Electric contact pressure gauge signal amplification circuit and device

Abstract

The utility model provides an electric contact pressure gauge signal amplification circuit and device, and the circuit comprises a DC power supply module, an electric contact pressure gauge transformation trigger module, a deflection pointer common end which is used for deflecting when the electric contact pressure is expressed to an upper limit and a lower limit, and the deflection pointer common end is coupled to the negative electrode of the DC power supply module; the signal output module is coupled to the positive electrode of the direct-current power supply module, is provided with a semiconductor resistive conduction end and is used for outputting different conduction signals; the signal conversion module is used for receiving the conduction signal and outputting a state switching signal; and the upper and lower limit circuit control module is coupled with the signal processing module and is used for receiving the state switching signal and controlling the connection or disconnection of the upper limit working circuit or the lower limit working circuit according to the state switching signal. The DC 24V power supply is used for supplying power, and the resistive load is used for receiving switching value electric signals of the pointer meter, so that current impact is reduced, and mechanical contacts are protected.

Description

Technical Field

[0001] The utility model relates to the field of switch quantity signal control, in particular to an electric contact pressure gauge signal amplification circuit and a device. Background Art

[0002] Pointer type electric contact pressure gauge is an industrial measuring instrument, which is widely used in various occasions where pressure needs to be monitored and controlled. The core function of this instrument is to display the process pressure through its pointer position, and to connect or disconnect the circuit through the built-in switch contact (alarm contact), so as to monitor and control the pressure.

[0003] The three pointers of the electric contact pressure gauge represent different measurement parameters or control logics. When the actual pressure is lower than the lower limit, the common end deflects and connects to the lower limit; when the actual pressure is between the upper and lower limits, the common end is disconnected from both the upper and lower limits; when the actual pressure is higher than the upper limit, the common end is connected to the upper limit. The electric contact pressure gauge is widely used in various press machine tools for converting pressure values ​​to switch signals and outputting them because of its easy production and manufacturing, low price, simple operation and setting, and convenient circuit wiring.

[0004] The above-mentioned electric contact pressure gauge of the prior art usually causes the electromagnetic induction effect of the relay coil, resulting in a large current being received by the mechanical contacts when the power is just cut off, causing arcing, sintering and melting, making the mechanical contacts easy to be damaged and having a short service life, and also easily causing unreliable on-off of the output signal. Utility Model Content

[0005] The present application provides a signal amplifying circuit for an electric contact pressure gauge, which makes the mechanical contacts less susceptible to damage.

[0006] In a first aspect of the present application, an electric contact pressure gauge signal amplification circuit is provided.

[0007] An electric contact pressure gauge signal amplification circuit, comprising:

[0008] A DC power supply module, used for supplying DC power;

[0009] The electric contact pressure gauge modification trigger module has a deflection pointer common end for deflecting when the electric contact pressure gauge reaches the upper and lower limits, and the deflection pointer common end is coupled to the negative pole of the DC power supply module;

[0010] A signal output module, coupled to the positive electrode of the DC power supply module, having two semiconductor resistive conduction terminals for contacting and electrically connecting with the deflection contact terminal, and used for outputting different conduction signals according to the semiconductor resistive conduction terminals contacted by the deflection contact terminal;

[0011] A signal conversion module, used for receiving a conduction signal and outputting a state switching signal;

[0012] The upper and lower limit circuit control module is coupled to the signal conversion module, and is used to receive the state switching signal and control the upper limit working circuit or the lower limit working circuit to be turned on or off according to the state switching signal.

[0013] Through the above arrangement, the common end of the deflection pointer is electrically contacted with the resistive conduction end of the semiconductor, so that the signal output module is turned on and sends a conduction signal. The conduction signal is received by the signal conversion module and the output state switching signal is sent to the upper and lower limit circuit control module. The upper and lower limit circuit control module indirectly controls the upper limit working circuit or the lower limit working circuit to be turned on and off, so that the common end of the deflection pointer does not need to bear the large current generated when the relay coil is powered off, so that the mechanical contacts on the common end of the deflection pointer are not easily damaged, so that the service life of the signal amplification circuit of the electric contact pressure gauge is extended.

