A multi-channel arbitrary switching speaker control system

Abstract

The present invention discloses a multi-channel, arbitrarily switchable speaker control system, comprising one or more output speaker players arranged in different areas, and the following components: one or more microphone / line receiving circuits; a multimedia playback processing circuit capable of receiving USB, SD, Bluetooth, or FM signals; a limiter protection circuit having the same number of output speaker players as the number of output speaker players and capable of being connected to a corresponding output speaker player; a switch selection circuit that selects a designated path for the output connection of each group of microphone / line receiving circuits and multimedia playback processing circuits and, after being turned on, switches the output to the output speaker player corresponding to the designated area; the output of each limiter protection circuit is connected to the corresponding output speaker player via a power amplifier circuit, and each microphone / line receiving circuit is connected to the switch selection circuit via an EQ adjustment circuit. The present invention improves safety and facilitates switching as needed.

Description

Technical Field

[0001] The present invention relates to the technical field of speaker control, in particular to a multi-channel arbitrary switching speaker control system. Background Art

[0002] A speaker is a device that converts audio signals into sound. Generally speaking, it refers to a speaker cabinet or subwoofer housing with a built-in power amplifier that amplifies the audio signal before reproducing it, making the sound louder. The speaker is the terminal of the entire sound system, converting the electrical energy of the audio into sound energy and radiating it into the air. It is an extremely important component of the sound system, responsible for converting electrical signals into sound signals for direct human hearing.

[0003] With the popularity of speakers, they are widely used in many public places. For example, speakers are installed in many places in various public places such as squares, parks, and schools. The content played in the same public place should be consistent, so a control system is set up to control all speaker devices in the entire public place to play or not play synchronously. However, the playback of the entire speaker control system is currently synchronized, which makes the operation relatively inconvenient and unable to switch the playback on and off as needed. In addition, the entire circuit structure of the current playback system is relatively complex and unstable, so it needs to be improved. Summary of the Invention

[0004] The purpose of the present invention is to solve the above-mentioned deficiencies in the prior art and to provide a multi-channel arbitrarily switched speaker control system that can switch lines as needed, has a relatively simple overall circuit structure, and is safer to use.

[0005] To achieve the above objectives, the present invention provides a multi-channel speaker control system with arbitrary switching, including one or more output speaker players arranged in different areas, and the following components:

[0006] One or more microphone / line receiving circuits capable of receiving and processing microphone signals or line signals;

[0007] A multimedia playback processing circuit capable of receiving USB, SD, Bluetooth or FM signals;

[0008] The number of the output speaker players is the same as that of the output speaker players and the limiting protection circuit can be connected to a corresponding output speaker player to control the volume of the speaker and ensure the normal output voltage;

[0009] The output connection of each group of microphone / line receiving circuit and multimedia playback processing circuit has a switch selection circuit that selects a specified path and can switch the output to the output speaker player corresponding to the specified area after being turned on;

[0010] The output of each limit protection circuit is connected to the corresponding output speaker player through a power amplifier circuit, and each microphone / line receiving circuit is connected to the switch selection circuit through an EQ adjustment circuit.

[0011] Furthermore, in order to make the circuit simpler, the structure of each microphone / line receiving circuit is the same, and the specific structure of one group of microphone / line receiving circuits is as follows: it includes a microphone jack MIC1, a first transport amplifier U1A and a line terminal Line1, a first inductor L1, a first resistor R1, and a third resistor R3 are connected in series between pin 3 of the microphone jack MIC1 and the non-inverting terminal of the first transport amplifier U1A, and a second inductor L2, a second resistor R2, and a third resistor R3 are connected in series between pin 3 of the microphone jack MIC1 and the inverting terminal of the first transport amplifier U1A. A first switching switch K1B for switching the microphone input is connected between the common end connected to the four resistors R4, the first resistor R1, and the third resistor R3, and the non-inverting end of the first transport amplifier U1A. A second switching switch K1A for switching the line input is connected between the common end connected to the second resistor R2 and the fourth resistor R4, and the inverting end of the first transport amplifier U1A. A sixth resistor R6 and a fourth capacitor C4 are connected in parallel between the inverting end and the ground end of the first transport amplifier U1A. A diode D is connected between the non-inverting end and the inverting end of the first transport amplifier U1A and the positive 15V and negative 15V power supply voltages.

