Electromagnet control circuit

Abstract

The present invention discloses an electromagnet control circuit, comprising: a signal input circuit having an input end connected to an external device and an output end connected to a main control circuit; the main control circuit having an output end connected to the input end of an isolation circuit; the isolation circuit having an output end connected to the input end of a drive circuit; a power supply circuit having an input end connected to mains electricity and an output end connected to the power supply end of the signal input circuit, the power supply end of the main control circuit, the power supply end of the isolation circuit, and the power supply end of the drive circuit; and the drive circuit having an output end connected to the electromagnet. The drive circuit, in combination with the signal input circuit, the main control circuit, the isolation circuit, and the power supply circuit, can output a high-voltage, high-frequency voltage with switchable positive and negative polarities to supply the electromagnet in the intake valve used in a large air compressor, thereby improving the efficiency of the electromagnet control circuit and enabling the large air compressor to be effectively opened or closed.

Description

Technical Field

[0001] The present invention relates to the technical field of electromagnet driving, and in particular to an electromagnet control circuit. Background Art

[0002] When a large air compressor is opened or closed, an intake valve is required to achieve this. However, since the intake valve used in a large air compressor is large, the electromagnet installed inside it is also large. Accordingly, the voltage to drive the electromagnet often needs to be high voltage, high frequency, and the positive and negative poles can be switched. The circuit for controlling the electromagnet in the existing technology often outputs a voltage with only high voltage or high frequency, and cannot achieve the combined function of high voltage, high frequency and positive and negative pole switchability, which reduces the efficiency of the electromagnet control circuit and cannot meet the requirements for effective opening or closing of the air compressor. Summary of the Invention

[0003] Based on this, it is necessary to propose an electromagnet control circuit to address the above problems.

[0004] An electromagnet control circuit, comprising:

[0005] a signal input circuit, the input end of which is connected to an external device, and the output end of which is connected to the main control circuit, for receiving a first-level signal, a second-level signal, a third-level signal, and a fourth-level signal output by the external device, and performing optical isolation on the first-level signal, the second-level signal, the third-level signal, and the fourth-level signal before outputting them to the main control circuit;

[0006] The main control circuit has an output end connected to the input end of the isolation circuit, is used to receive the first level signal, the second level signal, the third level signal and the fourth level signal after optical isolation, and output the first PWM signal, the second PWM signal, the third PWM signal and the fourth PWM signal to the isolation circuit;

[0007] The isolation circuit has an output end connected to an input end of the drive circuit, is configured to receive the first PWM signal, the second PWM signal, the third PWM signal, and the fourth PWM signal, and perform photoelectric isolation on the first PWM signal, the second PWM signal, the third PWM signal, and the fourth PWM signal, amplify the signals, and output the signals to the drive circuit;

[0008] A power supply circuit, the input end of which is connected to the mains power, and the output end is connected to the power supply end of the signal input circuit, the power supply end of the main control circuit, the power supply end of the isolation circuit, and the power supply end of the drive circuit, and is used to convert the mains power into a first voltage and output it to the signal input circuit and the main control circuit; and convert the mains power into a second voltage and a third voltage and output them to the drive circuit;

[0009] The drive circuit, whose output end is connected to the electromagnet, is used to receive the first PWM signal, the second PWM signal, the third PWM signal, the fourth PWM signal, the second voltage and the third voltage after optical isolation, and amplify the second voltage and the third voltage to output positive voltage and negative voltage to the electromagnet.

[0010] In one embodiment, the power supply circuit includes:

[0011] a first voltage conversion circuit, the input end of which is connected to the mains power, and the output end of which is connected to the power supply end of the signal input circuit and the power supply end of the main control circuit, for converting the mains power into a first voltage and outputting the first voltage to the signal input circuit and the main control circuit;

[0012] a second voltage conversion circuit, the input end of which is connected to the mains power, the output end of which is connected to the power supply end of the drive circuit, and converts the mains power into a second voltage and outputs the second voltage to the drive circuit;

[0013] The third voltage conversion circuit has an input end connected to the mains power and an output end connected to the power supply end of the drive circuit, and converts the mains power into a third voltage and outputs the third voltage to the drive circuit.

[0014] In one embodiment, the driving circuit includes:

[0015] a first output circuit, having an input end connected to the output end of the isolation circuit and the output end of the power supply circuit, and an output end connected to the electromagnet, for receiving the first PWM signal, the second PWM signal, the second voltage, and the third voltage after optical isolation, and outputting a positive voltage or a negative voltage to the electromagnet;

[0016] The second output circuit has an input end connected to the output end of the isolation circuit and an output end connected to the electromagnet, and is used to receive the third PWM signal, the fourth PWM signal, the second voltage and the third voltage after optical isolation, and output a negative voltage or a positive voltage to the electromagnet.