[0014] Preferably, it also includes:

[0015] The light indication module is coupled to the upper and lower limit circuit control module and is used to indicate the conduction state of the upper limit working circuit and the lower limit working circuit by emitting light.

[0016] Preferably, the upper and lower limit circuit control module includes:

[0017] A microprocessing unit, coupled to the signal conversion module, configured to receive a state switching signal and output a driving level;

[0018] The transistor driving unit is coupled to the microprocessing unit and is used to control the on / off of the contact switch of the relay J2 of the upper limit working circuit and the contact switch of the relay J1 of the lower limit working circuit according to the driving level.

[0019] Preferably, it also includes:

[0020] The upper and lower limit circuit control mode switching module is coupled to the microprocessing unit and is used to switch the control program of the microprocessing unit to the upper limit working circuit or the lower limit working circuit.

[0021] Preferably, the microprocessing unit adopts a single chip microcomputer, the microprocessing unit is coupled to a DC power supply module, the transistor driving unit includes a transistor Q1, a coil of a relay J1, a resistor R1, a resistor R2, a transistor Q2, a coil of a relay J2, a resistor R3, and a resistor R4, one end of the resistor R2 is coupled to a port of the microprocessing unit, and the other end is coupled to the resistor R1, the other end of the resistor R1 is coupled to the negative electrode of the DC power supply module, the base of the transistor Q1 is coupled to the electrical connection point between the resistor R1 and the resistor R2, and the emitter is coupled to the DC power supply module. The negative electrode and collector of the module are coupled to the coil of the relay J1, and the other end of the coil of the relay J1 is coupled to the positive electrode of the DC power supply module; one end of the resistor R4 is coupled to a port of the microprocessing unit, and the other end is coupled to the resistor R3, and the other end of the resistor R3 is coupled to the negative electrode of the DC power supply module; the base of the transistor Q2 is coupled to the electrical connection point between the resistor R3 and the resistor R4, the emitter is coupled to the negative electrode of the DC power supply module, and the collector is coupled to the coil of the relay J2, and the other end of the coil of the relay J2 is coupled to the positive electrode of the DC power supply module.

[0022] Preferably, the coil of the relay J1 is connected in parallel with a protection diode D1, and the coil of the relay J2 is connected in parallel with a protection diode D2.

[0023] Preferably, the signal output module (3) comprises a resistor R9, a resistor R10, a photodiode of a photocoupler 1 / 2IC2 and a photodiode of a photocoupler 1 / 2IC3, one end of the resistor R9 is coupled to the positive electrode of the DC power supply module (1), and the other end is coupled to the positive electrode of the photodiode of the photocoupler 1 / 2IC2 to form a semiconductor resistive conduction end, one end of the resistor R10 is coupled to the positive electrode of the DC power supply module (1), and the other end is coupled to the positive electrode of the photodiode of the photocoupler 1 / 2IC3 to form another semiconductor resistive conduction end;

[0024] The signal conversion module (4) comprises a phototransistor of a photocoupler 1 / 2IC3 and a phototransistor of a photocoupler 1 / 2IC2. The collectors of the phototransistor of the photocoupler 1 / 2IC3 and the phototransistor of the photocoupler 1 / 2IC2 are respectively coupled to two input interfaces of the microprocessing unit (51), and the emitters are coupled to the negative electrode of the DC power supply module (1). The collector of the phototransistor of the photocoupler 1 / 2IC3 is also coupled to a resistor R8, and the other end of the resistor R8 is connected to a DC voltage source. The collector of the phototransistor of the photocoupler 1 / 2IC2 is also coupled to a resistor R7, and the other end of the resistor R7 is connected to the DC voltage source.

[0025] Preferably, the upper and lower limit circuit control mode switching module (7) comprises a button switch K, and the button switch K is connected in parallel with the phototransistor of the photocoupler 1 / 2IC3.

[0026] Preferably, the light indication module includes a light-emitting diode LED1, a resistor R5, a light-emitting diode LED2, and a resistor R6. The positive poles of the light-emitting diode LED1 and the light-emitting diode LED2 are coupled to a DC voltage source, and the negative poles are coupled to the resistor R5 and the resistor R6 respectively. The other ends of the resistor R5 and the resistor R6 are respectively coupled to two interfaces of the microprocessor unit.

[0027] In a second aspect of the present application, a signal amplification device for an electric contact pressure gauge is also provided.