[0012] Furthermore, to simplify the circuit, the multimedia playback processing circuit includes a USB port USB IN and a third transport amplifier U3A. A thirty-third resistor R33 is connected between pin 3 of the USB port USB IN and the inverting terminal of the third transport amplifier U3A. A thirty-fifth resistor R35 and a nineteenth capacitor C19 are connected in parallel between the inverting terminal of the third transport amplifier U3A and the output terminal of the third transport amplifier U3A. A twentieth capacitor C20 is connected to the output terminal of the third transport amplifier U3A.

[0013] Furthermore, to simplify the circuit, the structure of each switch selection circuit is identical, and the specific structure of one group of switch selection circuits is as follows: it includes switching units arranged in parallel and having the same number as the output speaker players, and each group of switching units has the same structure. One group of switching units includes a double-pole double-throw switch SW9A, a first light-emitting diode G, and a sixth transport amplifier U6A. Pin 3 of the double-pole double-throw switch SW9A is connected to the output end of the EQ adjustment circuit, pin 2 of the double-pole double-throw switch SW9A is connected to the inverting input end of the sixth transport amplifier U6A via a seventy-eighth resistor R78, the output end of the sixth transport amplifier U6A is connected to a fortieth capacitor C40, a one-hundredth resistor R100 and a thirty-ninth capacitor C39 are arranged in parallel between the inverting end of the sixth transport amplifier U6A and the output end of the sixth transport amplifier U6A, pin 5 of the double-pole double-throw switch SW9A is connected to the ground end via the first light-emitting diode G, and pin 6 of the double-pole double-throw switch SW9A is connected to a +12V voltage via a seventy-ninth resistor R79.

[0014] Furthermore, in order to make the circuit simpler, the structure of each EQ adjustment circuit is the same, and the specific structure of one group of EQ adjustment circuits is as follows: it includes a second transport amplifier U2A, and a fifth capacitor C5, a first sliding resistor RP1A, a thirty-eighth resistor R38, a sixth sliding resistor RP6A and a fortieth resistor R40 are connected in series between the inverting input terminal of the second transport amplifier U2A and the output terminal of the first transport amplifier U1A, one end of the first sliding resistor RP1A is connected to the fifth capacitor C5, and the other end is grounded, the sliding end of the first sliding resistor RP1A is connected to one end of the thirty-eighth resistor R38, one end of the sixth sliding resistor RP6A is connected to the other end of the thirty-eighth resistor R38, the other end of the sixth sliding resistor RP6A is connected to the output terminal of the second transport amplifier U2A through the thirty-ninth resistor R39, the sliding end of the sixth sliding resistor RP6A is connected to one end of the fortieth resistor R40, and the thirty-ninth resistor An eighth capacitor C8 is connected in parallel to R39, and a thirty-sixth resistor R36, a fifth sliding resistor RP6A and a sixth capacitor C6 are connected in series between the common end of the thirty-eighth resistor R38 and the sliding end of the first sliding resistor RP1A and the inverting input end of the second transport amplifier U2A. One end of the fifth sliding resistor RP6A is connected to the thirty-sixth resistor R36, and the other end is connected to the output end of the second transport amplifier U2A through the thirty-seventh resistor R37. The sliding end of the first sliding resistor RP1A is connected to one end of the sixth capacitor C6. The eighth capacitor C8 is connected between the output end of the second transport amplifier U2A and the inverting input end of the second transport amplifier U2A. The output end of the second transport amplifier U2A is connected to pin 3 of the double-pole double-throw switch in all switching units 6 in the corresponding switch selection circuit 4 through the ninth capacitor C9. The inverting input end of the second transport amplifier U2A and the output end of the first transport amplifier U1A are connected together and connected by a wiring.