[0017] In one embodiment, the signal input circuit includes: an interface, a voltage regulator, a first photoelectric isolation chip and a second photoelectric isolation chip;

[0018] The main control circuit includes: a main control chip;

[0019] The interface is connected to the external device, the first pin of the interface is grounded; the second pin of the interface is connected to the first input terminal of the main control chip and the cathode of the voltage regulator tube, and the anode of the voltage regulator tube is grounded; the third and fourth pins of the interface are respectively connected to the first input terminal and the second input terminal of the first photoelectric isolation chip; the fifth, sixth, seventh and eighth pins of the interface are respectively connected to the first input terminal, the second input terminal, the third input terminal and the fourth input terminal of the second photoelectric isolation chip; the output terminal of the first photoelectric isolation chip is connected to the second input terminal of the main control chip;

[0020] The first output terminal and the second output terminal of the second photoelectric isolation chip are connected to the third input terminal and the fourth input terminal of the main control chip respectively;

[0021] The first output terminal, the second output terminal, the third output terminal and the fourth output terminal of the main control chip are all connected to the input terminal of the isolation circuit.

[0022] In one embodiment, the isolation circuit includes: a third optoelectronic isolation chip;

[0023] The first input terminal, the second input terminal, the third input terminal and the fourth input terminal of the third photoelectric isolation chip are all connected to the output terminal of the main control circuit;

[0024] The first output end, the second output end, the third output end and the fourth output end of the third optoelectronic isolation chip are all connected to the input end of the driving circuit.

[0025] In one embodiment, the first voltage conversion circuit includes: a first transformer, a first rectifier bridge, a first voltage stabilizing chip, a voltage regulator, a first capacitor, a second capacitor, and a third capacitor;

[0026] Two ends of the primary coil of the first transformer are connected to the mains, one end of the secondary coil of the first transformer is connected to the second end of the first rectifier bridge, and the other end of the secondary coil of the first transformer is connected to the third end of the first rectifier bridge;

[0027] The first end of the first rectifier bridge is connected to the external power supply, one end of the first capacitor and the input end of the first voltage regulator chip, and the fourth end of the first rectifier bridge is connected to the other end of the first capacitor and is grounded;

[0028] The output end of the first voltage stabilizing chip is connected to the external power supply, the input end of the voltage regulator and one end of the second capacitor, and the other end of the second capacitor is grounded;

[0029] The third capacitor is connected in parallel with the second capacitor;

[0030] The output end of the voltage regulator is connected to the power supply end of the signal input circuit and the power supply end of the main control circuit.

[0031] In one embodiment, the second voltage conversion circuit includes: a second rectifier bridge, a second diode, a first resistor, a second resistor, a third resistor, a first capacitor, a second capacitor, a third capacitor and a first fuse;

[0032] The first end and the third end of the second rectifier bridge are both connected to the mains, the second end of the second rectifier bridge is connected to one end of the third capacitor, and the fourth end of the second rectifier bridge is connected to the other end of the third capacitor and is grounded;

[0033] The first resistor, the second resistor, the first capacitor and the second capacitor are all connected in parallel with the third capacitor;

[0034] One end of the third resistor is connected to one end of the first capacitor close to the second rectifier bridge, and the other end of the third resistor is connected to one end of the second resistor close to the second rectifier bridge;

[0035] The anode of the second diode is connected to the end of the third resistor close to the second rectifier bridge, and the cathode of the second diode is connected to the end of the first resistor close to the second rectifier bridge.

[0036] In one embodiment, the third voltage conversion circuit includes: a third transformer, a third rectifier bridge, a second voltage stabilizing chip, a fourth transformer, a fourth rectifier bridge, a third voltage stabilizing chip, a fifth transformer, a fifth rectifier bridge, and a fourth voltage stabilizing chip;

[0037] Two ends of the primary coil of the third transformer are connected to the mains power, one end of the secondary coil of the third transformer is connected to the second end of the third rectifier bridge, and the other end of the secondary coil of the third transformer is connected to the third end of the third rectifier bridge; a first end of the third rectifier bridge is connected to the external power supply and the input end of the second voltage stabilizing chip, and a fourth end of the third rectifier bridge is grounded; an output end of the second voltage stabilizing chip is connected to an input end of the drive circuit;

[0038] Two ends of the primary coil of the fourth transformer are connected to the mains power, one end of the secondary coil of the fourth transformer is connected to the second end of the fourth rectifier bridge, and the other end of the secondary coil of the fourth transformer is connected to the third end of the fourth rectifier bridge; a first end of the fourth rectifier bridge is connected to the external power supply and the input end of the third voltage stabilizing chip, and a fourth end of the fourth rectifier bridge is grounded; an output end of the third voltage stabilizing chip is connected to an input end of the drive circuit;

[0039] Both ends of the primary coil of the fifth transformer are connected to the AC power, one end of the secondary coil of the fifth transformer is connected to the second end of the fifth rectifier bridge, and the other end of the secondary coil of the fifth transformer is connected to the third end of the fifth rectifier bridge; the first end of the fifth rectifier bridge is connected to the external power supply and the input end of the fourth voltage regulator chip, and the fourth end of the fifth rectifier bridge is grounded; the output end of the fourth voltage regulator chip is connected to the input end of the drive circuit.