[0028] A signal amplifying device for an electric contact pressure gauge comprises a circuit board on which a signal amplifying circuit for the electric contact pressure gauge is installed, a plastic shell and an eight-wire socket, wherein the circuit board is fixedly installed on the eight-wire socket, the plastic shell is covered on the eight-wire socket, and the circuit board is located inside the plastic shell.

[0029] In summary, the present application includes at least one of the following beneficial technical effects:

[0030] 1. Due to the control scheme of connecting the common end contact of the traditional pointer-type electric contact pressure gauge to the inductive load, the inductive load will generate a large current during the switching process, which is easy to cause the common end contact to vibrate or lose contact and cause arc burning. However, the present application adopts a resistive load to ensure that the common end contact of the pointer-type electric contact pressure gauge will not be impacted by a large current during the switching process, avoiding arcing, sintering, and melting of the mechanical contact caused by the inductive load.

[0031] 2. The conduction signal output by the signal output module of the present application is transmitted by photoelectric coupling to form photoelectric isolation, which effectively prevents interference. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a structural schematic diagram of a signal amplification circuit of an electric contact pressure gauge in an embodiment of the present application;

[0033] Figure 2 It is a wiring diagram of an electric contact pressure gauge in a signal amplification circuit of an electric contact pressure gauge in an embodiment of the present application;

[0034] Figure 3 It is an exploded schematic diagram of a signal amplifying device for an electric contact pressure gauge according to an embodiment of the present application;

[0035] Explanation of the accompanying drawings: 1. DC power supply module; 2. Electric contact pressure gauge modification trigger module; 3. Signal output module; 4. Signal conversion module; 5. Upper and lower limit circuit control module; 51. Microprocessing unit; 52. Transistor drive unit; 6. Light indication module; 7. Upper and lower limit circuit control mode switching module; 8. Circuit board; 9. Plastic shell; 10. Eight-wire socket; 11. PVC film; 12. Eight-wire plug. DETAILED DESCRIPTION

[0036] In order to enable those skilled in the art to better understand the technical solutions in this specification, the technical solutions in the embodiments of this specification will be clearly and completely described below in conjunction with the drawings in the embodiments of this specification. Obviously, the described embodiments are only part of the embodiments of this application, not all of the embodiments.

[0037] In the description of the embodiments of the present application, words such as "illustrative", "for example" or "for example" are used to indicate examples, illustrations or descriptions. Any embodiment or design described as "illustrative", "for example" or "for example" in the embodiments of the present application should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of words such as "illustrative", "for example" or "for example" is intended to present related concepts in a concrete way.

[0038] In the description of the embodiments of the present application, the term "and / or" is only a kind of association relationship describing the associated objects, indicating that there may be three kinds of relationships, for example, A and / or B, which can represent: A exists alone, B exists alone, and A and B exist at the same time. In addition, unless otherwise specified, the meaning of the term "multiple" refers to two or more. For example, multiple systems refer to two or more systems, and multiple screen terminals refer to two or more screen terminals. In addition, the terms "first" and "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the indicated technical features. Thus, the features defined as "first" and "second" can explicitly or implicitly include one or more of the features. The terms "include", "comprise", "have" and their variations all mean "including but not limited to", unless otherwise specifically emphasized.

[0039] Reference Figure 1 and Figure 2 , the embodiment of the present application discloses a signal amplification circuit of an electric contact pressure gauge, comprising a DC power supply module 1 for supplying 24V DC power, an electric contact pressure gauge modification trigger module 2, a signal output module 3, a signal conversion module 4, an upper and lower limit circuit control module 5, a light indication module 6 and an upper and lower limit circuit control mode switching module 7;

[0040] The electric contact pressure gauge modification trigger module 2 and the signal output module 3 are respectively coupled to the positive and negative poles of the DC power supply module 1 but are both in a non-conductive state. The signal conversion module 4, the light indication module 6 and the upper and lower limit circuit control mode switching module 7 are all coupled to the upper and lower limit circuit control module 5. The signal conversion module 4 and the signal output module 3 are connected via optical signals.