[0015] Furthermore, in order to make the circuit simpler, the amplitude limiting protection circuit 3 includes an eighth transport amplifier U8A, an eighth transport amplifier U8B and a twelfth transport amplifier U12A. The inverting input terminal of the eighth transport amplifier U8A is connected in series with a thirteenth sliding resistor RP13A, a one-hundred-eighth resistor R108 and a one-hundred-ninth resistor R109. One end of the thirteenth sliding resistor RP13A is connected to the other end of the fortieth capacitor C40, and the other end is grounded. The sliding end of the first sliding resistor RP1A is connected to one end of the one-hundred-eighth resistor R108, and the sliding end of the first sliding resistor RP1A is connected to the one-hundred-eighth resistor R108. The power supply end is connected to the inverting input end of the twelfth transport amplifier U12A through the 117th resistor R117. A 49th capacitor C49 and an 11th diode R112 are connected in parallel between the inverting input end of the twelfth transport amplifier U12A and the output end of the twelfth transport amplifier U12A. The output end of the twelfth transport amplifier U12A is connected to the anode of the 111th diode D111. A first PNP transistor Q1 is connected to the common end of the 108th resistor R108 and the 109th resistor R109. The collector of the first PNP transistor Q1 is connected to the 108th resistor R108. The base of the first PNP transistor Q1 is connected to the 82nd transport amplifier U12A. The output terminal of the amplifier U8B is connected in series with a 116th resistor R116, a 10th diode D10, and a 114th resistor R114. A 48th capacitor C48 and a 115th resistor R115 are connected in parallel between the common terminal of the 116th resistor R116 and the 10th diode D10 and the ground terminal. The non-inverting input terminal of the 82nd transport amplifier U8B and the output terminal of the 81st transport amplifier U8A are connected via a 9th diode D9. The output terminal of the 81st transport amplifier U8A and the inverting input terminal of the 82nd transport amplifier U8B are connected via a 111th resistor R111. The output of the 81st transport amplifier U8A is connected in series with an 85th capacitor C85, The eighty-sixth capacitor C86 is connected to the non-inverting input terminal of the sixteenth transport amplifier U16A, the common terminal of the eighty-fifth capacitor C85 and the eighty-sixth capacitor C86 is connected to the inverting input terminal of the sixteenth transport amplifier U16A, the output terminal of the sixteenth transport amplifier U16A is connected to the fifth switching switch K5A through the eighty-sixth resistor R210, the normally closed contact of the fifth switching switch K5A is connected to the output terminal of the eighty-first transport amplifier U8A through the eighty-sixth resistor group R186, the common terminal of the fifth switching switch K5A is directly connected to the inverting input terminal of a corresponding power amplifier, that is, the IN1 terminal, for power amplification, and the amplified signal is directly sent to the speaker for playback.

[0016] The technical effect of the multi-channel arbitrarily switched speaker control system obtained by the present invention is: through the above-mentioned circuit structure design, it is possible to select the power amplifier output status to be switched according to needs, and finally switch the playback to the required area. Moreover, the entire circuit structure is relatively simple, and the limiting protection circuit designed in the entire circuit makes the circuit safer and more stable. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a principle block diagram of a multi-channel arbitrary switching speaker control system in Example 1;

[0018] Figure 2 is a schematic diagram of the microphone / line receiving circuit of channel 1 in Example 1;

[0019] Figure 3 is a schematic diagram of the switch selection circuit and EQ adjustment circuit of channel 1 in Example 1;

[0020] Figure 4 is a schematic diagram of the multimedia playback processing circuit and switch selection circuit of channel 5 in Example 1;

[0021] Figure 5 is a schematic diagram of the microphone / line receiving circuit, switch selection circuit, and EQ adjustment circuit of channel 2 in Example 1;

[0022] Figure 6 is a schematic diagram of the microphone / line receiving circuit, switch selection circuit, and EQ adjustment circuit of channel 3 in Example 1;

[0023] Figure 7 is a schematic diagram of the microphone / line receiving circuit, switch selection circuit, and EQ adjustment circuit of channel 4 in Example 1;

[0024] Figure 8 This is a circuit schematic diagram of the power supply module that supplies power to various devices in Example 1;

[0025] Figure 9 is a circuit schematic diagram of the amplitude limiting protection circuit of channel 1 in Example 1;

[0026] Figure 10 is a circuit schematic diagram of the amplitude limiting protection circuit of channel 2 in Example 1;

[0027] Figure 11 is a circuit schematic diagram of the amplitude limiting protection circuit of channel 3 in Example 1;

[0028] Figure 12 is a circuit schematic diagram of the amplitude limiting protection circuit of channel 4 in Example 1;

[0029] Figure 13is a circuit schematic diagram of the signal level monitoring circuit of channel 1 in Example 1;

[0030] Figure 14 is a circuit schematic diagram of the signal level monitoring circuit of channel 4 in Example 1;

[0031] Figure 15 is a circuit schematic diagram of the power amplifier circuit of channel 1 in Example 1;

[0032] Figure 16 is a circuit schematic diagram of the power amplifier circuit of channel 2 in Example 1;

[0033] Figure 17 is a circuit schematic diagram of the power amplifier circuit of channel 3 in Example 1;

[0034] Figure 18 is a circuit schematic diagram of the power amplifier circuit of channel 4 in Example 1;

[0035] Figure 19 This is a schematic diagram of a circuit for driving the power amplifier to turn on or off in Example 1.