[0040] In one embodiment, the first output circuit includes: a first driver chip, a second driver chip, a first MOS transistor, a second MOS transistor, and a second fuse;

[0041] The control terminal of the first driver chip is connected to the second output terminal of the third optoelectronic isolation chip, and the low-side gate drive output terminal of the first driver chip is connected to the gate of the first MOS transistor; the common terminal of the first driver chip is connected to the source of the first MOS transistor and is grounded, and the power supply terminal of the first driver chip is connected to the output terminal of the power supply circuit;

[0042] The source of the first MOS tube is also connected to one end of the second fuse, and the other end of the second fuse is connected to the electromagnet;

[0043] The control end of the second driver chip is connected to the third output end of the third optoelectronic isolation chip, and the low-side gate drive output end of the second driver chip is connected to the gate of the second MOS tube; the common end of the second driver chip is connected to the source of the second MOS tube and grounded; the power supply end of the second driver chip is connected to the output end of the power supply circuit.

[0044] In one embodiment, the second output circuit includes: a third driver chip, a fourth driver chip, a third MOS transistor, and a fourth MOS transistor;

[0045] The control end of the third driver chip is connected to the first output end of the third optoelectronic isolation chip; the low-side gate drive output end of the third driver chip is connected to the gate of the third MOS tube; the common end of the third driver chip is connected to the source of the third MOS tube and is grounded; the power supply end of the third driver chip is connected to the output end of the power supply circuit;

[0046] The control end of the fourth driver chip is connected to the fourth output end of the third optoelectronic isolation chip; the low-side gate drive output end of the fourth driver chip is connected to the gate of the fourth MOS tube; the common end of the fourth driver chip is connected to the source of the fourth MOS tube and is grounded; the power supply end of the fourth driver chip is connected to the output end of the power supply circuit.

[0047] The implementation of the present invention will have the following beneficial effects:

[0048] The present application receives a first level signal, a second level signal, a third level signal and a fourth level signal output by an external device through a signal input circuit, and performs photoelectric isolation on the first level signal, the second level signal, the third level signal and the fourth level signal before outputting them to a control circuit; a main control circuit receives the first level signal, the second level signal, the third level signal and the fourth level signal after photoelectric isolation, and outputs a first PWM signal, a second PWM signal, a third PWM signal and a fourth PWM signal to the isolation circuit; the isolation circuit receives the first PWM signal, the second PWM signal, the third PWM signal and the fourth PWM signal, and performs photoelectric isolation and amplification on the first PWM signal, the second PWM signal, the third PWM signal and the fourth PWM signal before outputting them to a drive circuit; a power supply circuit converts the mains power into a first voltage and outputs it to the signal input circuit and the main control circuit; and converts the mains power into a second voltage and a third voltage and outputs them to the drive circuit; the drive circuit receives the first PWM signal, the second PWM signal, the third PWM signal, the fourth PWM signal, the second voltage and the third voltage after photoelectric isolation, and amplifies the second voltage and the third voltage and outputs a positive voltage and a negative voltage to the electromagnet. The drive circuit, combined with the signal input circuit, main control circuit, isolation circuit, and power supply circuit, can output a high-voltage, high-frequency voltage with switchable positive and negative polarity to supply the electromagnet in the intake valve used in large air compressors, thereby improving the efficiency of the electromagnet control circuit and enabling the large air compressor to be effectively opened or closed. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0050] in:

[0051] Figure 1 is a structural block diagram of an electromagnet control circuit in one embodiment;

[0052] Figure 2 is a circuit diagram of a signal input circuit in one embodiment;

[0053] Figure 3 is a circuit diagram of a main control circuit in one embodiment;

[0054] Figure 4 is a circuit diagram of an isolation circuit in one embodiment;

[0055] Figure 5 is a circuit diagram of a driving circuit in one embodiment;

[0056] Figure 6 is a circuit diagram of a first voltage conversion circuit in one embodiment;

[0057] Figure 7 is a circuit diagram of a second voltage conversion circuit in one embodiment;

[0058] Figure 8 FIG. 4 is a circuit diagram of a third voltage conversion circuit in one embodiment. DETAILED DESCRIPTION