[0041] The DC power supply module 1 uses an AC220 / 24V switching power supply circuit composed of a DK06 chip, which is a prior art and will not be described in detail in this embodiment;

[0042] The electric contact pressure gauge modification trigger module 2 adopts a modified pointer-type electric contact pressure gauge. The specific modification method is to cut off the circuit where the upper limit contact and the lower limit contact of the pointer-type electric contact pressure gauge are located, and couple the pointer of the pointer-type electric contact pressure gauge with the negative output terminal of the DC power supply module 1 as the common terminal of the deflection pointer.

[0043] The upper limit contact and the lower limit contact are both coupled to the signal output module 3. Specifically:

[0044] The signal output module 3 includes a resistor R9, a resistor R10, a photodiode of a photocoupler 1 / 2IC2, and a photodiode of a photocoupler 1 / 2IC3. One end of the resistor R9 is coupled to the positive electrode of the DC power supply module 1, and the other end is coupled to the positive electrode of the photodiode of the photocoupler 1 / 2IC2 to form a semiconductor resistive conduction end. One end of the resistor R10 is coupled to the positive output end of the DC power supply module 1, and the other end is coupled to the positive electrode of the photodiode of the photocoupler 1 / 2IC3 to form another semiconductor resistive conduction end. The upper limit contact is coupled to the negative electrode of the photodiode of the photocoupler 1 / 2IC3, and the lower limit contact is coupled to the negative electrode of the photodiode of the photocoupler 1 / 2IC2.

[0045] Through the above settings, when the pressure of the pointer-type electric contact pressure gauge reaches the lower limit, the photodiode of the photoelectric coupler 1 / 2IC2 will be turned on, so that it will emit light and generate a light signal; when the pressure of the pointer-type electric contact pressure gauge reaches the upper limit, the photodiode of the photoelectric coupler 1 / 2IC3 will be turned on, so that it will emit light and generate a light signal;

[0046] After the signal output module 3 outputs the optical signal, it is received and converted by the signal conversion module 4 and input to the upper and lower limit circuit control module 5 for processing by the upper and lower limit circuit control module 5. Specifically:

[0047] The upper and lower limit circuit control module 5 includes a microprocessing unit 51 and a transistor driving unit 52:

[0048] The microprocessing unit 51 specifically adopts a STC15W104 single chip microcomputer, and the DC power supply module 1 is coupled to the microprocessing unit 51 through a three-terminal voltage regulator 78M05 to provide the microprocessing unit 51 with working power;

[0049] The positive output terminal of the DC power supply module 1 is coupled to a diode D3, the cathode of the diode D3 is coupled to the 1 interface of the three-terminal voltage regulator 78M05, the 2 interface of the three-terminal voltage regulator 78M05 is coupled to the micro-processing unit 51 to provide 5V DC power to the micro-processing unit 51, and the 3 interface of the three-terminal voltage regulator 78M05 is coupled to the negative electrode of the DC power supply module 1;

[0050] The signal conversion module 4 includes a phototransistor of the photocoupler 1 / 2IC3 and a phototransistor of the photocoupler 1 / 2IC2. The collector of the phototransistor of the photocoupler 1 / 2IC3 is coupled to a resistor R8, and the other end of the resistor R8 is coupled to the 2nd pin of the three-terminal regulator 78M05. The electrical connection point between the resistor R8 and the collector of the phototransistor of the photocoupler 1 / 2IC3 is coupled to an I / O interface of the microprocessing unit 51.

[0051] The collector of the phototransistor of the photocoupler 1 / 2IC2 is coupled to a resistor R7, and the other end of the resistor R7 is coupled to the 2nd pin of the three-terminal regulator 78M05; the electrical connection point between the resistor R8 and the collector of the phototransistor of the photocoupler 1 / 2IC3 is coupled to another I / O interface of the microprocessor unit 51;

[0052] The emitter of the photocoupler 1 / 2IC3 and the emitter of the photocoupler 1 / 2IC2 are both coupled to the negative electrode of the DC power supply module 1;

[0053] The transistor driving unit 52 includes a transistor Q1, a coil of a relay J1, a resistor R1, a resistor R2, a transistor Q2, a coil of a relay J2, a resistor R3, and a resistor R4. One end of the resistor R2 is coupled to an I / O interface of the microprocessing unit 51, and the other end is coupled to the resistor R1. The other end of the resistor R1 is coupled to the negative electrode of the DC power supply module 1. The base of the transistor Q1 is coupled to the electrical connection point between the resistor R1 and the resistor R2, the emitter is coupled to the negative electrode of the DC power supply module 1, and the collector is coupled to the coil of the relay J1. The other end of the coil of the relay J1 is coupled to the positive electrode of the DC power supply module 1.

