CN111953322A

CN111953322A - Drive circuit of high-speed switch valve

Info

Publication number: CN111953322A
Application number: CN202010891968.3A
Authority: CN
Inventors: 李娜娜; 白彩盛
Original assignee: Lanzhou University of Technology; Lanzhou Modern Vocational College
Current assignee: Lanzhou University of Technology; Lanzhou Modern Vocational College
Priority date: 2020-08-31
Filing date: 2020-08-31
Publication date: 2020-11-17
Anticipated expiration: 2040-08-31
Also published as: CN111953322B

Abstract

The invention relates to a drive circuit of a high-speed switch valve, a current detection circuit respectively leads a low-voltage trigger circuit to be conducted and a voltage-stabilizing tube to be broken down when the current is low or high, an in-place error detection circuit adopts high and low levels output by a hysteresis comparison circuit to judge the in-place error, when the in-place error is higher than an allowable error, a coil of a drive relay K1 is driven to be electrified, a pulse duty ratio modulation circuit adopts a Schmidt NAND gate circuit to modulate detected PWM pulses when the current is low, the pulse duty ratio is changed, the switching speed of the drive tube is improved by changing the driving force, the modulated PWM pulses are directly or under the control of a switch valve in-place detection signal when the coil of the relay K1 is not electrified, the pulse number modulation circuit changes the pulse number to play a role in correcting the switch in-place deviation, the switching speed of the drive tube is further improved by differentiation, when the current is high, corresponding current limiting, the stability of the high-speed switch valve in long-term use is ensured.

Description

Drive circuit of high-speed switch valve

Technical Field

The invention relates to the technical field of water affairs, in particular to a driving circuit of a high-speed switch valve.

Background

Compared with the common switch valve, the high-speed switch valve has higher switching speed, the switching time has close relation with a drive circuit thereof, generally, a PWM pulse output by a PWM generating source (CPU) is adopted, the power of a drive tube is amplified, the drive force is improved, then the high voltage is controlled to be added to a valve core of the high-speed switch valve to complete the switching action, a larger current is provided at the moment of opening the switch valve, the current is reduced to a lower holding current after the switching action is completed, the switching speed can be improved, the electromagnetic heating value in a steady state can be reduced, an electromagnet can effectively work for a long time, under the premise that the high voltage is stable and the valve core structure and the electromagnetic structure parameters of the high-speed switch valve are fixed, the setting of the drive signal can necessarily obtain higher switching frequency and stability, however, the high voltage is dynamically changed, and the valve core structure and the electromagnetic structure parameters of the high-speed switch valve have different, Offset, etc. to ensure the switching frequency and stability of the high-speed switching valve, dynamic compensation of the driving signal is required.

Disclosure of Invention

In view of the above situation, in order to overcome the defects in the prior art, an object of the present invention is to provide a driving circuit for a high-speed switching valve, which can dynamically compensate a driving signal according to a current signal collected on a valve core of the high-speed switching valve and a switch valve in-place detection signal, thereby ensuring the frequency and stability of the high-speed switching valve.

The technical scheme for solving the problem is that the device comprises a PWM pulse receiving circuit, a current detection circuit, an in-place error detection circuit, a pulse number modulation circuit and a pulse duty ratio modulation circuit, and is characterized in that the PWM pulse receiving circuit detects PWM pulses by adopting rectification and amplification and enters the pulse duty ratio modulation circuit;

when the current is low or high, the current detection circuit respectively conducts the low-voltage trigger circuit and breaks down the voltage regulator tube, and a current signal enters the pulse duty ratio modulation circuit;

the in-place error detection circuit judges the in-place error by adopting the high and low levels output by the hysteresis comparison circuit, and drives the coil of the relay K1 to be electrified when the in-place error is higher than the allowable error;

the pulse duty ratio modulation circuit modulates the detected PWM pulse by adopting a Schmidt NAND gate IC1 when the current is low, changes the pulse duty ratio, improves the switching speed of the driving tube by changing the driving force, after the PWM pulse is directly changed by a pulse number modulation circuit when a relay K1 coil is not electrified or when a relay K1 coil is electrified after the pulse number is changed by the pulse number modulation circuit, the switching speed of the driving tube is further improved by a relay K1 normally closed contact K1-2, a resistor R7 and a capacitor C5 which are connected in parallel, when the current is high, the resistance value of a field effect tube T1 which is used as a current limiting resistor is changed, and the current is correspondingly limited and then added to the driving tube;

the pulse number modulation circuit directly adds one path of the received modulated PWM pulse to an OR gate IC4, the other path of the modulated PWM pulse is added to an OR gate IC4 after controllable delay, the OR gate IC4 superposes two waveforms to change the number of the pulse, wherein the time of the controllable delay is controlled by a switch valve in-place detection signal.

