler corresponding to the carbon film contacts in areas B and D below the keyboard, and a third optocoupler corresponding to the carbon film contacts in areas C and D below the keyboard.

[0340] (5) In the left channel switch circuit, the VCC pin AC112 of the single-chip microcomputer circuit AC108 is connected to the common carbon film contact AC105 of all D areas, the carbon film contact AC102 of the A area is connected to the positive input terminal of the first optocoupler AC114, the carbon film contact AC103 of the B area is connected to the positive input terminal of the second optocoupler AC115, and the carbon film contact AC104 of the C area is connected to the positive input terminal of the third optocoupler AC116. The negative input terminals of the first, second and third optocouplers are connected to the corresponding single-chip microcomputer output IO port AC110, and the single-chip microcomputer input IO port AC109 is connected to the corresponding conductor keyboard AC101.

[0341] (6) The left channel switching circuit uses the conductor keyboard AC101. The high and low level control lines AC109 of the single chip microcomputer circuit AC108 serve as the switching circuit control lines and are connected to the wire input terminal AC107 on the conductor glove AC106.

[0342] (7) In the right channel switch circuit, the VCC pin AC112 of the single-chip microcomputer circuit AC108 is connected to the common carbon film contact AC105 in the D area, the carbon film contact AC102 in the A area is connected to the positive input terminal of the first optocoupler AC122 of the right channel, the carbon film contact AC103 in the B area is connected to the positive input terminal of the second optocoupler AC123 of the right channel, and the carbon film contact AC104 in the C area is connected to the positive input terminal of the third optocoupler AC124 of the right channel. The negative input terminals of the first, second and third optocouplers are connected to the positive output terminal of the optocoupler normally closed solid-state relay AC125, and the negative output terminal of the optocoupler normally closed solid-state relay AC125 is connected to the gnd pin AC113 of the single-chip microcomputer circuit.

[0343] (8) The optocoupler normally closed solid-state relay AC125 is controlled by the left channel switch circuit, and its positive input terminal is connected to the VCC pin AC112 of the microcontroller circuit, and its negative input terminal is connected to the output IO port AC111 corresponding to the microcontroller circuit.

[0344] (9) In the left channel optocoupler group, the positive output pin of the first optocoupler AC114 and the positive output pin of the first optocoupler AC114 in other optocoupler groups are matrix-synthesized according to the matrix key rules of a traditional electronic keyboard instrument, and then connected to the corresponding pin in the A-zone pin AC118 of the left channel sound source chip AC117; the negative output pin of the first optocoupler AC114 and the negative output pin of the first optocoupler AC114 in other optocoupler groups are matrix-synthesized according to the matrix key rules of a traditional electronic keyboard instrument, and then connected to the corresponding pin in the D-zone pin AC121 of the left channel sound source chip AC117.

[0345] The positive output pin of the second optocoupler AC115 and the positive output pin of the second optocoupler AC115 in other optocoupler groups are matrix-synthesized according to the matrix key pressing rules of a traditional electronic keyboard instrument, and then connected to the corresponding pin in the B area pin AC119 of the left channel sound source chip AC117; the negative output pin of the second optocoupler AC115 and the negative output pin of the second optocoupler AC115 in other optocoupler groups are matrix-synthesized according to the matrix key pressing rules of a traditional electronic keyboard instrument, and then connected to the corresponding pin in the D area pin AC121 of the left channel sound source chip AC117.

[0346] The positive output pin of the third optocoupler AC116 and the positive output pin of the third optocoupler AC116 in other optocoupler groups are matrix-synthesized according to the matrix key pressing rules of a traditional electronic keyboard instrument, and then connected to the corresponding pin in the C area pin AC120 in the left channel sound source chip AC117; the negative output pin of the third optocoupler AC116 and the negative output pin of the third optocoupler AC116 in other optocoupler groups are matrix-synthesized according to the matrix key pressing rules of a traditional electronic keyboard instrument, and then connected to the corresponding pin in the D area pin AC121 in the left channel sound source chip AC117.

[0347] (10) In the right channel optocoupler group, the positive output pin of the first optocoupler AC122 and the positive output pin of the first optocoupler AC122 in other optocoupler groups are matrix-synthesized according to the matrix key rules of a traditional electronic keyboard instrument, and then connected to the corresponding pin in the A-zone pin AC127 of the right channel sound source chip AC126; the negative output pin of the first optocoupler AC122 and the negative output pin of the first optocoupler AC122 in other optocoupler groups are matrix-synthesized according to the matrix key rules of a traditional electronic keyboard instrument, and then connected to the corresponding pin in the D-zone pin AC130 of the right channel sound source chip AC126.

[0348] The positive output pin of the second optocoupler AC123 and the positive output pin of the second optocoupler AC123 in other optocoupler groups are matrix-synthesized according to the matrix key pressing rules of a traditional electronic keyboard instrument, and then connected to the corresponding pin in the B area pin AC128 of the right channel sound source chip AC126; the negative output pin of the second optocoupler AC123 and the negative output pin of the second optocoupler AC123 in other optocoupler groups are matrix-synthesized according to the matrix key pressing rules of a traditional electronic keyboard instrument, and then connected to the corresponding pin in the D area pin AC130 of the right channel sound source chip AC126.

[0349] The positive output pin of the third optocoupler AC124 and the positive output pin of the third optocoupler AC124 in other optocoupler groups are matrix-synthesized according to the matrix key pressing rules of a traditional electronic keyboard instrument, and then connected to the corresponding pin in the C area pin AC129 of the right channel sound source chip AC126; the negative output pin of the third optocoupler AC124 and the negative output pin of the third optocoupler AC124 in other optocoupler groups are matrix-synthesized according to the matrix key pressing rules of a traditional electronic keyboard instrument, and then connected to the corresponding pin in the D area pin AC130 of the right channel sound source chip AC126.