[0036] In the figure: microphone / line receiving circuit 1, multimedia playback processing circuit 2, limit protection circuit 3, switch selection circuit 4, power amplifier circuit 5, switching unit 6, EQ adjustment circuit 7, power supply module 8. DETAILED DESCRIPTION

[0037] The present invention will be further described below with reference to the accompanying drawings and examples.

[0038] Example 1:

[0039] like Figures 1-19 As shown, this embodiment provides a multi-channel arbitrarily switchable speaker control system, including one or more output speaker players arranged in different areas, and also includes the following components:

[0040] One or more microphone / line receiving circuits 1 capable of receiving and processing microphone signals or line signals;

[0041] A multimedia playback processing circuit 2 capable of receiving USB, SD, Bluetooth or FM signals;

[0042] The number of the output speaker players is the same as that of the output speaker players and the limiting protection circuit 3 can be connected to a corresponding output speaker player to control the volume of the speaker and ensure the normal output voltage;

[0043] The output connection of each group of microphone / line receiving circuit 1 and multimedia playback processing circuit 2 is provided with a switch selection circuit 4 which selects a designated path and switches the output to the output speaker player corresponding to the designated area after being turned on;

[0044] The output of each amplitude limiting protection circuit 3 is connected to the corresponding output speaker player through a power amplifier circuit 5, and each microphone / line receiving circuit 1 is connected to the switch selection circuit 4 through an EQ adjustment circuit 7.

[0045] Furthermore, in order to make the circuit simpler, the structure of each microphone / line receiving circuit 1 is the same, and the specific structure of one group of microphone / line receiving circuits 1 is as follows: it includes a microphone jack MIC1, a first transport amplifier U1A and a line terminal Line1, a first inductor L1, a first resistor R1, and a third resistor R3 are connected in series between pin 3 of the microphone jack MIC1 and the non-inverting terminal of the first transport amplifier U1A, and a second inductor L2, a second resistor R2, and a third resistor R3 are connected in series between pin 3 of the microphone jack MIC1 and the inverting terminal of the first transport amplifier U1A. The fourth resistor R4, the common terminal connecting the first and third resistors R1 and R3, and the non-inverting terminal of the first transport amplifier U1A are connected to a first switch K1B for switching the microphone input. The common terminal connecting the second and fourth resistors R2 and R4, and the inverting terminal of the first transport amplifier U1A, are connected to a second switch K1A for switching the line input. A sixth resistor R6 and a fourth capacitor C4 are connected in parallel between the inverting terminal of the first transport amplifier U1A and ground. A diode D is connected between the non-inverting and inverting terminals of the first transport amplifier U1A and the positive and negative 15V power supply voltages. This is the first signal input. The signal passes through two ferrite beads L5 / L6 to remove ultra-high frequency signals, then passes through R9 / R10 / R11 / R12 to the op amp for amplification. These four resistors, in conjunction with switch K2, enable gain selection to accommodate the varying sensitivity requirements of the microphone and line. Diodes D1 / D2 primarily protect the left and right sides of the operational amplifier, clamping the input signal to a maximum value not exceeding the power supply voltage and preventing static electricity from damaging the IC.

[0046] like Figure 8 As shown, in order to increase the stable working voltage of each circuit, a power supply circuit 8 must be provided, so the Figure 8 This improves the stability of the working power supply.

[0047] To further simplify the circuit, the multimedia playback processing circuit 2 includes a USB port (USB IN) and a third transport amplifier (U3A). A thirty-third resistor (R33) is connected between pin 3 of the USB port (USB IN) and the inverting terminal of the third transport amplifier (U3A). A thirty-fifth resistor (R35) and a nineteenth capacitor (C19) are connected in parallel between the inverting terminal of the third transport amplifier (U3A) and the output terminal of the third transport amplifier (U3A). The output terminal of the third transport amplifier (U3A) is connected to a twentieth capacitor (C20). This section primarily amplifies the signal from the multimedia player to ensure stable output. The inverting input terminal of the second transport amplifier (U2A) is connected to the output terminal of the first transport amplifier (U1A) via a flat cable.