The invention has the beneficial effects that: the Schmidt NAND gate circuit which is formed by taking a NAND Schmidt trigger as a core is adopted, when the detected current applied to the valve core of the high-speed switch valve is low or high, the low-voltage trigger circuit is conducted, the voltage stabilizing tube is broken down, the detected PWM pulse is modulated when the current is low, the pulse duty ratio is changed, the switching speed of the driving tube is improved by changing the driving force, and when the current is not low (normal or high), the photoelectric coupler and the triode Q2 are in a turn-off state, and the modulation pulse with unchanged frequency is output;

after the PWM pulse is modulated, when the coil of the relay K1 is not electrified, the pulse number is changed directly or when the coil of the relay K1 is electrified through a pulse number modulation circuit, one path of the PWM pulse is directly added to an OR gate IC4 after specific modulation, the other path of the PWM pulse is added to an OR gate IC4 after controllable delay, the OR gate IC4 superposes two waveforms, so that the pulse number is changed, wherein the time of the controllable delay is controlled by a switch valve in-place error signal to play a role in correcting switch in-place deviation, the switching speed of a driving tube is further improved through a differential circuit formed by a relay K1 normally closed contact K1-2, a resistor R7 and a capacitor C5 which are connected in parallel, meanwhile, when the current applied to a high-speed switch valve core is high, a voltage stabilizing tube ZW1 is reversely broken down, the voltage is converted through a resistor R11 and then is added to a grid electrode of a field effect tube T1, the leakage source resistance value of the field effect tube T1 is changed, and then the current, the stability of the high-speed switch valve in long-term use is guaranteed, compared with the situation that the current is collected and the in-place deviation is fed back to a PWM generating source (CPU), the PWM generating source (CPU) has higher corresponding speed through calculation analysis and PWM pulse re-output, and can be more suitable for the current and in-place deviation caused by instantaneous and dynamically-changed high voltage.

Drawings

Fig. 1 is a schematic diagram of a PWM pulse receiving circuit according to the present invention.

Fig. 2 is a schematic diagram of a current detection circuit of the present invention.

FIG. 3 is a schematic diagram of the in-place error detection circuit of the present invention.

Fig. 4 is a schematic diagram of a pulse number modulation circuit according to the present invention.

Fig. 5 is a schematic diagram of a pulse duty cycle modulation circuit of the present invention.

Detailed Description

The foregoing and other aspects, features and advantages of the invention will be apparent from the following more particular description of embodiments of the invention, as illustrated in the accompanying drawings in which reference is made to figures 1 to 5. The structural contents mentioned in the following embodiments are all referred to the attached drawings of the specification.

Exemplary embodiments of the present invention will be described below with reference to the accompanying drawings.

The first embodiment is that the driving circuit of the high-speed switch valve comprises a PWM pulse receiving circuit, a current detection circuit, an in-place error detection circuit, a pulse number modulation circuit and a pulse duty ratio modulation circuit, wherein the PWM pulse receiving circuit adopts a photoelectric coupler for receiving, a triode for reversing and an operational amplifier for amplifying and detecting PWM pulses and the PWM pulses enter the pulse duty ratio modulation circuit;

when the current detection circuit is applied to the valve core of the high-speed switch valve, the low-voltage trigger circuit is conducted, one path of the low-voltage trigger circuit conducts the thyristor VTL1, the voltage is converted by the resistor R11 and then is applied to the negative electrode of the varactor DC1 of the pulse duty ratio modulation circuit, the other path of the low-voltage trigger circuit conducts the triode Q2, and simultaneously the input end of the photoelectric coupler OP1 generates voltage difference so as to change the pulse duty ratio, when the current applied to the valve core of the high-speed switch valve is high, the voltage stabilizing tube ZW1 is reversely broken down, the voltage is converted by the resistor R11 and then is applied to the grid electrode of the field effect tube T1 in the pulse duty ratio modulation circuit, and then,