[0054] One end of the resistor R4 is coupled to a port of the microprocessing unit 51, and the other end is coupled to the resistor R3, and the other end of the resistor R3 is coupled to the negative electrode of the DC power supply module 1. The base of the transistor Q2 is coupled to the electrical connection point between the resistor R3 and the resistor R4, the emitter is coupled to the negative electrode of the DC power supply module 1, and the collector is coupled to the coil of the relay J2, and the other end of the coil of the relay J2 is coupled to the positive electrode of the DC power supply module 1; the coil of the relay J1 is connected in parallel with a protection diode D1, and the coil of the relay J2 is connected in parallel with a protection diode D2. By setting the protection diode, the transistor can be protected so that it is not easily broken down by the instantaneous voltage generated when the relay coil loses power.

[0055] When the pressure expressed by the pointer-type electric contact pressure reaches the lower limit, the pointer deflects to the lower limit contact, so that the photodiode of the photocoupler 1 / 2IC2 is turned on, generating a light signal. After receiving the light signal, the photosensitive transistor of the photocoupler 1 / 2IC2 is turned on to pull down the I / O interface level of the microprocessing unit 51, so that the state switching signal becomes a low level. After receiving the state switching signal, the microprocessing unit 51 changes the base voltage of the transistor Q1 or the transistor Q2 so that the transistor Q1 or the transistor Q2 changes from the on state to the blocked state, or from the blocked state to the on state, so that the coil of the relay J1 or the relay J2 changes from energized to de-energized or from de-energized to energized, thereby changing the on-off state of the contact switch of the relay J1 or the relay J2. Similarly, when the pressure expressed by the pointer-type electric contact pressure reaches the upper limit, the photosensitive transistor of the photocoupler 1 / 2IC3 is turned on, and the principle of the change of the on-off state of the contact switch of the relay J1 or the relay J2 is similar to this.

[0056] The light indication module 6 is coupled to the microprocessing unit 51 to indicate the conduction state of the upper limit working circuit and the lower limit working circuit by luminous indication, specifically:

[0057] The light indication module 6 includes a light emitting diode LED1, a resistor R5, a light emitting diode LED2, and a resistor R6. The positive electrodes of the light emitting diode LED1 and the light emitting diode LED2 are coupled to the 2 interfaces of the three-terminal regulator 78M05 to obtain a DC voltage, and the negative electrodes are coupled to the resistor R5 and the resistor R6 respectively. The other ends of the resistor R5 and the resistor R6 are respectively coupled to the two I / O interfaces of the microprocessing unit 51.

[0058] Scenario example: When the microprocessor unit 51 turns on the transistor Q1, the voltage of the I / O interface coupled to the cathode of the light-emitting diode LED1 is adjusted to a high voltage to turn off the light-emitting diode LED1. When the transistor Q1 is not turned on, the voltage of the I / O interface coupled to the cathode of the light-emitting diode LED1 is reduced to a low voltage to light up the light-emitting diode LED1, thereby indicating the on-off state of the contact switch of the relay J1. Similarly, the light-emitting diode LED2 can also indicate the on-off state of the contact switch of the relay J2.

[0059] In order to simultaneously meet the working scenarios of lower limit start, upper limit stop (for example: oil tank refueling, water tank water filling, pressure tank pressurization) and upper limit start, lower limit stop (for example: oil tank draining, water tank draining, pressure tank decompression), the present application sets up an upper and lower limit circuit control mode switching module 7, which switches the control program of the microprocessing unit 51 to the upper limit working circuit or the lower limit working circuit, specifically:

[0060] The upper and lower limit circuit control mode switching module 7 includes a button switch K, one end of which is coupled to the negative electrode of the DC power supply module 1 , and the other end of which is coupled to the electrical connection point between the input pin of the microprocessing unit 51 and the resistor R8 .