[0048] Furthermore, in order to make the circuit simpler, the structure of each switch selection circuit 4 is the same, and the specific structure of one group of switch selection circuits 4 is as follows: it includes switching units 6 arranged in parallel and having the same number of output speaker players, and the structure of each group of switching units 6 is the same, wherein one group of switching units 6 includes a double-pole double-throw switch SW9A, a first light-emitting diode G and a sixth transport amplifier U6A, and the 3rd pin of the double-pole double-throw switch SW9A is connected to the output end of the EQ adjustment circuit 7, and the 2nd pin of the double-pole double-throw switch SW9A is connected to the output end of the sixth transport amplifier U6A through the seventy-eighth resistor R78. The inverting input terminal and the output terminal of the sixth transport amplifier U6A are connected to a 40th capacitor C40. A 100th resistor R100 and a 39th capacitor C39 are connected in parallel between the inverting terminal of the sixth transport amplifier U6A and the output terminal of the sixth transport amplifier U6A. Pin 5 of the double-pole double-throw switch SW9A is connected to ground via a first light-emitting diode G, and pin 6 of the double-pole double-throw switch SW9A is connected to a +12V voltage via a 79th resistor R79. In this structure, each input signal undergoes volume adjustment and EQ tuning, then passes through four selector switches to transmit the signal to four different outputs, achieving zone control. That is, the signal can be selectively transmitted to the location where it is needed, while no sound is heard in locations where it is not needed.

[0049] Furthermore, in order to make the circuit simpler, the structure of each EQ adjustment circuit 7 is the same, and the specific structure of one group of EQ adjustment circuits 7 is as follows: it includes a second transport amplifier U2A, and a fifth capacitor C5, a first sliding resistor RP1A, a thirty-eighth resistor R38, a sixth sliding resistor RP6A and a fortieth resistor R40 are connected in series between the inverting input terminal of the second transport amplifier U2A and the output terminal of the first transport amplifier U1A. One end of the first sliding resistor RP1A is connected to the fifth capacitor C5, and the other end is grounded. The sliding end of the first sliding resistor RP1A is connected to one end of the thirty-eighth resistor R38, one end of the sixth sliding resistor RP6A is connected to the other end of the thirty-eighth resistor R38, and the other end of the sixth sliding resistor RP6A is connected to the output terminal of the second transport amplifier U2A through the thirty-ninth resistor R39. The moving end is connected to one end of the 40th resistor R40, and the eighth capacitor C8 is connected in parallel to the 39th resistor R39. The 36th resistor R36, the fifth sliding resistor RP6A and the sixth capacitor C6 are connected in series between the common end connected to the sliding end of the 38th resistor R38 and the first sliding resistor RP1A and the inverting input end of the second transport amplifier U2A. One end of the fifth sliding resistor RP6A is connected to the 36th resistor R36, and the other end is connected to the output end of the second transport amplifier U2A through the 37th resistor R37. The sliding end of the first sliding resistor RP1A is connected to one end of the sixth capacitor C6. The eighth capacitor C8 is connected between the output end of the second transport amplifier U2A and the inverting input end of the second transport amplifier U2A. The output end of the second transport amplifier U2A is connected to pin 3 of the double-pole double-throw switch in all switching units 6 in the corresponding switch selection circuit 4 through the ninth capacitor C9. In this structure, the first signal is amplified and then blocked by the C5 capacitor to block the DC. The volume is adjusted by the potentiometer RP1, the resistors R38 / R39 / C7 are used for bass selection, and the potentiometer RP6 can adjust the bass intensity. The resistors R36 / R37 / C6 are used for high-frequency selection, and the potentiometer RP5 is used to adjust the treble content. After the current of the operational amplifier U2A is amplified, it is filtered by C9 to remove the DC bias of the operational amplifier. The signal is sent to the 4-way switch for signal selection and output, and the other channels are also implemented using the same control method.