[0350] Specific embodiment 12: old AC combination switch circuit

[0351] In the left channel switching circuit, the positive input terminals of all optocouplers in each optocoupler group are combined together and connected to the VCC pin of the single-chip microcomputer circuit; the negative input terminals of all optocouplers in each optocoupler group are combined together and connected to the corresponding output terminals of the single-chip microcomputer circuit; the high and low level control lines of the single-chip microcomputer circuit serve as control lines of the switching circuit and are connected to the wire input terminals on the left channel conductor glove.

[0352] In the right channel switching circuit, the positive poles of the input ends of all optocouplers in each optocoupler group are combined together and connected to the negative pole of the output end of the corresponding optocoupler normally closed solid-state relay; the positive pole of the output end of the corresponding optocoupler normally closed solid-state relay is connected to the VCC pin of the microcontroller circuit; the negative poles of the input ends of all optocouplers in each optocoupler group are combined together and connected to the GND pin of the microcontroller circuit.

[0353] The positive input terminal of the optocoupler normally closed solid-state relay is connected to the VCC pin of the single-chip microcomputer circuit, and the negative input terminal of the optocoupler normally closed solid-state relay is connected to the corresponding output terminal of the single-chip microcomputer circuit.

[0354] In each switching circuit, one pin of each optocoupler output end in the optocoupler group is connected to the corresponding carbon film contact end wire; another pin of each optocoupler output end in the optocoupler group is matrix synthesized with the same output end pin of the optocoupler at the same position in other optocoupler groups in the same circuit according to the matrix key rules of traditional electronic keyboard instruments, and then connected to the corresponding pin of the relevant sound source chip.

[0355] Working principle of the old AC combination switch circuit:

[0356] The conventional AC combination switch circuit mentioned above includes an A-type switch circuit corresponding to the right channel and a C-type switch circuit corresponding to the left channel.

[0357] For the rest of the content, please refer to the working principle of the basic version of the old AB combination switch circuit.

[0358] Figure 12 This is a schematic diagram of the structure of the old AC combination switch circuit of the electronic keyboard instrument

[0359] In the figure, AC201 is the conductor keyboard. AC202 is the carbon film contact in area A. AC203 is the carbon film contact in area B. AC204 is the carbon film contact in area C. AC205 is the carbon film contact in area D. AC206 is the left channel conductor glove. AC207 is the wire input terminal on the conductor glove. AC208 is the microcontroller circuit. AC209 is the microcontroller high and low level control line. AC210 is the microcontroller input I / O port. AC211 is the microcontroller output I / O port. AC212 is the microcontroller VCC pin. AC213 is the microcontroller GND pin. AC214 is the first optocoupler for the left channel. AC215 is the second optocoupler for the left channel. AC216 is the third optocoupler for the left channel. AC217 is the fourth optocoupler for the left channel. AC218 is the left channel audio source chip. AC219 is the pin in area A of the left channel audio source chip. AC220 is the pin in area B of the left channel audio source chip. AC221 is a pin in Area C of the left channel audio source chip. AC22 is a pin in Area D of the left channel audio source chip. AC223 is the first optocoupler for the right channel. AC224 is the second optocoupler for the right channel. AC225 is the third optocoupler for the right channel. AC226 is the fourth optocoupler for the right channel. AC227 is a normally closed solid-state relay for the right channel optocoupler. AC228 is the right channel audio source chip. AC229 is a pin in Area A of the right channel audio source chip. AC230 is a pin in Area B of the right channel audio source chip. AC231 is a pin in Area C of the right channel audio source chip. AC232 is a pin in Area D of the right channel audio source chip.

[0360] In the implementation of the old AC combination switch circuit:

[0361] (1) Two or two groups of relatively independent sound source chips are used, corresponding to the left hand and the right hand playing the keyboard instrument respectively. The two or two groups of relatively independent sound source chips share a layer of conductor keys AC201 and carbon film contacts under the keys.

[0362] (2) In an electronic keyboard instrument with three force sensors, the carbon film contacts under the keys are divided into relatively independent carbon film contacts in area A (AC202), relatively independent carbon film contacts in area B (AC203), relatively independent carbon film contacts in area C (AC204), and relatively independent carbon film contacts in area D (AC205). The carbon film contacts in area D are common carbon film contacts, while the carbon film contacts in areas A, B, and C are non-common carbon film contacts.

[0363] (3) Two switch circuits corresponding to the left and right channels are set between the carbon film contacts and two or two groups of sound source chips. The left and right channel switch circuits both include optocoupler groups that are the same number as the piano keys. The left and right channel switch circuits share a single-chip microcomputer circuit AC208.

[0364] (4) In the left and right channel switching circuits, each optocoupler group in each switching circuit includes a first optocoupler corresponding to the carbon film contact in area A below the keyboard, a second optocoupler corresponding to the carbon film contact in area B below the keyboard, a third optocoupler corresponding to the carbon film contact in area C below the keyboard, and a fourth optocoupler corresponding to the carbon film contact in area D below the keyboard.

[0365] (5) The positive input terminals of the first optocoupler AC214, the second optocoupler AC215, the third optocoupler AC216, and the fourth optocoupler AC217 in each optocoupler group of the left channel switch circuit are connected to the VCC pin AC212 of the single-chip computer circuit AC207, and the negative input terminals of these four optocouplers are connected to the corresponding output IO port AC211 of the single-chip computer circuit AC208.