[0059] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0060] When a large air compressor is opened or closed, an intake valve is required to achieve this. However, since the intake valve used in a large air compressor is relatively large, the electromagnet set up inside it is also relatively large. Accordingly, the voltage to drive the electromagnet often needs to be high voltage, high frequency, and the positive and negative poles can be switched. The circuit that controls the electromagnet in the prior art often outputs a voltage that only has high voltage or high frequency output, and cannot achieve the combined function of high voltage, high frequency and positive and negative pole switchability, which reduces the efficiency of the electromagnet control circuit and cannot meet the requirements for the effective opening or closing of the air compressor. In order to solve the above technical problems, the present application provides an electromagnet control circuit, such as Figure 1As shown, it includes: a signal input circuit 10, a main control circuit 20, an isolation circuit 30, a drive circuit 40 and a power supply circuit 50; wherein the input end of the signal input circuit 10 is connected to an external device, and the output end is connected to the main control circuit 20, for receiving a first level signal, a second level signal, a third level signal and a fourth level signal output by the external device, and performing photoelectric isolation on the first level signal, the second level signal, the third level signal and the fourth level signal, and then outputting the first level signal, the second level signal, the third level signal and the fourth level signal to the main control circuit 20; the output end of the main control circuit 20 is connected to the input end of the isolation circuit 30, for receiving the first level signal, the second level signal, the third level signal and the fourth level signal after photoelectric isolation, and outputting a first PWM signal, a second PWM signal, a third PWM signal and a fourth PWM signal to the isolation circuit 30; the output end of the isolation circuit 30 is connected to the input end of the drive circuit 40, for receiving the first PWM signal, the second PWM signal, the third level signal and the fourth level signal, and then outputting the first PWM signal, the second PWM signal, the third level signal and the fourth level signal to the isolation circuit 30; three PWM signals and the fourth PWM signal, and the first PWM signal, the second PWM signal, the third PWM signal and the fourth PWM signal are optically isolated and amplified before outputting to the drive circuit 40; the input end of the power supply circuit 50 is connected to the mains power, and the output end is connected to the power supply end of the signal input circuit 10, the power supply end of the main control circuit 20, the power supply end of the isolation circuit 30 and the power supply end of the drive circuit 40, for converting the mains power into a first voltage and outputting it to the signal input circuit 10 and the main control circuit 20; and converting the mains power into a second voltage and a third voltage and outputting them to the drive circuit 40; the output end of the drive circuit 40 is connected to the electromagnet, for receiving the first PWM signal, the second PWM signal, the third PWM signal, the fourth PWM signal, the second voltage and the third voltage after optical isolation, and amplifying the second voltage and the third voltage and outputting a positive voltage and a negative voltage to the electromagnet.The present application receives a first level signal, a second level signal, a third level signal, and a fourth level signal output by an external device through a signal input circuit, and performs photoelectric isolation on the first level signal, the second level signal, the third level signal, and the fourth level signal before outputting them to a control circuit; a main control circuit receives the first level signal, the second level signal, the third level signal, and the fourth level signal after photoelectric isolation, and outputs a first PWM signal, a second PWM signal, a third PWM signal, and a fourth PWM signal to an isolation circuit 30; an isolation circuit receives the first PWM signal, the second PWM signal, the third PWM signal, and the fourth PWM signal, and performs photoelectric isolation and amplification on the first PWM signal, the second PWM signal, the third PWM signal, and the fourth PWM signal before outputting them to a drive circuit; a power supply circuit converts the mains power into a first voltage and outputs it to the signal input circuit and the main control circuit; and converts the mains power into a second voltage and a third voltage and outputs them to the drive circuit; the drive circuit receives the first PWM signal, the second PWM signal, the third PWM signal, the fourth PWM signal, the second voltage, and the third voltage after photoelectric isolation, and amplifies the second voltage and the third voltage and outputs a positive voltage and a negative voltage to the electromagnet. The drive circuit, combined with the signal input circuit, main control circuit, isolation circuit, and power supply circuit, can output a high-voltage, high-frequency voltage with switchable positive and negative polarity to supply the electromagnet in the intake valve used in large air compressors, thereby improving the efficiency of the electromagnet control circuit and enabling the large air compressor to be effectively opened or closed.

[0061] In one embodiment, Figure 6-8 As shown, the power supply circuit 50 includes: a first voltage conversion circuit 501, a second voltage conversion circuit 502 and a third voltage conversion circuit 503; wherein, the input end of the first voltage conversion circuit 501 is connected to the mains, and the output end is connected to the power supply end of the signal input circuit 10 and the power supply end of the main control circuit 20, and is used to convert the mains into a first voltage and output it to the signal input circuit 10 and the main control circuit 20; the input end of the second voltage conversion circuit 502 is connected to the mains, and the output end is connected to the power supply end of the drive circuit 40, and converts the mains into a second voltage and outputs it to the drive circuit 40; the input end of the third voltage conversion circuit 503 is connected to the mains, and the output end is connected to the power supply end of the drive circuit 40, and converts the mains into a third voltage and outputs it to the drive circuit 40.

[0062] In one embodiment, Figure 5As shown, the driving circuit 40 includes: a first output circuit 401 and a second output circuit 402, wherein the input end of the first output circuit 401 is connected to the output end of the isolation circuit 30 and the output end of the power supply circuit 50, and the output end is connected to the electromagnet, for receiving the first PWM signal, the second PWM signal, the second voltage and the third voltage after optical isolation, and outputting a positive voltage or a negative voltage to the electromagnet; the input end of the second output circuit 402 is connected to the output end of the isolation circuit 30, and the output end is connected to the electromagnet, for receiving the third PWM signal, the fourth PWM signal, the second voltage and the third voltage after optical isolation, and outputting a negative voltage or a positive voltage to the electromagnet.