[0050] Furthermore, in order to make the circuit simpler, the amplitude limiting protection circuit 3 includes an eighty-first transport amplifier U8A, an eighty-second transport amplifier U8B and a twelfth transport amplifier U12A. The inverting input terminal of the eighty-first transport amplifier U8A is connected in series with a thirteenth sliding resistor RP13A, a one-hundred-and-eighth resistor R108 and a one-hundred-and-ninth resistor R109. One end of the thirteenth sliding resistor RP13A is connected to the other end of the fortieth capacitor C40, and the other end is grounded. The sliding end of the first sliding resistor RP1A is connected to one end of the one-hundred-and-eighth resistor R108. The power supply end connected to the sliding end of the first sliding resistor RP1A and the one-hundred-and-eighth resistor R108 is connected to the twelfth transport amplifier through the one-hundred-seventeenth resistor R117. The inverting input terminal of the twelfth transport amplifier U12A is connected to the inverting input terminal of the twelfth transport amplifier U12A, a forty-ninth capacitor C49 and an eleventh diode R112 are connected in parallel between the inverting input terminal of the twelfth transport amplifier U12A and the output terminal of the twelfth transport amplifier U12A, the output terminal of the twelfth transport amplifier U12A is connected to the anode of the one hundred eleventh diode D111, a first PNP transistor Q1 is connected to the common terminal of the one hundred and eighth resistor R108 and the one hundred and ninth resistor R109, the collector of the first PNP transistor Q1 is connected to the one hundred and eighth resistor R108, a one hundred and sixteenth resistor R116, a tenth diode D10 and a one hundred and fourteenth resistor R114 are connected in series between the base of the first PNP transistor Q1 and the output terminal of the eighty-second transport amplifier U8B, A forty-eighth capacitor C48 and a one-hundred-fifth resistor R115 are connected in parallel between the common terminal of the sixteenth resistor R116 and the tenth diode D10 and the ground terminal. A ninth diode D9 is connected to the non-inverting input terminal of the eighty-second transport amplifier U8B and the output terminal of the eighty-first transport amplifier U8A. A one-hundred-eleventh resistor R111 is connected to the output terminal of the eighty-first transport amplifier U8A and the inverting input terminal of the eighty-second transport amplifier U8B. The output of the eighty-first transport amplifier U8A is connected to the non-inverting input terminal of the sixteenth transport amplifier U16A via an eighty-fifth capacitor C85 and an eighty-sixth capacitor C86 connected in series. The common terminal of the eighty-fifth capacitor C85 and the eighty-sixth capacitor C86 is connected to the inverting input terminal of the sixteenth transport amplifier U16A. The output end of the sixteenth transport amplifier U16A is connected to the fifth switch K5A through the second resistor R210. The normally closed contact of the fifth switch K5A is connected to the output end of the eighty-first transport amplifier U8A through the first resistor R186. The fifth switch K5A is directly connected to the inverting input end of the corresponding power amplifier, that is, the IN1 end, for power amplification. The amplified signal is directly sent to the speaker for playback. After the signal is selected by the switch and then adjusted by the RP13 volume, it enters U8A for signal amplification. U8B is used as a comparator. When the signal is greater than a certain value, it outputs a high level and controls the junction field effect transistor Q1 to limit the signal to prevent the power amplifier from overloading due to excessive signal, thereby protecting the power amplifier and the speaker.The C48 capacitor delays the limiting signal, thus ultimately playing the role of a limiting protection circuit, and the ON of the op amp is connected to the corresponding output speaker player, realizing the working state of the subsequent output speaker player.

[0051] Figure 13 、 Figure 14 The function is to monitor the signal level. 5 LED lights are controlled by 5 comparators. The resistors R125 / 126 / 127 / 128 / 129 / 130 set the flip threshold of each comparator. When the signal changes from small to large, the corresponding comparators are turned on one by one, and the LEDs light up one by one. When the last LED lights up, it means that the signal has reached the maximum. At this time, it is necessary to reduce the volume appropriately to avoid signal overload. Therefore, by setting Figure 13 、 Figure 14 The circuit structure can further control the volume of the entire amplifier.

[0052] Figure 19 The circuit principle for driving the on / off state is as follows: CN1 is the power from the transformer. The main power is rectified by D1 and filtered by C1-C4 before being supplied to the amplifier. Q1 / Q2 are voltage regulators, stepping down and stabilizing the main power before supplying power to the pre-amplifier. The auxiliary power, which powers the multimedia player, is rectified by D2-D5 and filtered by C11 before being supplied to the player. After rectification by D6 / D7, the power passes through transistors Q3 / Q4 to set the amplifier's shutdown mute circuit. When the power switch is turned off, this circuit quickly shuts down the amplifier, preventing surge noise caused by voltage imbalance in the op-amp during the voltage drop.

[0053] Therefore, through the circuit structure design created by the present invention, it is possible to select and switch the power amplifier output according to needs, and finally switch the playback to the required area. Moreover, the entire circuit structure is relatively simple, and the design of the limiting protection circuit 3 in the entire circuit makes the circuit safer and more stable.

Claims

1. A multi-channel arbitrarily switched speaker control system, comprising more than one output speaker player arranged in different areas, characterized in that: Also includes the following components: One or more microphone / line receiving circuits capable of receiving and processing microphone signals or line signals (1); A multimedia playback processing circuit (2) capable of receiving USB, SD, Bluetooth or FM signals; The number of the output speaker players is the same as that of the output speaker players and the circuit can be connected to a corresponding output speaker player to control the volume of the output speaker player and ensure that the output voltage is normal; The output connection of each group of microphone / line receiving circuit (1) and multimedia playback processing circuit (2) is provided with a switch selection circuit (4) which selects a designated path and switches the output to the output speaker player corresponding to the designated area after being turned on; The output of each amplitude limiting protection circuit (3) is connected to the corresponding output speaker player through a power amplifier circuit (5), and each microphone / line receiving circuit (1) is connected to the switch selection circuit (4) through an EQ adjustment circuit (7).