[0366] (6) The left channel switching circuit uses a conductor keyboard AC201. The high and low level control lines AC209 of the single-chip microcomputer circuit AC208 serve as the switching circuit control lines and are connected to the wire input terminal AB207 on the conductor glove AB206. Each conductor keyboard AC201 is connected to the corresponding single-chip microcomputer circuit input IO port AC210 via a wire.

[0367] (7) In the right channel switch circuit, the positive output terminal of the optocoupler normally closed solid-state relay AC227 is connected to the VCC pin AC212 of the single-chip microcomputer circuit AC208, and the negative output terminal of the optocoupler normally closed solid-state relay AC227 is connected to the positive input terminals of the first optocoupler AC223, the second optocoupler AC224, the third optocoupler AC225, and the fourth optocoupler AC226. The negative input terminals of the first optocoupler, the second optocoupler, the third optocoupler, and the fourth optocoupler are connected to the GND pin AC213 of the single-chip microcomputer circuit.

[0368] (8) Optocoupler normally closed solid-state relay AC227 can be AQY412EH. Optocoupler normally closed solid-state relay AC227 is controlled by the left channel switch circuit. Its positive input terminal is connected to the VCC pin AC212 of the single-chip microcomputer circuit AC208, and its negative input terminal is connected to the corresponding output IO port AC211 of the single-chip microcomputer circuit AC208.

[0369] (9) In each optocoupler group of the left and right channel switching circuits, the negative output terminal of the first optocoupler is connected to the carbon film contact AC202 in area A below the corresponding key, the negative output terminal of the second optocoupler is connected to the common carbon film contact AC203 in area B below the corresponding key, the negative output terminal of the third optocoupler is connected to the carbon film contact AC204 in area C below the corresponding key, and the positive output terminal of the fourth optocoupler is connected to the carbon film contact AC205 in area D below the corresponding key.

[0370] (10) In each optocoupler group in the left channel switch circuit, the positive output terminal of the first optocoupler AC214 and the positive output terminals of the first optocoupler AC214 in other optocoupler groups are matrix-synthesized according to the matrix keying rule of a traditional electronic keyboard instrument, and then connected to the corresponding pin in the A-zone pin AC219 of the left channel sound source chip AC218;

[0371] The positive output pin of the second optocoupler AC215 and the positive output pins of the second optocoupler AC215 in other optocoupler groups are matrix-synthesized using the matrix keystroke rules of a traditional electronic keyboard instrument, and then connected to the corresponding pins in the B-zone pins AC220 of the left channel sound source chip AC218;

[0372] The positive output terminal of the third optocoupler AC216 and the positive output terminal pins of the third optocoupler AC216 in other optocoupler groups are matrix synthesized according to the matrix key rules of traditional electronic keyboard instruments, and then connected to the corresponding pins in the C area pin AC221 in the left channel audio source chip AC218.

[0373] The negative output terminal of the fourth optocoupler AC217 and the negative output terminal pins of the fourth optocoupler AC217 in other optocoupler groups are matrix synthesized according to the matrix key rules of traditional electronic keyboard instruments, and then connected to the corresponding pins in the D area pin AC222 in the left channel sound source chip AC218.

[0374] (11) In each optocoupler group in the right channel switch circuit, the positive output terminal of the first optocoupler AC223 and the positive output terminals of the first optocoupler AC223 in other optocoupler groups are matrix-synthesized according to the matrix keying rule of a traditional electronic keyboard instrument, and then connected to the corresponding pin in the A-zone pin AC229 of the right channel sound source chip AC228;

[0375] The positive output pin of the second optocoupler AC224 and the positive output pins of the second optocoupler AC224 in other optocoupler groups are matrix-synthesized using the matrix keystroke rules of a traditional electronic keyboard instrument, and then connected to the corresponding pins in the B-zone pins AC230 of the right channel sound source chip AC228;

[0376] The positive output terminal of the third optocoupler AC225 and the positive output terminal pins of the third optocoupler AC225 in other optocoupler groups are matrix synthesized according to the matrix key rules of traditional electronic keyboard instruments, and then connected to the corresponding pins in the C area pin AC231 in the right channel sound source chip AC228.

[0377] The negative output terminal of the fourth optocoupler AC226 and the negative output terminal pins of the fourth optocoupler AC226 in other optocoupler groups are matrix synthesized according to the matrix key rules of traditional electronic keyboard instruments, and then connected to the corresponding pins in the D area pin AC232 in the right channel audio source chip AC228.

[0378] Specific embodiment 13: Technical solution of timbre superposition stereo

[0379] In a two-channel or multi-channel switching circuit, in each of the optocoupler groups in each of the switching circuits, there are two or more optocouplers corresponding to different partitions of the non-common carbon film contacts under the keyboard, which respectively control the corresponding pins in the relevant two or more sound source chips, thereby realizing the superposition of stereo sounds of electronic keyboard instruments.

[0380] Tone superposition stereo is applicable to AA combination partition fixed structure, AA combination partition adjustable structure, new BB combination structure, new CC combination structure, new AB combination structure, and new AC combination structure.

[0381] How does Tone Stacking Stereo work?

[0382] Based on the original AA combination partition fixed structure, AA combination partition adjustable structure, new BB combination structure, new CC combination structure, new AB combination structure, and new AC combination structure switching circuits, in each switching circuit, by doubling the number of optocouplers in the optocoupler group, two or more relatively independent sound source chips can be controlled simultaneously, thereby achieving stereo sound superposition.