the in-place error detection circuit adopts high and low levels output by the hysteresis comparison circuit to judge an in-place error, a difference value between a high-speed switch valve real-time in-place signal detected by a specific displacement sensor and a standard in-place signal is added to the in-phase input end of an operational amplifier AR2 through a voltage regulator tube Z2, the absolute value of the difference value and the opposite phase input end allow in-place error signals, when the difference value is higher than the allowed in-place error, the operational amplifier AR2 outputs a low level, a triode Q4 is switched on, a coil of a driving relay K1 is electrified, normally open contacts K1-1 and K1-3 are closed, and a normally closed contact K1;

the pulse duty ratio modulation circuit adopts Schmidt NAND gate IC1 to modulate the detected PWM pulse when the current is low, change the pulse duty ratio, improve the switching speed of the driving tube by changing the driving force, when the current is not low (normal or high), the photoelectric coupler and the triode Q2 are in the off state, output modulation pulse with invariable frequency, the modulated PWM pulse is directly when the coil of the relay K1 is not electrified or changes the pulse number by the pulse number modulation circuit when the coil of the relay K1 is electrified, wherein the time of controllable delay is controlled by the switch valve in-place error signal to play the role of correcting the switch in-place deviation, the switching speed of the driving tube is further improved by the normally closed contact K1-2 of the relay K1, the resistor R7 and the capacitor C5 which are connected in parallel, when the current is high, the current limiting field effect transistor T1 which is used as the resistor is changed, and is added to the driving tube after corresponding current limiting, the current is correspondingly limited and then is added to the driving tube, the stability of the high-speed switch valve in long-term use is ensured, compared with the situation that the current is collected and the deviation in place is fed back to a PWM (pulse width modulation) generating source (CPU), the PWM generating source (CPU) has higher corresponding speed through calculation analysis and PWM pulse re-output, and can be more suitable for the current and deviation in place caused by instantaneous and dynamically changed high voltage;

the pulse number modulation circuit directly adds one path of the received modulated PWM pulse to an OR gate IC4, the other path of the modulated PWM pulse is added to an OR gate IC4 after controllable delay, the OR gate IC4 superposes two waveforms to change the number of the pulse, wherein the time of the controllable delay is controlled by an on-off valve in-place error signal.

In the second embodiment, based on the first embodiment, the pulse number modulation circuit directly adds one path of the received modulated PWM pulse to the pin a of the or gate IC4, and the other path of the modulated PWM pulse is added to the pin B of the or gate IC4 after controllable delay through a delay circuit composed of a capacitor C10, a resistor R16, a resistor R17, a capacitor C10, a varactor diode DC2, a nand gate IC2 and a not gate IC3, the time of the controllable delay is controlled by a switch valve in-place error signal, or the gate IC4 superposes two waveforms to change the number of pulses, thereby ensuring the switch of the high-speed switch valve to be in place, including a relay K1 normally open contact K1-1, a relay K1 normally open contact K1-3, the left end of the normally open contact K1-1 is connected with a switch valve in-place detection signal, the left end of the relay K1 normally open contact K1-3 is connected with the normally open pin Y of the schmidt gate IC1C, and the right end of the relay K1 is connected with the right end of the capacitor C57324C 24C, Pin a of an or gate IC4, the other end of a capacitor C10 is connected to one end of a ground resistor R16 and pin 2 of an nand gate IC2 respectively, pin 3 of an nand gate IC2 is connected to one end of a capacitor C11 respectively, the other end of a capacitor C11 is connected to one end of a resistor R17, the right end of a normally open contact K1-1 of a relay K1 respectively, the negative electrode of a varactor DC2, the other end of the resistor R17 is connected to +5V, the positive electrode of the varactor DC2 is connected to pin 1 of a not gate IC3, pin 2 of the not gate IC3 is connected to pin B of an or gate IC4, and pin Y of a gate IC4 is connected to the right end of a normally closed contact K1-2 of a relay K1.