2. A multi-channel arbitrarily switched speaker control system according to claim 1, characterized in that: The structure of each microphone / line receiving circuit (1) is the same, and the specific structure of one group of microphone / line receiving circuits (1) is as follows: it includes a microphone jack MIC1, a first transport amplifier U1A and a line terminal Line1, a first inductor L1, a first resistor R1 and a third resistor R3 are connected in series between the 3rd pin of the microphone jack MIC1 and the in-phase terminal of the first transport amplifier U1A, a second inductor L2, a second resistor R2 and a fourth resistor R4 are connected in series between the 3rd pin of the microphone jack MIC1 and the inverting terminal of the first transport amplifier U1A, A first switching switch K1B for switching the microphone input is connected between the common end connected by the first resistor R1 and the third resistor R3 and the non-inverting end of the first transport amplifier U1A. A second switching switch K1A for switching the line input is connected between the common end connected by the second resistor R2 and the fourth resistor R4 and the inverting end of the first transport amplifier U1A. A sixth resistor R6 and a fourth capacitor C4 are connected in parallel between the inverting end and the ground end of the first transport amplifier U1A. A diode D1 / D2 is connected between the non-inverting end and the inverting end of the first transport amplifier U1A and the positive 15V and negative 15V power supply voltages.

3. A multi-channel arbitrarily switched speaker control system according to claim 2, characterized in that: The multimedia playback processing circuit (2) includes a USB plug interface USB IN and a third transport amplifier U3A, a thirty-third resistor R33 is connected between pin 3 of the USB plug interface USB IN and the inverting end of the third transport amplifier U3A, a thirty-fifth resistor R35 and a nineteenth capacitor C19 are connected in parallel between the inverting end of the third transport amplifier U3A and the output end of the third transport amplifier U3A, and a twentieth capacitor C20 is connected to the output end of the third transport amplifier U3A.

4. A multi-channel arbitrarily switched speaker control system according to claim 3, characterized in that: The structure of each switch selection circuit (4) is the same, and the specific structure of one group of switch selection circuits (4) is as follows: it includes switching units (6) arranged in parallel and having the same number as the output speaker players, and the structure of each group of switching units (6) is the same, wherein one group of switching units (6) includes a double-pole double-throw switch SW9A, a first light-emitting diode G and a sixth transport amplifier U6A, wherein the 3rd pin of the double-pole double-throw switch SW9A is connected to the output end of the EQ adjustment circuit (7), the 2nd pin of the double-pole double-throw switch SW9A is connected to the inverting input end of the sixth transport amplifier U6A through the seventy-eighth resistor R78, the output end of the sixth transport amplifier U6A is connected to the fortieth capacitor C40, the one-hundredth resistor R100 and the thirty-ninth capacitor C39 are arranged in parallel between the inverting end of the sixth transport amplifier U6A and the output end of the sixth transport amplifier U6A, the 5th pin of the double-pole double-throw switch SW9A is connected to the ground end through the first light-emitting diode G, and the 6th pin of the double-pole double-throw switch SW9A is connected to the +12V voltage through the seventy-ninth resistor R79.

5. A multi-channel arbitrary switching speaker control system according to claim 4, characterized in that: The structure of each EQ adjustment circuit (7) is the same, and the specific structure of one group of EQ adjustment circuits (7) is as follows: it includes a second transport amplifier U2A, a fifth capacitor C5, a first sliding resistor RP1A, a thirty-eighth resistor R38, a sixth sliding resistor RP6A and a fortieth resistor R40 are connected in series between the inverting input terminal of the second transport amplifier U2A and the output terminal of the first transport amplifier U1A, one end of the first sliding resistor RP1A is connected to the fifth capacitor C5, and the other end is grounded, the sliding end of the first sliding resistor RP1A is connected to one end of the thirty-eighth resistor R38, one end of the sixth sliding resistor RP6A is connected to the other end of the thirty-eighth resistor R38, the other end of the sixth sliding resistor RP6A is connected to the output terminal of the second transport amplifier U2A through the thirty-ninth resistor R39, and the sliding end of the sixth sliding resistor RP6A is connected to the fortieth resistor R40. One end of the resistor R40 is connected, and an eighth capacitor C8 is connected in parallel to the thirty-ninth resistor R39. A thirty-sixth resistor R36, a fifth sliding resistor RP6A and a sixth capacitor C6 are connected in series between the common end of the thirty-eighth resistor R38 and the sliding end of the first sliding resistor RP1A and the inverting input end of the second transport amplifier U2A. One end of the fifth sliding resistor RP6A is connected to the thirty-sixth resistor R36, and the other end is connected to the output end of the second transport amplifier U2A through the thirty-seventh resistor R37. The sliding end of the first sliding resistor RP1A is connected to one end of the sixth capacitor C6. An eighth capacitor C8 is connected between the output end of the second transport amplifier U2A and the inverting input end of the second transport amplifier U2A. The output end of the second transport amplifier U2A is connected to pin 3 of the double-pole double-throw switch in all switching units (6) in the corresponding switch selection circuit (4) through the ninth capacitor C9.