[0061] Personnel can press the button switch K to short-circuit the phototransistor of the photocoupler 1 / 2IC3, so that the level of the I / O interface of the microprocessor unit 51 coupled to the phototransistor of the photocoupler 1 / 2IC3 is pulled down; after the microprocessor unit 51 detects that the levels of the I / O interface coupled to the phototransistor of the photocoupler 1 / 2IC3 and the I / O interface coupled to the phototransistor of the photocoupler 1 / 2IC2 are both low for multiple times within a specific time, it is determined that the levels of the I / O interface and the I / O interface coupled to the phototransistor of the photocoupler 1 / 2IC2 are simultaneously pulled down; wherein, multiple times within a specific time can be 3 times within 3 seconds; the microprocessor unit 51 will change the adjustment scheme for the opening and closing states of the contact switch of the relay J1 and the contact switch of the relay J2 after receiving the state switching signal;

[0062] For example, in this embodiment, both relay J1 and relay J2 are normally closed relays. The initial state of microprocessing unit 51 is that after receiving the state switching signal (lower limit signal) transmitted by the phototransistor of photocoupler 1 / 2IC2, the contact switch of relay J1 is adjusted to normally closed, and the contact switch of relay J2 is adjusted to normally open; after receiving the state switching signal (upper limit signal) transmitted by the phototransistor of photocoupler 1 / 2IC3, the contact switch of relay J1 is adjusted to normally open, and the contact switch of relay J2 is adjusted to normally open; and after the personnel presses the button switch K for the first time when the phototransistor of photocoupler 1 / 2IC2 is turned on, microprocessing unit 51 switches the internal control program, and the working state of microprocessing unit 51 changes to that after receiving the state switching signal transmitted by the phototransistor of photocoupler 1 / 2IC3, the contact switch of relay J2 is adjusted to normally closed, and the contact switch of relay J1 is adjusted to normally open. After receiving the state switching signal transmitted by the phototransistor of the photoelectric coupler 1 / 2IC2, the contact switch of the relay J1 is adjusted to normally open, and the contact switch of the relay J2 is adjusted to normally open; after the personnel presses the button switch K again when the phototransistor of the photoelectric coupler 1 / 2IC2 is turned on, the working state of the microprocessing unit 51 is adjusted to receive the lower limit signal and the upper limit signal, and the contact switch of the relay J1 and the contact switch of the relay J2 both remain in the normally open state; after the personnel presses the button switch K for the third time when the phototransistor of the photoelectric coupler 1 / 2IC2 is turned on, the working state of the microprocessing unit 51 is adjusted to receive the lower limit signal and the upper limit signal, and the contact switch of the relay J1 and the contact switch of the relay J2 both remain in the normally closed state, and after the personnel presses the button switch K for the fourth time when the phototransistor of the photoelectric coupler 1 / 2IC2 is turned on, the working state of the microprocessing unit 51 changes to the initial state.

[0063] Through the above settings, the present application can be started at the lower limit and stopped at the upper limit (the contact switch of relay J1 is closed after the common end of the deflection pointer deflects to the lower limit contact, and the contact switch of relay J1 is disconnected after the common end of the deflection pointer deflects to the upper limit contact) as well as started at the upper limit and stopped at the lower limit (the contact switch of relay J2 is closed after the common end of the deflection pointer deflects to the upper limit contact, and the contact switch of relay J2 is disconnected after the common end of the deflection pointer deflects to the lower limit contact).

[0064] For example: when the equipment is filling oil, when the pointer-type electric contact pressure gauge indicates that the oil volume has reached the lower limit, the microprocessing unit 51 controls the contact switch of the relay J1 to close and fill the oil. When the pointer-type electric contact pressure gauge indicates that the oil volume has reached the upper limit, the microprocessing unit 51 controls the contact switch of the relay J1 to disconnect and complete the oil filling. During this process, the contact of the relay J2 remains disconnected. When the equipment is draining oil, when the phototransistor of the photocoupler 1 / 2IC2 is turned on, the personnel presses the button switch K, and the container starts to fill oil. When the pointer-type electric contact pressure gauge indicates that the oil volume has reached the upper limit, the microprocessing unit 51 controls the contact switch of the relay J2 to close and drain the oil. When the pointer-type electric contact pressure gauge indicates that the oil volume has reached the lower limit, the microprocessing unit 51 controls the contact switch of the relay J2 to disconnect and complete the oil discharge. During this process, the contact of the relay J1 remains disconnected. This multifunctional and intelligent output signal mode brings great convenience to the design of the automatic control circuit of the press machine tool equipment.