[0063] In one embodiment, Figure 2 As shown, the signal input circuit 10 includes: an interface J3, a voltage regulator D16, a first photoelectric isolation chip U1 and a second photoelectric isolation chip D2; Figure 3As shown, the main control circuit 20 includes: a main control chip U9; wherein the main control chip U9 uses an STM32F10RCT6 advanced single-chip microcomputer as the main controller, and the external device (i.e., the PLC) outputs a 0-10V analog quantity and adds it to the first input terminal PA1 of the main control chip U9. To ensure the safety of the pins of the main control chip U9, a 3.3V voltage regulator D16 is connected in parallel to the first input terminal PA1 of the main control chip U9 to ensure that the voltage on the first input terminal PA1 of the main control chip U9 does not exceed 3.3V. The PLC transmits the first level signal, the second level signal, the third level signal, and the fourth level signal to the third input terminal PA2 and the fourth input terminal PA3 of the main control chip U9 through a second optoelectronic isolation chip D2 of model TLP521-2, which is used to instruct the single-chip microcomputer to output the positive and negative voltages and the power on and off to the electromagnet accordingly. The interface J3 is connected to the external device, and the first pin 1 of the interface J3 is grounded; the second pin 2 of the interface J3 is connected to the first input terminal PA1 of the main control chip U9 and the cathode of the voltage regulator D16, and the anode of the voltage regulator D16 is grounded; the third pin 3 and the fourth pin 4 of the interface J3 are respectively connected to the first input terminal 3 and the second input terminal 4 of the first photoelectric isolation chip U1; the fifth pin 5, the sixth pin 6, the seventh pin 7 and the eighth pin 8 of the interface J3 are respectively connected to the first input terminal A1, The second input terminal K1, the third input terminal A2 and the fourth input terminal K2 are connected; the output terminal 1 of the first optoelectronic isolation chip U1 is connected to the second input terminal PA4 of the main control chip U9; the first output terminal C1 and the second output terminal C2 of the second optoelectronic isolation chip D2 are respectively connected to the third input terminal PA2 and the fourth input terminal PA3 of the main control chip U9; the first output terminal PA8, the second output terminal PC8, the third output terminal PC6 and the fourth output terminal PB14 of the main control chip U9 are all connected to the input terminal of the isolation circuit 30.

[0064] In one embodiment, Figure 4 As shown, the isolation circuit 30 includes: a third optoelectronic isolation chip U2; wherein the first input terminal 2, the second input terminal 4, the third input terminal 6 and the fourth input terminal 8 of the third optoelectronic isolation chip U2 are all connected to the output terminal of the main control circuit 20; the first output terminal 16, the second output terminal 14, the third output terminal 12 and the fourth output terminal 10 of the third optoelectronic isolation chip U2 are all connected to the input terminal of the drive circuit 40.

[0065] In one embodiment, Figure 6As shown, the first voltage conversion circuit 501 includes: a first transformer T4, a first rectifier bridge D1, a first voltage regulator chip U4, a voltage regulator J6, a first capacitor C1, a second capacitor C2 and a third capacitor C3; wherein, the two ends of the primary coil of the first transformer T4 are connected to the mains, one end of the secondary coil of the first transformer T4 is connected to the second end 2 of the first rectifier bridge D1, and the other end of the secondary coil of the first transformer T4 is connected to the third end 3 of the first rectifier bridge D1; the first end 1 of the first rectifier bridge D1 is connected to the external power supply, the first One end of the capacitor C1 is connected to the input end Vin of the first voltage regulator chip U4, and the fourth end 4 of the first rectifier bridge D1 is connected to the other end of the first capacitor C1 and grounded; the output end Vout of the first voltage regulator chip U4 is connected to the external power supply, the input end 3 of the voltage regulator J6 and one end of the second capacitor C2, and the other end of the second capacitor C2 is grounded; the third capacitor C3 is connected in parallel with the second capacitor C2; the output end 2 of the voltage regulator J6 is connected to the power supply end of the signal input circuit 10 and the power supply end of the main control circuit 20.

[0066] In one embodiment, Figure 7 As shown, the second voltage conversion circuit 502 includes: a second rectifier bridge D17, a second diode D3, a first resistor R6, a second resistor R31, a third resistor R37, a first capacitor C10, a second capacitor C12, a third capacitor C15 and a first fuse F1; wherein the first end 1 and the third end 3 of the second rectifier bridge D17 are both connected to the mains, the second end 2 of the second rectifier bridge D17 is connected to one end of the third capacitor C15, and the fourth end 4 of the second rectifier bridge D17 is connected to the other end of the third capacitor C15 and is grounded; the first resistor R6, the second resistor R31, the third resistor R37, the first capacitor C10, the second capacitor C12, the third capacitor C15 and the first fuse F1; wherein the first end 1 and the third end 3 of the second rectifier bridge D17 are both connected to the mains, the second end 2 of the second rectifier bridge D17 is connected to one end of the third capacitor C15, and the fourth end 4 of the second rectifier bridge D17 is connected to the other end of the third capacitor C15 and is grounded; The resistor R31, the first capacitor C10 and the second capacitor C12 are all connected in parallel with the third capacitor C15; one end of the third resistor R37 is connected to an end of the first capacitor C10 close to the second rectifier bridge D17, and the other end of the third resistor R37 is connected to an end of the second resistor R31 close to the second rectifier bridge D17; the anode of the second diode D3 is connected to an end of the third resistor R37 close to the second rectifier bridge D17, and the cathode of the second diode D3 is connected to an end of the first resistor R6 close to the second rectifier bridge D17.