6. The multi-channel arbitrary switching speaker control system according to claim 5, characterized in that: The amplitude limiting protection circuit (3) includes an eighty-first transport amplifier U8A, an eighty-second transport amplifier U8B and a twelfth transport amplifier U12A, the inverting input terminal of the eighty-first transport amplifier U8A is connected in series with a thirteenth sliding resistor RP13A, a one-hundred-eighth resistor R108 and a one-hundred-ninth resistor R109, one end of the thirteenth sliding resistor RP13A is connected to the other end of the fortieth capacitor C40, and the other end is grounded, the sliding end of the first sliding resistor RP1A is connected to one end of the one-hundred-eighth resistor R108, and the power supply end connected to the sliding end of the first sliding resistor RP1A and the one-hundred-eighth resistor R108 is connected via a first The one hundred and seventeenth resistor R117 is connected to the inverting input terminal of the twelfth transport amplifier U12A. The forty-ninth capacitor C49 and the eleventh diode R112 are connected in parallel between the inverting input terminal of the twelfth transport amplifier U12A and the output terminal of the twelfth transport amplifier U12A. The output terminal of the twelfth transport amplifier U12A is connected to the anode of the one hundred and eleventh diode D111. The first PNP transistor Q1 is connected to the common terminal of the one hundred and eighth resistor R108 and the one hundred and ninth resistor R109. The collector of the first PNP transistor Q1 is connected to the one hundred and eighth resistor R108. The base of the first PNP transistor Q1 is connected to the eighty-second transport amplifier U8. The output terminal of the eighty-second transport amplifier U8B is connected to the output terminal of the eighty-first transport amplifier U8A via a ninth diode D9, the output terminal of the eighty-first transport amplifier U8A is connected to the inverting input terminal of the eighty-second transport amplifier U8B via a one-hundred-eleventh resistor R111, the output terminal of the eighty-first transport amplifier U8A is connected to the inverting input terminal of the eighty-second transport amplifier U8B via a eighty-fifth capacitor C85, a tenth diode D10 and a one-hundred-fourteenth resistor R114 in series, the common terminal of the one-hundred-sixteenth resistor R116 and the tenth diode D10 are connected to the ground terminal via a forty-eighth capacitor C48 and a one-hundred-fifteenth resistor R115 in parallel, the non-inverting input terminal of the eighty-second transport amplifier U8B is connected to the output terminal of the eighty-first transport amplifier U8A via a ninth diode D9, the output terminal of the eighty-first transport amplifier U8A is connected to the inverting input terminal of the eighty-second transport amplifier U8B via a one-hundred-eleventh resistor R111, the output terminal of the eighty-first transport amplifier U8A is connected to the inverting input terminal of the eighty-second transport amplifier U8B via a one-hundred-eleventh capacitor C85, a tenth diode D10 and a one-hundred-fourth resistor R114 in series, The eighty-sixth capacitor C86 is connected to the non-inverting input terminal of the sixteenth transport amplifier U16A, the common terminal of the eighty-fifth capacitor C85 and the eighty-sixth capacitor C86 is connected to the inverting input terminal of the sixteenth transport amplifier U16A, the output terminal of the sixteenth transport amplifier U16A is connected to the fifth switch K5A via the second resistor R210, the normally closed contact of the fifth switch K5A is connected to the output terminal of the eighty-first transport amplifier U8A via the first resistor R186, the common terminal of the fifth switch K5A is directly connected to the inverting input terminal of a corresponding power amplifier, i.e., the IN1 terminal, for power amplification, and the amplified signal is directly sent to the speaker for playback.

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