In a third embodiment, on the basis of the first embodiment, the pulse duty ratio modulation circuit adopts a schmitt nand gate circuit composed of four 2 input terminals of a non-schmitt trigger IC1 (IC 1A, IC1B and IC 1C) with the model number HC132, a resistor R4, a resistor R6, a resistor R12, capacitors C3 and C4, a capacitor C6 and a capacitor C7, a diode D3-a diode D5, a photocoupler OP1 and a triode Q2, modulates detected PWM pulses at low current to change the pulse duty ratio, and increases the switching speed of the driving tube by changing the driving force, specifically, the PWM pulses output by the PWM pulse receiving circuit to be received by the non-schmitt trigger IC1A, i.e. modulates high levels in the PWM pulses, the modulation frequency is determined by the values of a resistor R4 and a capacitor C3, the charging and discharging periods of the resistor R4 and the capacitor C3 are set as PWM pulse periods, and the pulse frequency is not changed, directly applied to pin A of NAND Schmitt trigger IC1A, NAND Schmitt trigger IC1B receives PWM pulse output by the PWM pulse receiving circuit, and modulates the PWM pulse, the modulation frequency is determined by the values of resistor R12, capacitor C3 and varactor DC1 which are connected in series, namely when the current is low, one path conducts thyristor VTL1, the voltage is determined by the negative pole voltage of varactor DC1 after being converted by resistor R11, the other path conducts triode Q2 and simultaneously generates voltage difference at the input end of photoelectric coupler OP1, the modulation pulse output by NAND Schmitt trigger IC1B is conducted by conducting triode Q2, and then is detected by capacitors C7 and C8 and diodes D4 and D5 and then is applied to pin B of NAND Schmitt trigger IC1C, at this time, the low level voltage difference generated at the input end of OP1 is conducted, and the low level voltage difference can not be transmitted to pin B of NAND Schmitt trigger IC1C through diode D3, the switching frequency of the high-speed switching valve is improved by carrying out NAND logical operation on the NAND Schmitt trigger IC1C to output modulation pulses, the switching frequency of the high-speed switching valve is further improved by changing the duty ratio of the pulses to adjust the current, when the current is not low (normal or high), the NAND Schmitt trigger IC1A and IC1B generate the same modulation pulses, a photoelectric coupler and a triode Q2 are in an off state, +5V is added to a pin B of the NAND Schmitt trigger IC1C, the NAND Schmitt trigger IC1C outputs modulation pulses with unchanged frequency, after the PWM pulses are modulated, when a relay K1 coil is not electrified, the number of the pulses is directly changed through a pulse number modulation circuit or when a relay K1 coil is electrified, namely, after the switching offset is corrected, the switching speed of the driving tube is further improved through a differential circuit consisting of a relay K1 normally closed contact K1-2, a resistor R7 and a capacitor C5 which are connected in parallel, and when the current is high when the high-speed switching valve core of the, the voltage stabilizing tube ZW1 is reversely broken down, the voltage is converted by a resistor R11 and then is added to a grid of a field effect tube T1, the resistance between a drain and a source of the field effect tube T1 is changed, namely the voltage is added to a driving tube after corresponding current limiting, the electromagnetic heating value is reduced, an electromagnet can effectively work for a long time, and the stability of long-term use of a high-speed switching valve is ensured The cathode of a thyristor VTL1, a pin Y of a Schmidt NAND gate IC1B is connected with an emitter of a triode Q2, a collector of a triode Q2 is connected with one end of a capacitor C7, the other end of the capacitor C7 is respectively connected with an anode of a diode D4 and a cathode of a diode D5, an anode of a diode D5 is connected with the ground, a cathode of a diode D4 is respectively connected with one end of a ground capacitor C8, a pin B of the Schmidt NAND gate IC1C and a cathode of a diode D3, an anode of a diode D9 is respectively connected with a pin 4 of a photocoupler OP1 and one end of a resistor R5, the other end of a resistor R5 is connected with a power supply +5V, a pin 3 of the photocoupler OP1 is connected with a resistor R6, a pin 1 of the photocoupler OP1 is connected with a power supply +5V, a pin Y of the Schmidt NAND gate IC1C is respectively connected with a left normally-closed contact of a relay K1-1, and a right end of the relay K1-36, One end of a capacitor C5, the other end of a resistor R7 are respectively connected with the other end of the capacitor C5 and the drain of a field effect transistor T1, the other end of the resistor R7 is connected with a driving tube, the source of the field effect transistor T1 is respectively connected with one end of a grounding resistor R8 and one end of a grounding capacitor C6, and the grid of the field effect transistor T1 is connected with the negative electrode of a grounding electrolytic capacitor E1.