[0067] In one embodiment, Figure 8As shown, the third voltage conversion circuit 503 includes: a third transformer T3, a third rectifier bridge D13, a second voltage stabilizing chip U6, a fourth transformer T2, a fourth rectifier bridge D12, a third voltage stabilizing chip U7, a fifth transformer T1, a fifth rectifier bridge D14 and a fourth voltage stabilizing chip U5; wherein, the two ends of the primary coil of the third transformer T3 are connected to the mains, one end of the secondary coil of the third transformer T3 is connected to the second end 2 of the third rectifier bridge D13, and the other end of the secondary coil of the third transformer T3 is connected to the third end 3 of the third rectifier bridge D13; the first end 1 of the third rectifier bridge D13 is connected to the external power supply and the input end Vin of the second voltage stabilizing chip U6, and the fourth end 4 of the third rectifier bridge D13 is grounded; the output end Vout of the second voltage stabilizing chip U6 is connected to the input end of the drive circuit 40; the two ends of the primary coil of the fourth transformer T2 are connected to the mains, and one end of the secondary coil of the fourth transformer T2 is connected to the fourth rectifier bridge D13. The second end 2 of the rectifier bridge D12 is connected, and the other end of the secondary coil of the fourth transformer T2 is connected to the third end 3 of the fourth rectifier bridge D12; the first end 1 of the fourth rectifier bridge D12 is connected to the external power supply and the input end Vin of the third voltage regulator chip U7, and the fourth end 4 of the fourth rectifier bridge D12 is grounded; the output end Vout of the third voltage regulator chip U7 is connected to the input end of the drive circuit 40; the two ends of the primary coil of the fifth transformer T1 are connected to the mains, one end of the secondary coil of the fifth transformer T1 is connected to the second end 2 of the fifth rectifier bridge D14, and the other end of the secondary coil of the fifth transformer T1 is connected to the third end 3 of the fifth rectifier bridge D14; the first end 1 of the fifth rectifier bridge D14 is connected to the external power supply and the input end Vin of the fourth voltage regulator chip U5, and the fourth end 4 of the fifth rectifier bridge D14 is grounded; the output end Vout of the fourth voltage regulator chip U5 is connected to the input end of the drive circuit 40.

[0068] In one embodiment, Figure 5As shown, the first output circuit 401 includes: a first driver chip D8, a second driver chip D9, a first MOS transistor Q1, a second MOS transistor Q3 and a second fuse F2; the second output circuit 402 includes: a third driver chip D10, a fourth driver chip D11, a third MOS transistor Q2 and a fourth MOS transistor Q4; wherein, the control terminal LIN of the first driver chip D8 is connected to the second output terminal 14 of the third optoelectronic isolation chip U2, and the low-side gate drive output terminal LO of the first driver chip D8 is connected to the gate of the first MOS transistor Q1; the common terminal COM of the first driver chip D8 is connected to the source of the first MOS transistor Q1 and is grounded, and the fourth driver chip D11 is connected to the gate of the first MOS transistor Q1. A power supply terminal VCC of a driver chip D8 is connected to the output terminal of the power supply circuit 50; the source of the first MOS transistor Q1 is also connected to one end of the second fuse F2, and the other end of the second fuse F2 is connected to the electromagnet; the control terminal LIN of the second driver chip D9 is connected to the third output terminal 12 of the third optoelectronic isolation chip U2, and the low-side gate drive output terminal LO of the second driver chip D9 is connected to the gate of the second MOS transistor Q3; the common terminal COM of the second driver chip D9 is connected to the source of the second MOS transistor Q3 and is grounded; the power supply terminal VCC of the second driver chip D9 is connected to the output terminal of the power supply circuit 50. The control terminal LIN of the third driver chip D10 is connected to the first output terminal 16 of the third optoelectronic isolation chip U2; the low-side gate drive output terminal LO of the third driver chip D10 is connected to the gate of the third MOS transistor Q2; the common terminal COM of the third driver chip D10 is connected to the source of the third MOS transistor Q2 and is grounded; the power supply terminal VCC of the third driver chip D10 is connected to the output terminal of the power supply circuit 50; the control terminal LIN of the fourth driver chip D11 is connected to the fourth output terminal 10 of the third optoelectronic isolation chip U2; the low-side gate drive output terminal LO of the fourth driver chip D11 is connected to the gate of the fourth MOS transistor Q4; the common terminal COM of the fourth driver chip D11 is connected to the source of the fourth MOS transistor Q4 and is grounded; the power supply terminal VCC of the fourth driver chip D11 is connected to the output terminal of the power supply circuit 50.