[0383] Figure 13 This is a schematic diagram of the structure of the electronic keyboard instrument sound superimposed stereo dual sound

[0384] In the figure, AA301 is the carbon film contact in area A. AA302 is the carbon film contact in area C. AA303 is the carbon film contact in area B. AA304 is the DC power supply. AA305 is the first optocoupler for the left channel. AA306 is the second optocoupler for the left channel. AA307 is the third optocoupler for the left channel. AA308 is the fourth optocoupler for the left channel. AA309 is the first audio source chip for the left channel. AA310 is the second audio source chip for the left channel. AA311 is the first optocoupler for the right channel. AA312 is the second optocoupler for the right channel. AA313 is the third optocoupler for the right channel. AA314 is the fourth optocoupler for the right channel. AA315 is the first audio source chip for the right channel. AA316 is the second audio source chip for the right channel.

[0385] In the implementation of the timbre superposition stereo:

[0386] (1) Specific implementation method of dual-tone stereo dual-force sensing mode: Taking the AA combination partition fixed structure as an example, in each switch circuit, the optocoupler group corresponding to the same key includes the first optocoupler, the second optocoupler, the third optocoupler and the fourth optocoupler, wherein the first optocoupler and the second optocoupler correspond to one sound source chip, and the third optocoupler and the fourth optocoupler correspond to another sound source chip.

[0387] (2) In the left and right channel switching circuits, the positive poles of the input terminals of all optocouplers are connected to the positive wire of the DC power supply, wherein the negative poles of the input terminals of the first and third optocouplers are connected to the relatively independent carbon film contacts AA301 in the A area under the corresponding keyboard, and the negative poles of the input terminals of the second and fourth optocouplers are connected to the relatively independent carbon film contacts AA303 in the B area under the corresponding keyboard.

[0388] (3) In the left channel switching circuit, the positive output pin of the first optocoupler AA305 in the optocoupler group and the positive output pin of the first optocoupler AA305 in other optocoupler groups are matrix-synthesized according to the matrix key-pressing rule of a traditional electronic keyboard instrument, and then connected to the corresponding pin in the A-zone pin of the first sound source chip AA309 of the left channel; the negative output pin of the first optocoupler AA305 and the negative output pin of the first optocoupler AA305 in other optocoupler groups are matrix-synthesized according to the matrix key-pressing rule of a traditional electronic keyboard instrument, and then connected to the corresponding pin in the C-zone pin of the first sound source chip AA309 of the left channel;

[0389] (3) In the left channel switching circuit, the positive output pin of the second optocoupler AA306 in the optocoupler group and the positive output pin of the second optocoupler AA306 in other optocoupler groups are matrix-synthesized according to the matrix key-pressing rule of a traditional electronic keyboard instrument, and then connected to the corresponding pin in the B area pins of the first sound source chip AA309 of the left channel; the negative output pin of the second optocoupler AA306 and the negative output pin of the second optocoupler AA306 in other optocoupler groups are matrix-synthesized according to the matrix key-pressing rule of a traditional electronic keyboard instrument, and then connected to the corresponding pin in the C area pins of the first sound source chip AA309 of the left channel;

[0390] (4) In the left channel switching circuit, the positive output pin of the third optocoupler AA307 in the optocoupler group and the positive output pin of the third optocoupler AA307 in other optocoupler groups are matrix-synthesized according to the matrix key-pressing rule of a traditional electronic keyboard instrument, and then connected to the corresponding pin in the A zone pins of the second sound source chip AA310 of the left channel; the negative output pin of the third optocoupler AA307 and the negative output pin of the third optocoupler AA307 in other optocoupler groups are matrix-synthesized according to the matrix key-pressing rule of a traditional electronic keyboard instrument, and then connected to the corresponding pin in the C zone pins of the second sound source chip AA310 of the left channel;

[0391] (5) In the left channel switching circuit, the positive output pin of the fourth optocoupler AA308 in the optocoupler group and the positive output pin of the fourth optocoupler AA308 in other optocoupler groups are matrix-synthesized according to the matrix key-pressing rule of a traditional electronic keyboard instrument, and then connected to the corresponding pin in the B area pins of the left channel second sound source chip AA310; the negative output pin of the fourth optocoupler AA308 and the negative output pin of the fourth optocoupler AA308 in other optocoupler groups are matrix-synthesized according to the matrix key-pressing rule of a traditional electronic keyboard instrument, and then connected to the corresponding pin in the C area pins of the left channel second sound source chip AA310;

[0392] (6) In the right channel switching circuit, the positive output pin of the first optocoupler AA311 in the optocoupler group and the positive output pin of the first optocoupler AA311 in other optocoupler groups are matrix-synthesized according to the matrix key rules of a traditional electronic keyboard instrument, and then connected to the corresponding pin in the A area pin of the first sound source chip AA315 of the right channel; the negative output pin of the first optocoupler AA311 and the negative output pin of the first optocoupler AA311 in other optocoupler groups are matrix-synthesized according to the matrix key rules of a traditional electronic keyboard instrument, and then connected to the corresponding pin in the C area pin of the first sound source chip AA315 of the right channel;

[0393] (7) In the right channel switching circuit, the positive output pin of the second optocoupler AA312 in the optocoupler group and the positive output pin of the second optocoupler AA312 in other optocoupler groups are matrix-synthesized according to the matrix key rules of a traditional electronic keyboard instrument, and then connected to the corresponding pin in the B area pins of the first sound source chip AA315 of the right channel; the negative output pin of the second optocoupler AA305 and the negative output pin of the second optocoupler AA206 in other optocoupler groups are matrix-synthesized according to the matrix key rules of a traditional electronic keyboard instrument, and then connected to the corresponding pin in the C area pins of the first sound source chip AA315 of the right channel;