In a fourth embodiment, based on the first embodiment, the PWM pulse receiving circuit uses a photocoupler OP2 to receive the PWM pulse output by the PWM generator (CPU), reverses the direction and eliminates the jitter interference of the rising edge and the falling edge, and then reverses the direction by a transistor Q4, and then enters an amplifier composed of an operational amplifier AR1, a resistor R1, a resistor R2, and a resistor R21 to amplify and compensate the attenuation in signal transmission, and enters a pulse duty cycle modulation circuit, which includes a resistor R3, one end of the resistor R3 is connected to the PWM pulse output by the PWM generator (CPU), the other end of the resistor R3 is connected to a pin 1 of the photocoupler OP2, one end of a capacitor C1, the other end of the capacitor C1 is connected to the pin 2 of the photocoupler OP2, a pin 4 of the photocoupler OP2 is connected to one end of a resistor R20 and the base of the transistor Q4, a pin 3 of the photocoupler 2 is connected to the ground, and an emitter of the transistor Q4 is connected, The other end of the resistor R20 is connected with a power supply +5V, the collector of the triode Q4 is connected with one end of a grounding resistor R21 and the non-inverting input end of the operational amplifier AR1, the inverting input end of the operational amplifier AR1 is respectively connected with one end of a grounding resistor R1 and one end of a resistor R2, and the output end of the operational amplifier AR1 and the other end of the resistor R2 are used for outputting signals by a pulse receiving circuit;

when the current detection circuit is applied to a valve core of a high-speed switch valve (which can be detected by a current sensor), namely when the current is low after being converted into voltage by a resistor R11, a low-voltage trigger circuit consisting of a triode Q1, a resistor R9 and a resistor R10 is conducted, one way of the low-voltage trigger circuit conducts a thyristor VTL1, the voltage converted by a resistor R11 is applied to the negative electrode of a varactor diode DC1 of a pulse duty ratio modulation circuit, the other way conducts a triode Q2 and simultaneously generates a voltage difference at the input end of a photoelectric coupler OP1 so as to change the pulse duty ratio, when the current applied to the valve core of the high-speed switch valve is high, a voltage stabilizing tube ZW1 is reversely broken down, the voltage converted by a resistor R11 is applied to the grid electrode of a field effect tube T1 in the pulse duty ratio modulation circuit, corresponding current limiting is performed and then applied to a driving tube, the driving tube comprises an inductor L1, the left end of the inductor L1 is connected with a detected current signal in, the other end of the resistor R11 is respectively connected with one end of a resistor R10, the anode of a thyristor VTL1, the cathode of a voltage regulator tube ZW1 and the base of a triode Q1, the anode of the voltage regulator tube ZW1 is connected with the grid of a field effect tube T1, the emitter of the triode Q1 is connected with one end of the resistor R9, the other end of the resistor R10 and the other end of the resistor R9 are connected with +1V, and the collector of the triode Q1 is respectively connected with the control electrode of the thyristor VTL1, the pin 2 of a photoelectric coupler OP1 and the base of the triode Q2;

the in-place error detection circuit adopts a high-low level output by a hysteresis comparison circuit consisting of an operational amplifier AR2, a resistor R13, a resistor R14 and a triode Q3 to judge the in-place error, the difference value between a high-speed switch valve real-time in-place signal and a standard in-place signal detected by a specific displacement sensor and the absolute value of the difference value (detected by the displacement sensor, a subtracter obtains the difference value and an inverter further obtains the absolute value of the difference value, which is the prior art and is not described in detail herein) is added to the non-inverting input end of the operational amplifier AR2 through a voltage-stabilizing tube Z2, the non-inverting input end allows the in-place error signal, when the in-place error is higher than the allowable in-place error, the operational amplifier AR2 outputs a low level, the triode Q4 is conducted to drive a coil of a relay K1 to be electrified, normally-open contacts K1-1 and K1-3 are closed, a normally-closed contact K1-, the positive electrode of a voltage-stabilizing tube ZW2 is connected with the non-inverting input end of an operational amplifier AR2, the inverting input end of the operational amplifier AR2 is respectively connected with one end of a resistor R13, one end of a grounding resistor R14 and the emitter of a triode Q3, the other end of the resistor R13 and the collector of a triode Q3 are connected with a switch valve standard in-place signal, the output end of the operational amplifier AR2 is respectively connected with one end of a resistor R15 and the base of a triode Q3, the other end of the resistor R15 is respectively connected with one end of a grounding capacitor C9 and the base of a triode Q4, the emitter of the triode Q4 is connected with +5V, the collector of a triode Q4 is respectively connected with the upper end of a coil of a relay K1 and the negative electrode of a diode D6, and the lower end of.