[0069] The working principle of this application is as follows:

[0070] The external device can be a PLC, which outputs a first level signal, a second level signal, a third level signal and a fourth level signal to the first optoelectronic isolation chip U1 and the second optoelectronic isolation chip D2 to the main control chip U9 through the PLC. The main control chip U9 receives the first level signal, the second level signal, the third level signal and the fourth level signal after optoelectronic isolation, and the main control chip U9 outputs a first PWM signal, a second PWM signal, a third PWM signal and a fourth PWM signal to the third optoelectronic isolation chip U2; the third optoelectronic isolation chip U2 optoelectronically isolates and amplifies the first PWM signal, the second PWM signal, the third PWM signal and the fourth PWM signal, and then outputs them to the first driver chip D8, the second driver chip D9, the third driver chip D10 and the fourth driver chip D11 respectively; the first driver chip D8, the second driver chip D9, the third driver chip D10 and the fourth driver chip D11 respectively drive the first MOS transistor Q1, the second MOS transistor Q3, the third MOS transistor Q2 and the fourth MOS transistor Q4 to be turned on and off. The bridge circuit composed of the first MOS transistor Q1, the second MOS transistor Q3, the third MOS transistor Q2 and the fourth MOS transistor Q4 can provide forward voltage and reverse voltage to the electromagnet; the second fuse F2 ensures that the output voltage of the drive circuit 40 is cut off in time when an abnormality occurs in the circuit.

[0071] When the second output terminal PC8 and the fourth output terminal PB14 of the main control chip U9 output a low level (0) to the second input terminal 4 and the fourth input terminal 8 of the third optoelectronic isolation chip U2, respectively, the third pin of the third optoelectronic isolation chip U2 is connected to the light-emitting diode inside the third optoelectronic isolation chip U2, and then a low level is received through the second input terminal 4 to form a loop, so that the light-emitting diode inside the third optoelectronic isolation chip U2 emits light. Since the light-emitting diode inside the third optoelectronic isolation chip U2 emits light, the phototransistor at the corresponding position inside the third optoelectronic isolation chip U2 will be turned on, so that the 14th pin O2 and gnd2 of the third optoelectronic isolation chip U2 form a loop and turn on, which is equivalent to connecting the 14th pin O2 and gnd2 together. In addition, the 3rd pin of the first driver chip D8 is a low level trigger, so the 5th pin of the first driver chip D8 will output a PWM signal, which is a high level relative to gnd2. Therefore, the first MOS tube Q1 will be turned on, and the voltage will pass from the 300V DC end through the first MOS tube Q1 to OUT0 and then to the OUT2 end through the second fuse F2, which is a positive voltage output of 300V. Similarly, the tenth pin O4 of the third optoelectronic isolation chip U2 and GND1 are connected, and the fifth pin of the fourth driver chip D11 also outputs a high level. The fourth MOS tube Q4 is turned on, and OUT1 is connected to the negative end of the 300V power supply through the fourth MOS tube Q4, so that OUT2 outputs positive 300V to the negative pole of OUT1. If an electromagnet is connected to OUT2 and OUT1, a positive voltage can be passed.

[0072] If OUT1 outputs a positive voltage of 300V and OUT2 outputs a negative voltage of 300V, the third MOS transistor Q2 and the second MOS transistor Q3 need to be turned on, and the 12th pin O1 and the 16th pin O3 of the third optoelectronic isolation chip U2 need to be turned on. Therefore, the first input terminal 2 and the third input terminal 6 of the third optoelectronic isolation chip U2 need to be turned on (the specific principle is the same as above and will not be repeated here).

[0073] The above disclosure is merely a preferred embodiment of the present invention and certainly cannot be used to limit the scope of the present invention. Therefore, equivalent changes made according to the claims of the present invention are still within the scope of the present invention.