[0394] (8) In the right channel switch circuit, the positive output pin of the third optocoupler AA313 in the optocoupler group and the positive output pin of the third optocoupler AA313 in other optocoupler groups are matrix-synthesized according to the matrix key-pressing rule of a traditional electronic keyboard instrument, and then connected to the corresponding pin in the A zone pin of the second sound source chip AA316 of the right channel; the negative output pin of the third optocoupler AA313 and the negative output pin of the third optocoupler AA313 in other optocoupler groups are matrix-synthesized according to the matrix key-pressing rule of a traditional electronic keyboard instrument, and then connected to the corresponding pin in the C zone pin of the second sound source chip AA316 of the right channel;

[0395] (9) In the right channel switching circuit, the positive output pin of the fourth optocoupler AA314 in the optocoupler group and the positive output pin of the fourth optocoupler AA314 in other optocoupler groups are matrix-synthesized according to the matrix key-pressing rule of a traditional electronic keyboard instrument, and then connected to the corresponding pin in the B area pins of the second sound source chip AA316 of the right channel; the negative output pin of the fourth optocoupler AA314 and the negative output pin of the fourth optocoupler AA314 in other optocoupler groups are matrix-synthesized according to the matrix key-pressing rule of a traditional electronic keyboard instrument, and then connected to the corresponding pin in the C area pins of the second sound source chip AA316 of the right channel;

[0396] (10) In the dual-timbre and triple-timbre structures, in each switch circuit, the number of optocouplers in parallel in the optocoupler group corresponding to each key is different. Dual-timbre requires twice the number of optocouplers in parallel, and triple-timbre requires three times the number of optocouplers in parallel. In addition, the number of optocouplers in the optocoupler group is also different depending on the number of key velocity sensing points.

[0397] Figure 14 This is a diagram showing the connection between the optocoupler in the optocoupler group and the corresponding pins of the relevant audio source chip.

[0398] In the figure, 1 is the optocoupler corresponding to the carbon film contacts in area A. 2 is the optocoupler corresponding to the carbon film contacts in area C. 3 is the optocoupler corresponding to the carbon film contacts in area B. 4 is the audio chip. 5 is the audio chip pin in area A, 6 is the audio chip pin in area C, and 7 is the audio chip pin in area B.

[0399] Figure 15 This is a diagram showing the connection between the optocoupler in the optocoupler group and the corresponding pins of the relevant audio source chip.

[0400] In the figure, 1 is the optocoupler corresponding to the carbon film contacts in areas A and C. 2 is the optocoupler corresponding to the carbon film contacts in areas B and C. 3 is the audio chip. 4 is the audio chip pin in area A, 5 is the audio chip pin in area C, and 6 is the audio chip pin in area B.

[0401] Figure 16 This is a diagram showing the connection between the carbon film contacts under the keys of a traditional electronic keyboard instrument and the corresponding pins of the sound source chip.

[0402] In the figure, 1 is the keyboard of a traditional electronic keyboard instrument. 2 is the carbon film contacts beneath the keys of a traditional electronic keyboard instrument. 3 is the sound source chip of a traditional electronic keyboard instrument. 4 is the carbon film contacts in area A beneath the keys. 5 is the carbon film contacts in area C beneath the keys. 6 is the carbon film contacts in area B beneath the keys. 7 is the pins in area A of the sound source chip. 8 is the pins in area C of the sound source chip. 9 is the pins in area B of the sound source chip.

[0403] above Figure 14This section explains the connection relationship between the audio chip pins and the optocoupler output terminals in the diagrams of the old BB combination switch circuit, the old CC combination switch circuit, the old AB combination switch circuit, and the old AC combination switch circuit.

[0404] above Figure 15 This is an explanation of the connection relationship between the audio source chip pins and the optocoupler output terminals in the attached drawings of the new BB combination switch circuit, the new CC combination switch circuit, the new AB combination switch circuit, the new AC combination switch circuit, the AA combination partition fixed switch circuit, the AA combination partition adjustable switch circuit, and the tone superposition stereo.

[0405] above Figure 16 It is an explanation of the description of the prior art in the background technology.

[0406] For simplicity and convenience, the text uses a fixed format to describe the left and right channels and the positive and negative poles. In actual applications, the names of the left and right channels and the positive and negative poles can be converted to each other. Of course, the corresponding circuit connection relationships also need to be converted accordingly.

[0407] The same and similar parts between the various embodiments in this specification can be referenced to each other, and each embodiment focuses on the differences from other embodiments.

[0408] Professionals may further appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, the above description has generally described the components and steps of each example according to their functions. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professionals and technicians may use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present invention.

[0409] The above description of the disclosed embodiments indicates that the features described in the various embodiments in this specification may be interchanged or combined to enable those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention.

Claims

1. An electronic keyboard musical instrument comprising keys, carbon film contacts beneath the keys, and a sound source chip on a mainboard, characterized in that: The keys are conductor keys; The carbon film contacts are relatively independent; The left and right hands playing the keyboard instrument correspond to one or a group of relatively independent sound source chips respectively; A switch circuit is provided between the conductor keys and the relatively independent carbon film contacts below them and the sound source chips corresponding to the left and right hands respectively; Playing electronic keyboard instruments with conductor keys requires the use of conductor gloves; The left or right hand wearing the conductive glove presses any of the conductive keys to control the corresponding optocoupler group in the related switch circuit, and further control the corresponding pin in the related sound source chip; The switching circuit includes a left channel switching circuit and a right channel switching circuit; The left channel switching circuit and the right channel switching circuit both include independent DC power supplies and optocoupler groups that are the same in number as the piano keys; The current directions of the left channel switching circuit and the right channel switching circuit are opposite; In the left-channel switching circuit, the positive input terminals of all the optocouplers in each optocoupler group are combined and connected to the positive wire of the left-channel DC power supply; the negative input terminals of each optocoupler in each optocoupler group are connected one-to-one to different partitions of relatively independent non-common carbon film contacts under the corresponding conductor key; the common carbon film contacts are connected to the corresponding conductor key; the negative wire of the left-channel DC power supply serves as the control line of the switching circuit and is connected to the wire input terminal on the left-channel conductor glove; In the right channel switching circuit, the negative input terminals of all the optocouplers in each optocoupler group are combined and connected to the negative wire of the right channel DC power supply; the positive input terminal of each optocoupler in each optocoupler group is connected one-to-one to different partitions of relatively independent non-common carbon film contacts under the corresponding conductor key; the common carbon film contacts are connected to the corresponding conductor keys; the positive wire of the right channel DC power supply serves as the control line of the switching circuit and is connected to the wire input terminal on the right channel conductor glove.