When the invention is used, the PWM pulse receiving circuit adopts a photoelectric coupler OP2 to receive PWM pulses output by a PWM generating source (CPU), reverses and eliminates the jitter interference of a rising edge and a falling edge, then the PWM pulses are reversed by a triode Q4, enter an amplifier for amplification, compensate the attenuation in signal transmission, enter a pulse duty ratio modulation circuit, adopt a Schmidt NAND gate circuit which is formed by taking a NAND Schmidt trigger as a core, respectively lead a low-voltage trigger circuit to be conducted and a voltage stabilizing tube to be broken down when the current of a current detection circuit is low or high, modulate the detected PWM pulses when the current is low, change the pulse duty ratio, improve the switching speed of a driving tube by changing a driving force, when the current is not low (normal or high), the photoelectric coupler and the triode Q2 are in a turn-off state, output modulation pulses with unchanged frequency, the PWM pulses directly change the number of the pulses when a relay K1 coil is not electrified or when the relay K1 coil is electrified after modulation circuits change the number of the pulses, the PWM pulse after specific modulation is directly added to an OR gate IC4 in one path, the other path is added to an OR gate IC4 after controllable delay, the number of the pulses is changed by superposing two waveforms, wherein the time of the controllable delay is controlled by a switch valve in-place error signal (specifically, the high and low levels output by a hysteresis comparison circuit are adopted to judge the in-place error, when the in-place error is higher than the allowable in-place error, an operational amplifier AR2 outputs the low level, a triode Q4 is conducted, a coil of a driving relay K1 is electrified, a normally open contact K1-1, a K1-3 is closed, a normally closed contact K1-2 is disconnected), the switch in-place deviation is corrected, the switching speed of a driving tube is further improved through a differential circuit consisting of a relay K1 normally closed contact K1-2, a resistor R7 and a capacitor C5 which are connected in parallel, and a voltage stabilizing tube ZW1 is reversely broken when the current applied to a valve core of a high-speed switch valve, the voltage converted by the resistor R11 is added to the grid of the field effect transistor T1, the resistance value between the drain and the source of the field effect transistor T1 is changed, corresponding current limiting is carried out and then the current is added to the driving tube, and the stability of the high-speed switch valve in long-term use is ensured.

Claims

1. A drive circuit of a high-speed switch valve comprises a PWM pulse receiving circuit, a current detection circuit, an in-place error detection circuit, a pulse number modulation circuit and a pulse duty ratio modulation circuit, and is characterized in that the PWM pulse receiving circuit adopts rectification and amplification to detect PWM pulses and the PWM pulses enter the pulse duty ratio modulation circuit;

2. The driving circuit of a high-speed switch valve as claimed in claim 1, wherein the pulse number modulation circuit comprises a relay K1 normally open contact K1-1, a relay K1 normally open contact K1-3, a left end of a relay K1 normally open contact K1-1 is connected with a switch valve in-place detection signal, a left end of a relay K1 normally open contact K1-3 is connected with a pin Y of a Schmidt NAND gate IC1C, a right end of a relay K1 normally open contact K1-3 is connected with one end of a capacitor C10 or a pin A of a gate IC4, the other end of a capacitor C10 is connected with one end of a grounding resistor R16 and a pin 2 of a NAND gate IC2, a pin 3 of a NAND gate IC2 is connected with one end of a capacitor C11, the other end of a capacitor C11 is connected with one end of a resistor R17, a right end of a relay K1 normally open contact K1-1, and a negative electrode of a varactor IC2, the other end of the resistor R17 is connected with +5V of a power supply, the anode of the variable capacitance diode DC2 is connected with a pin 1 of the NOT gate IC3, a pin 2 of the NOT gate IC3 is connected with a pin B of the OR gate IC4, and a pin Y of the OR gate IC4 is connected with the right end of a normally closed contact K1-2 of the relay K1.