[0065] Reference Figure 3 The present application also provides an electric contact pressure gauge signal amplification device, comprising a circuit board 8 on which the above-mentioned electric contact pressure gauge signal amplification circuit is installed, a PVC film 11, a plastic shell 9 and an eight-wire socket 10, the circuit board 8 is fixedly installed on the eight-wire socket 10, the bottom of the eight-wire socket 10 is adapted to the mounting rail in the electric control box to facilitate the eight-wire socket 10 to be installed on the mounting rail, the circuit board 8 includes a main circuit board 8, a power supply circuit board 8 and a plug connection circuit board 8, the plug connection circuit board 8 is electrically connected to the eight-wire socket 10 through an eight-wire plug 12, and the eight-wire The plug 12 is an eight-pin welding plug, wherein the DC power supply module 1 is installed on the power circuit board 8, the electric contact pressure gauge transformation trigger module 2, the signal output module 3, the signal conversion module 4, the upper and lower limit circuit control module 5, the light indication module 6 and the upper and lower limit circuit control mode switching module 7 are all installed on the main circuit board 8, the plastic shell 9 is covered on the eight-wire socket 10 and fixedly connected to the eight-wire socket 10, the circuit board 8 is located in the plastic shell 9, the PVC film 11 is applied to the surface of the plastic shell 9, and the plastic shell 9 has a small button hole for the button switch K to extend out.

[0066] The above is only an exemplary embodiment of the present disclosure, and the scope of the present disclosure cannot be limited thereto. That is, any equivalent changes and modifications made according to the teachings of the present disclosure are still within the scope of the present disclosure. After considering the specification and practicing the disclosure here, those skilled in the art will easily think of other embodiments of the present disclosure. This application is intended to cover any modification, use or adaptation of the present disclosure, which follows the general principles of the present disclosure and includes common knowledge or customary technical means in the technical field not recorded in the present disclosure. The description and examples are only regarded as exemplary, and the scope and spirit of the present disclosure are defined by the claims.

Claims

1. A signal amplification circuit for an electric contact pressure gauge, characterized in that: include: A DC power supply module (1), used for supplying DC power; The electric contact pressure gauge modification trigger module (2) has a deflection pointer common end for deflecting when the electric contact pressure gauge reaches the upper and lower limits, and the deflection pointer common end is coupled to the negative pole of the DC power supply module (1); A signal output module (3) coupled to the positive electrode of the DC power supply module (1), having two semiconductor resistive conduction terminals for electrically contacting the deflection contact terminals, and for outputting different conduction signals according to the semiconductor resistive conduction terminals contacted by the deflection contact terminals; A signal conversion module (4), used for receiving a conduction signal and outputting a state switching signal; The upper and lower limit circuit control module (5) is coupled to the signal conversion module (4) and is used to receive a state switching signal and control the upper limit working circuit or the lower limit working circuit to be turned on or off according to the state switching signal.

2. The electric contact pressure gauge signal amplification circuit according to claim 1, characterized in that: Also includes: The light indication module (6) is coupled to the upper and lower limit circuit control module (5) and is used to provide a light indication of the conduction state of the upper limit working circuit and the lower limit working circuit.

3. The electric contact pressure gauge signal amplification circuit according to claim 1, characterized in that: The upper and lower limit circuit control module (5) comprises: A microprocessing unit (51), coupled to the signal conversion module (4), configured to receive a state switching signal and output a driving level; The transistor driving unit (52) is coupled to the microprocessing unit (51) and is used to control the on / off of the contact switch of the relay J2 of the upper limit working circuit and the contact switch of the relay J1 of the lower limit working circuit according to the driving level.

4. The electric contact pressure gauge signal amplification circuit according to claim 3, characterized in that: Also includes: The upper and lower limit circuit control mode switching module (7) is coupled to the microprocessing unit (51) and is used to switch the control program of the microprocessing unit (51) for the upper limit working circuit or the lower limit working circuit.