2. The electronic keyboard musical instrument according to claim 1, wherein: In the left channel switching circuit, the positive input terminals of all the optocouplers in the optocoupler group are combined together and connected to the positive wire of the left channel DC power supply; the negative input terminals of all the optocouplers in the optocoupler group are combined together and connected to the corresponding conductor keys; the negative wire of the left channel DC power supply serves as the control line of the switching circuit and is connected to the wire input terminal on the left channel conductor glove; In the right channel switching circuit, the negative input terminals of all the optocouplers in the optocoupler group are combined together and connected to the negative wire of the right channel DC power supply; the positive input terminals of all the optocouplers in the optocoupler group are combined together and connected to the corresponding conductor keys; the positive wire of the right channel DC power supply serves as the control line of the switching circuit and is connected to the wire input terminal on the right channel conductor glove.

3. An electronic keyboard musical instrument, characterized in that: The device comprises a piano key, a carbon film contact under the key, and a sound source chip on a mainboard, wherein the piano key is a conductor key; The carbon film contacts are relatively independent; The left and right hands or each finger of the keyboard player respectively correspond to one or a group of relatively independent sound source chips; A switch circuit is provided between the conductor keys and the relatively independent carbon film contacts below them and the sound source chips corresponding to the left and right hands or each finger respectively; Playing electronic keyboard instruments with conductor keys requires the use of conductor gloves; By pressing any of the conductive keys with the left or right hand or a finger of the person wearing the conductive glove, the corresponding optocoupler group in the related switch circuit can be controlled, and the corresponding pin in the related sound source chip can be further controlled; In a two-channel switch circuit corresponding to the left and right hands playing a keyboard instrument, or in a multi-channel switch circuit corresponding to multiple fingers playing a keyboard instrument, each switch circuit includes a single-chip microcomputer circuit and a photocoupler group that matches the number of keys; Between two or more single-chip microcomputer circuits, the input pin wires at the same position are combined together and connected to the corresponding conductor keys in sequence; In each of the switch circuits, the optocoupler group corresponding to the piano key is arranged between the output terminal corresponding to the single chip microcomputer circuit and the VCC pin or the GND pin; Each of the single chip microcomputer circuits leads out a high and low level control line as a control line of the switch circuit, which is connected to the wire input end on the corresponding conductor glove.

4. The electronic keyboard musical instrument according to claim 3, wherein: In each of the single-chip microcomputer circuits, each of the optocoupler groups is controlled by a driving optocoupler; the positive input terminal of the driving optocoupler is connected to the VCC pin, and the negative input terminal of the driving optocoupler is connected to the output terminal corresponding to the single-chip microcomputer circuit; in each of the optocoupler groups, the positive input terminals of all the optocouplers are combined and connected to the negative output terminal of the driving optocoupler; the positive output terminal of the driving optocoupler is connected to the VCC pin of the single-chip microcomputer circuit; the negative input terminal of each optocoupler in each of the optocoupler groups is connected one-to-one to different partitions of relatively independent non-common carbon film contacts under the corresponding conductor key; the common carbon film contact is connected to the output terminal corresponding to the single-chip microcomputer circuit through a directional diode.

5. The electronic keyboard musical instrument according to claim 3, wherein: In each of the single-chip microcomputer circuits, the positive input terminals of all the optocouplers in the optocoupler group are combined together and connected to the VCC pin of the single-chip microcomputer circuit; the negative input terminals of all the optocouplers in the optocoupler group are combined together and connected to the corresponding output terminals of the single-chip microcomputer circuit.

6. An electronic keyboard musical instrument, characterized by: The device comprises a piano key, a carbon film contact under the key, and a sound source chip on a mainboard, wherein the piano key is a conductor key; The carbon film contacts are relatively independent; The left and right hands playing the keyboard instrument correspond to one or a group of relatively independent sound source chips respectively; A switch circuit is provided between the conductor keys and the relatively independent carbon film contacts below them and the sound source chips corresponding to the left and right hands respectively; Playing electronic keyboard instruments with conductor keys requires the use of conductor gloves; The left or right hand wearing the conductive glove presses any of the conductive keys to control the corresponding optocoupler group in the related switch circuit, and further control the corresponding pin in the related sound source chip; The switching circuit includes a left channel switching circuit and a right channel switching circuit; The left channel switching circuit and the right channel switching circuit include a DC power supply and a number of optocoupler groups that matches the number of piano keys, or include a single-chip microcomputer circuit and a number of optocoupler groups that matches the number of piano keys; Wherein, each of the optocoupler groups in the right channel switch circuit is controlled by a corresponding optocoupler normally closed solid-state relay, and the corresponding optocoupler normally closed solid-state relay is controlled by the left channel switch circuit; When the left hand wearing the conductive glove presses the piano key, the corresponding optocoupler group in the left channel switch circuit will be activated, and at the same time, the corresponding optocoupler normally closed solid-state relay will be used to close the corresponding optocoupler group in the right channel switch circuit under the same key.