3. The driving circuit of a high-speed switch valve as claimed in claim 1, wherein said pulse duty cycle modulation circuit comprises Schmidt NAND gate IC1, pin A of Schmidt NAND gate IC1A and pin A of IC1B are both connected to the output terminal of operational amplifier AR1, pin B of Schmidt NAND gate IC1A is connected to one end of resistor R4 and one end of grounding capacitor C3, pin Y of Schmidt NAND gate IC1A is connected to the other end of resistor R4 and pin A of Schmidt NAND gate IC1C, pin B of Schmidt NAND gate IC1B is connected to one end of resistor R12 and the positive electrode of varactor DC1, the negative electrode of varactor DC1 is connected to one end of grounding capacitor C4 and the cathode of thyristor VTL1, pin Y of Schmidt NAND gate IC1B is connected to the emitter of triode Q2, and the collector of Q2 is connected to the collector of capacitor C7, the other end of the capacitor C7 is respectively connected with the anode of a diode D4 and the cathode of a diode D5, the anode of a diode D5 is connected with the ground, the cathode of a diode D4 is respectively connected with one end of a grounded capacitor C8, the pin B of a Schmidt NAND gate circuit IC1C and the cathode of a diode D3, the anode of a diode D3 is respectively connected with the pin 4 of a photoelectric coupler OP1 and one end of a resistor R5, the other end of the resistor R5 is connected with a power supply +5V, the pin 3 of the photoelectric coupler OP1 is connected with the ground through a resistor R6, the pin 1 of the photoelectric coupler OP1 is connected with the power supply +5V, the pin Y of the Schmidt NAND gate IC1C is connected with the left end of a normally closed contact K1-2 of a relay K1, the right ends of the normally closed contact K1-2 of the resistor K1 are respectively connected with one end of a resistor R7 and one end of a capacitor C5, the other end of the drain of the resistor R5 is respectively connected with the, the source of the fet T1 is connected to one end of the ground resistor R8 and one end of the ground capacitor C6, respectively, and the gate of the fet T1 is connected to the negative electrode of the ground electrolytic capacitor E1.

4. A drive circuit of a high-speed switching valve according to claim 1, the PWM pulse receiving circuit comprises a resistor R3, one end of a resistor R3 is connected with PWM pulses output by a PWM generating source (CPU), the other end of the resistor R3 is respectively connected with one end of a pin 1 of a photoelectric coupler OP2 and one end of a capacitor C1, the other end of a capacitor C1 is connected with a pin 2 of a photoelectric coupler OP2, a pin 4 of the photoelectric coupler OP2 is respectively connected with one end of a resistor R20 and a base of a triode Q4, a pin 3 of the photoelectric coupler OP2 is connected with the ground, an emitter of a triode Q4 and the other end of a resistor R20 are connected with a power supply +5V, a collector of a triode Q4 is connected with one end of a grounding resistor R21 and a non-inverting input end of an operational amplifier AR1, an inverting input end of the operational amplifier AR1 is respectively connected with one end of a grounding resistor R1 and one end of a resistor R2, and the output end of the operational amplifier AR1 and;

the current detection circuit comprises an inductor L1, the left end of the inductor L1 is connected with a detected current signal in the solenoid coil of the switching valve, the right end of the inductor L1 is connected with one end of a resistor R11, the other end of the resistor R11 is respectively connected with one end of a resistor R10, the anode of a thyristor VTL1, the cathode of a voltage regulator tube ZW1 and the base of a triode Q1, the anode of the voltage regulator tube ZW1 is connected with the grid of a field effect tube T1, the emitter of the triode Q1 is connected with one end of a resistor R9, the other end of the resistor R10 and the other end of the resistor R9 are connected with a power supply +1V, and the collector of the triode Q1 is respectively connected with the control electrode of the thyristor VTL1, the pin 2 of a photoelectric coupler OP;

the in-place error detection circuit comprises a voltage-stabilizing tube ZW2, the negative electrode of a voltage-stabilizing tube ZW2 is connected with a switching valve in-place detection signal, the positive electrode of a voltage-stabilizing tube ZW2 is connected with the non-inverting input end of an operational amplifier AR2, the inverting input end of the operational amplifier AR2 is respectively connected with one end of a resistor R13, one end of a grounding resistor R14 and the emitter of a triode Q3, the other end of the resistor R13 and the collector of the triode Q3 are connected with a switching valve standard in-place signal, the output end of the operational amplifier AR2 is respectively connected with one end of a resistor R15 and the base of a triode Q3, the other end of the resistor R15 is respectively connected with one end of a grounding capacitor C9 and the base of a triode Q4, the emitter of the triode Q4 is connected with a power supply +5V, the collector of the triode Q4 is respectively connected with the upper end of a coil of a relay K.