5. The electric contact pressure gauge signal amplification circuit according to claim 3, characterized in that: The microprocessing unit (51) adopts a single chip microcomputer. The microprocessing unit (51) is coupled to a DC power supply module (1). The transistor driving unit (52) comprises a transistor Q1, a coil of a relay J1, a resistor R1, a resistor R2, a transistor Q2, a coil of a relay J2, a resistor R3, and a resistor R4. One end of the resistor R2 is coupled to a port of the microprocessing unit (51), and the other end is coupled to the resistor R1. The other end of the resistor R1 is coupled to the negative electrode of the DC power supply module (1). The base of the transistor Q1 is coupled to the electrical connection point between the resistor R1 and the resistor R2, and the emitter is coupled to the DC power supply module (1). The negative electrode and collector of the module (1) are coupled to the coil of the relay J1, and the other end of the coil of the relay J1 is coupled to the positive electrode of the DC power supply module (1); one end of the resistor R4 is coupled to a port of the microprocessing unit (51), and the other end is coupled to the resistor R3, and the other end of the resistor R3 is coupled to the negative electrode of the DC power supply module (1); the base of the transistor Q2 is coupled to the electrical connection point between the resistor R3 and the resistor R4, the emitter is coupled to the negative electrode of the DC power supply module (1), and the collector is coupled to the coil of the relay J2, and the other end of the coil of the relay J2 is coupled to the positive electrode of the DC power supply module (1).

6. The electric contact pressure gauge signal amplification circuit according to claim 5, characterized in that: The coil of the relay J1 is connected in parallel with a protection diode D1 , and the coil of the relay J2 is connected in parallel with a protection diode D2 .

7. The electric contact pressure gauge signal amplification circuit according to claim 4, characterized in that: The signal output module (3) comprises a resistor R9, a resistor R10, a photodiode of a photocoupler 1 / 2IC2 and a photodiode of a photocoupler 1 / 2IC3, one end of the resistor R9 is coupled to the positive electrode of the DC power supply module (1), and the other end is coupled to the positive electrode of the photodiode of the photocoupler 1 / 2IC2 to form a semiconductor resistive conduction end, and one end of the resistor R10 is coupled to the positive electrode of the DC power supply module (1), and the other end is coupled to the positive electrode of the photodiode of the photocoupler 1 / 2IC3 to form another semiconductor resistive conduction end; The signal conversion module (4) comprises a phototransistor of a photocoupler 1 / 2IC3 and a phototransistor of a photocoupler 1 / 2IC2. The collectors of the phototransistor of the photocoupler 1 / 2IC3 and the phototransistor of the photocoupler 1 / 2IC2 are respectively coupled to two input interfaces of the microprocessing unit (51), and the emitters are coupled to the negative electrode of the DC power supply module (1). The collector of the phototransistor of the photocoupler 1 / 2IC3 is also coupled to a resistor R8, and the other end of the resistor R8 is connected to a DC voltage source. The collector of the phototransistor of the photocoupler 1 / 2IC2 is also coupled to a resistor R7, and the other end of the resistor R7 is connected to the DC voltage source.

8. The electric contact pressure gauge signal amplifying circuit according to claim 7, characterized in that: The upper and lower limit circuit control mode switching module (7) comprises a button switch K, and the button switch K is connected in parallel with the photosensitive transistor of the photoelectric coupler 1 / 2IC3.

9. The electric contact pressure gauge signal amplification circuit according to claim 2, characterized in that: The light indication module (6) comprises a light emitting diode LED1, a resistor R5, a light emitting diode LED2 and a resistor R6. The positive electrodes of the light emitting diode LED1 and the light emitting diode LED2 are coupled to a DC voltage source, and the negative electrodes are coupled to the resistor R5 and the resistor R6 respectively. The other ends of the resistor R5 and the resistor R6 are coupled to two interfaces of the microprocessing unit (51) respectively.

10. A signal amplifying device for an electric contact pressure gauge, characterized in that: It comprises a circuit board (8) on which an electric contact pressure gauge signal amplifying circuit as claimed in any one of claims 1 to 9 is installed, a plastic shell (9) and an eight-wire socket (10), wherein the circuit board (8) is fixedly installed on the eight-wire socket (10), the plastic shell (9) is covered on the eight-wire socket (10), and the circuit board (8) is located inside the plastic shell (9).

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