7. The electronic keyboard musical instrument according to claim 6, wherein: In the left-channel switching circuit, the positive input terminals of all optocouplers in the optocoupler group are combined and connected to the positive wire of the left-channel DC power supply. The negative input terminal of each optocoupler in the optocoupler group is connected one-to-one to different partitions of relatively independent non-common carbon film contacts under the corresponding conductor key. The common carbon film contacts are connected to the corresponding conductor keys. The negative wire of the left-channel DC power supply serves as the control line of the switching circuit and is connected to the wire input terminal on the left-channel conductor glove. In the right channel switching circuit, the positive input terminals of all the optocouplers in each optocoupler group are combined and connected to the negative output terminal of a corresponding optocoupler normally closed solid-state relay; the positive output terminal of the corresponding optocoupler normally closed solid-state relay is connected to the positive wire of the right channel DC power supply; the negative input terminal of each optocoupler in each optocoupler group is connected one-to-one to different partitions of the relatively independent non-common carbon film contacts under the corresponding conductor key; the common carbon film contact is connected to the negative wire of the right channel DC power supply through a directional diode.

8. The electronic keyboard musical instrument according to claim 6, wherein: In the left channel switching circuit, the positive input terminals of all the optocouplers in each optocoupler group are combined together and connected to the positive wire of the left channel DC power supply; the negative input terminals of all the optocouplers in each optocoupler group are combined together and connected to the corresponding conductor key; the negative wire of the left channel DC power supply serves as the control line of the switching circuit and is connected to the wire input terminal on the left channel conductor glove; In the right channel switching circuit, the positive input terminals of all the optocouplers in each optocoupler group are combined together and connected to the negative output terminal of the corresponding optocoupler normally closed solid-state relay; the positive output terminal of the corresponding optocoupler normally closed solid-state relay is connected to the positive wire of the right channel DC power supply; the negative input terminals of all the optocouplers in each optocoupler group are combined together and connected to the negative wire of the right channel DC power supply through a directional diode.

9. The electronic keyboard musical instrument according to any one of claims 7 and 8, wherein: The positive input terminal of the optocoupler normally closed solid-state relay is connected to the positive wire of the DC power supply in the left channel switch circuit; the negative input terminal of the optocoupler normally closed solid-state relay is connected to the corresponding conductor key.

10. The electronic keyboard musical instrument according to claim 6, wherein: In the left-channel switching circuit, the positive input terminal of each optocoupler in the optocoupler group is connected one-to-one to different partitions of relatively independent non-common carbon film contacts under the corresponding conductor key, and the common carbon film contact is connected to the positive wire of the DC power supply; the negative input terminals of all the optocouplers in the optocoupler group are combined and connected to the corresponding conductor key; the negative wire of the DC power supply serves as the control line of the left-channel switching circuit and is connected to the wire input terminal on the conductor glove; In the right channel switching circuit, the positive input terminal of each optocoupler in the optocoupler group is connected one-to-one to different partitions of the relatively independent non-common carbon film contacts under the corresponding conductor key, and the negative input terminals of all optocouplers in the optocoupler group are combined together and connected to the positive output terminal of a corresponding optocoupler normally closed solid-state relay, and the negative output terminal of the corresponding optocoupler normally closed solid-state relay is connected to the negative wire of the DC power supply.

11. The electronic keyboard musical instrument according to claim 6, wherein: In the left channel switching circuit, the positive input terminals of all the optocouplers in each optocoupler group are combined together and connected to the positive wire of the DC power supply; the negative input terminals of all the optocouplers in each optocoupler group are combined together and connected to the corresponding conductor key; the negative wire of the DC power supply serves as the control line of the left channel switching circuit and is connected to the wire input terminal on the conductor glove; In the right channel switching circuit, the positive input terminals of all the optocouplers in each optocoupler group are combined together and connected to the negative output terminal of the corresponding optocoupler normally closed solid-state relay; the positive output terminal of the corresponding optocoupler normally closed solid-state relay is connected to the positive wire of the DC power supply; the negative input terminals of all the optocouplers in each optocoupler group are combined together and connected to the negative wire of the DC power supply.

12. The electronic keyboard musical instrument according to any one of claims 10 and 11, wherein: The positive input terminal of the optocoupler normally closed solid-state relay is connected to the positive wire of the DC power supply; the negative input terminal of the optocoupler normally closed solid-state relay is connected to the corresponding conductor key.

13. The electronic keyboard musical instrument according to claim 6, wherein: In the left-channel switching circuit, the positive input terminal of each optocoupler in each optocoupler group is connected one-to-one to different partitions of relatively independent non-common carbon film contacts under the corresponding conductor key; the common carbon film contact is connected to the VCC pin of the single-chip microcomputer circuit; the negative input terminals of all optocouplers in each optocoupler group are combined and connected to the corresponding output terminal of the single-chip microcomputer circuit; the high and low level control lines of the single-chip microcomputer circuit serve as control lines of the switching circuit and are connected to the wire input terminal of the left-channel conductor glove; In the right channel switching circuit, the positive input terminal of each optocoupler in each optocoupler group is connected one-to-one to different partitions of relatively independent non-common carbon film contacts under the corresponding conductor key; the common carbon film contact is connected to the VCC pin of the microcontroller circuit; the negative input terminals of all optocouplers in each optocoupler group are combined together and connected to the positive output terminal of the corresponding optocoupler normally closed solid-state relay, and the negative output terminal of the corresponding optocoupler normally closed solid-state relay is connected to the GND pin of the microcontroller circuit.

14. The electronic keyboard musical instrument according to claim 6, wherein: In the left channel switching circuit, the positive input terminals of all optocouplers in each optocoupler group are combined and connected to the VCC pin of the single-chip microcomputer circuit; the negative input terminals of all optocouplers in each optocoupler group are combined and connected to the corresponding output terminals of the single-chip microcomputer circuit; the high and low level control lines of the single-chip microcomputer circuit serve as control lines of the switching circuit and are connected to the wire input terminals on the left channel conductor glove; In the right channel switching circuit, the positive poles of the input ends of all optocouplers in each optocoupler group are combined together and connected to the negative pole of the output end of the corresponding optocoupler normally closed solid-state relay; the positive pole of the output end of the corresponding optocoupler normally closed solid-state relay is connected to the VCC pin of the microcontroller circuit; the negative poles of the input ends of all optocouplers in each optocoupler group are combined together and connected to the GND pin of the microcontroller circuit.

15. The electronic keyboard musical instrument according to any one of claims 13 and 14, wherein: The positive input terminal of the optocoupler normally closed solid-state relay is connected to the VCC pin of the single-chip microcomputer circuit; the negative input terminal of the optocoupler normally closed solid-state relay is connected to the corresponding output terminal of the single-chip microcomputer circuit.

16. The electronic keyboard musical instrument according to any one of claims 1, 4, 7, 10, and 13, wherein: In each switching circuit, the positive and negative output pins of each optocoupler in the optocoupler group are respectively combined with the same output pins of the optocouplers at the same position in other optocoupler groups in the same circuit, using the matrix key rules of traditional electronic keyboard instruments, and then connected to the corresponding pins of the relevant sound source chip.

17. The electronic keyboard musical instrument according to any one of claims 2, 5, 8, 11, and 14, wherein: In each switching circuit, one pin of each optocoupler output end in the optocoupler group is connected to the corresponding carbon film contact end wire; another pin of each optocoupler output end in the optocoupler group is matrix synthesized with the same output end pin of the optocoupler at the same position in other optocoupler groups in the same circuit according to the matrix key rules of traditional electronic keyboard instruments, and then connected to the corresponding pin of the relevant sound source chip.

18. The electronic keyboard musical instrument according to any one of claims 1, 4, 7, 10, and 13, wherein: In a two-channel or multi-channel switching circuit, in each of the optocoupler groups in each of the switching circuits, there are twice or more optocouplers corresponding to the non-common carbon film contacts under the keyboard, which respectively control the corresponding pins in the relevant two or more sound source chips, thereby realizing the timbre superposition stereo of the electronic keyboard instrument.

19. An electronic keyboard musical instrument comprising keys, carbon film contacts underneath the keys, and a sound source chip on a mainboard, characterized by: The left and right hands playing the keyboard instrument correspond to one or a group of relatively independent sound source chips respectively; The keys are divided into a left keyboard area and a right keyboard area; A left channel switching circuit is provided between the carbon film contacts under the keys in the left keyboard area and the sound source chip corresponding to the left hand; A right channel switching circuit is set between the carbon film contacts under the keys in the right keyboard area and the sound source chip corresponding to the right hand; The left channel switching circuit and the right channel switching circuit include a common DC power supply and a photocoupler group having the same number as the corresponding partitioned keys; When you press the keys with your left or right hand, the conductive rubber covers the carbon film contacts, which can control the corresponding optocoupler group in the relevant switch circuit, and further control the corresponding pins in the relevant sound source chip; In the left and right channel switching circuits, the positive input terminals of all the optocouplers in each optocoupler group are combined together and connected to the positive wire of the DC power supply; the negative input terminal of each optocoupler in each optocoupler group is connected one-to-one to different partitions of relatively independent non-common carbon film contacts under the corresponding keys; the common carbon film contacts under the corresponding keys are combined together and connected to the negative wire of the DC power supply.

20. The electronic keyboard musical instrument according to claim 19, wherein: In the left channel switching circuit, the positive input terminals of all the optocouplers in each optocoupler group are combined and connected to the negative output terminals of the corresponding optocoupler normally closed solid-state relays; the positive output terminals of the corresponding optocoupler normally closed solid-state relays are connected to the positive lead of a DC power supply; the negative input terminals of each optocoupler in each optocoupler group are connected one-to-one to different partitions of relatively independent non-common carbon film contacts under the corresponding keys; In the right channel switching circuit, the positive input terminals of all the optocouplers in each optocoupler group are combined and connected to the negative output terminals of the corresponding common optocouplers; the positive output terminals of the corresponding common optocouplers are connected to the positive lead of the DC power supply; the negative input terminals of each optocoupler in each optocoupler group are connected one-to-one to different partitions of relatively independent non-common carbon film contacts under the corresponding keys; The positive input terminals of the optocoupler normally closed solid-state relay in the left channel switch circuit and the ordinary optocoupler in the right channel switch circuit under the same key are combined together and connected to the positive wire of the DC power supply; the negative input terminals are combined together and connected to the negative wire of the DC power supply through a controllable switch; by controlling the two-in-one switches in sequence, the keyboard partition of the left keyboard area or the right keyboard area can be expanded.

21. The electronic keyboard instrument according to any one of claims 19 and 20, wherein: In each switching circuit, the positive and negative output pins of each optocoupler in the optocoupler group are respectively combined with the same output pins of the optocouplers at the same position in other optocoupler groups in the same circuit, using the matrix key rules of traditional electronic keyboard instruments, and then connected to the corresponding pins of the relevant sound source chip.

22. The electronic keyboard musical instrument according to any one of claims 19 and 20, wherein: In the two-channel switching circuit, in each of the optocoupler groups in each of the switching circuits, there are twice or more optocouplers corresponding to the non-common carbon film contacts under the keyboard, which respectively control the corresponding pins in the relevant two or more sound source chips, thereby realizing the timbre superposition stereo of the electronic keyboard instrument.

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