Claims

1. An electromagnet control circuit, characterized in that: include: a signal input circuit, the input end of which is connected to an external device, and the output end of which is connected to the main control circuit, for receiving a first-level signal, a second-level signal, a third-level signal, and a fourth-level signal output by the external device, and performing optical isolation on the first-level signal, the second-level signal, the third-level signal, and the fourth-level signal before outputting them to the main control circuit; The main control circuit has an output end connected to the input end of the isolation circuit, is used to receive the first level signal, the second level signal, the third level signal and the fourth level signal after optical isolation, and output the first PWM signal, the second PWM signal, the third PWM signal and the fourth PWM signal to the isolation circuit; The isolation circuit has an output end connected to an input end of the drive circuit, is configured to receive the first PWM signal, the second PWM signal, the third PWM signal, and the fourth PWM signal, and perform photoelectric isolation on the first PWM signal, the second PWM signal, the third PWM signal, and the fourth PWM signal, amplify the signals, and output the signals to the drive circuit; A power supply circuit, the input end of which is connected to the mains power, and the output end of which is connected to the power supply end of the signal input circuit, the power supply end of the main control circuit, the power supply end of the isolation circuit, and the power supply end of the drive circuit, and is used to convert the mains power into a first voltage and output it to the signal input circuit and the main control circuit; and converting the mains power into a second voltage and a third voltage and outputting the converted voltage to the drive circuit; The drive circuit has an output end connected to the electromagnet, and is configured to receive the first PWM signal, the second PWM signal, the third PWM signal, the fourth PWM signal, the second voltage, and the third voltage after being photoelectrically isolated, and amplify the second voltage and the third voltage to output a positive voltage and a negative voltage to the electromagnet; Wherein, the signal input circuit includes: an interface, a voltage regulator tube, a first photoelectric isolation chip and a second photoelectric isolation chip; The main control circuit includes: a main control chip; The interface is connected to the external device, and the first pin of the interface is grounded; the second pin of the interface is connected to the first input terminal of the main control chip and the cathode of the voltage regulator tube, and the anode of the voltage regulator tube is grounded; the third and fourth pins of the interface are respectively connected to the first input terminal and the second input terminal of the first photoelectric isolation chip; the fifth, sixth, seventh and eighth pins of the interface are respectively connected to the first input terminal, the second input terminal, the third input terminal and the fourth input terminal of the second photoelectric isolation chip; the output terminal of the first photoelectric isolation chip is connected to the second input terminal of the main control chip; The first output terminal and the second output terminal of the second photoelectric isolation chip are connected to the third input terminal and the fourth input terminal of the main control chip respectively; The first output terminal, the second output terminal, the third output terminal and the fourth output terminal of the main control chip are all connected to the input terminal of the isolation circuit.

2. The electromagnet control circuit according to claim 1, characterized in that: The power supply circuit includes: a first voltage conversion circuit, the input end of which is connected to the mains power, and the output end of which is connected to the power supply end of the signal input circuit and the power supply end of the main control circuit, for converting the mains power into a first voltage and outputting the first voltage to the signal input circuit and the main control circuit; a second voltage conversion circuit, the input end of which is connected to the mains power, the output end of which is connected to the power supply end of the drive circuit, and converts the mains power into a second voltage and outputs the second voltage to the drive circuit; The third voltage conversion circuit has an input end connected to the mains power and an output end connected to the power supply end of the drive circuit, and converts the mains power into a third voltage and outputs the third voltage to the drive circuit.

3. The electromagnet control circuit according to claim 1, characterized in that: The driving circuit includes: a first output circuit, having an input end connected to the output end of the isolation circuit and the output end of the power supply circuit, and an output end connected to the electromagnet, for receiving the first PWM signal, the second PWM signal, the second voltage, and the third voltage after optical isolation, and outputting a positive voltage or a negative voltage to the electromagnet; The second output circuit has an input end connected to the output end of the isolation circuit and an output end connected to the electromagnet, and is used to receive the third PWM signal, the fourth PWM signal, the second voltage and the third voltage after optical isolation, and output a negative voltage or a positive voltage to the electromagnet.

4. The electromagnet control circuit according to claim 3, characterized in that: The isolation circuit includes: a third photoelectric isolation chip; The first input terminal, the second input terminal, the third input terminal and the fourth input terminal of the third photoelectric isolation chip are all connected to the output terminal of the main control circuit; The first output end, the second output end, the third output end and the fourth output end of the third optoelectronic isolation chip are all connected to the input end of the driving circuit.

5. The electromagnet control circuit according to claim 2, characterized in that: The first voltage conversion circuit includes: a first transformer, a first rectifier bridge, a first voltage stabilizing chip, a voltage regulator, a first capacitor, a second capacitor and a third capacitor; Two ends of the primary coil of the first transformer are connected to the mains, one end of the secondary coil of the first transformer is connected to the second end of the first rectifier bridge, and the other end of the secondary coil of the first transformer is connected to the third end of the first rectifier bridge; The first end of the first rectifier bridge is connected to an external power supply, one end of the first capacitor, and an input end of the first voltage regulator chip, and the fourth end of the first rectifier bridge is connected to the other end of the first capacitor and is grounded; The output end of the first voltage stabilizing chip is connected to the external power supply, the input end of the voltage regulator and one end of the second capacitor, and the other end of the second capacitor is grounded; The third capacitor is connected in parallel with the second capacitor; The output end of the voltage regulator is connected to the power supply end of the signal input circuit and the power supply end of the main control circuit.

6. The electromagnet control circuit according to claim 2, characterized in that: The second voltage conversion circuit includes: a second rectifier bridge, a second diode, a first resistor, a second resistor, a third resistor, a first capacitor, a second capacitor, a third capacitor and a first fuse; The first end and the third end of the second rectifier bridge are both connected to the mains, the second end of the second rectifier bridge is connected to one end of the third capacitor, and the fourth end of the second rectifier bridge is connected to the other end of the third capacitor and is grounded; The first resistor, the second resistor, the first capacitor and the second capacitor are all connected in parallel with the third capacitor; One end of the third resistor is connected to one end of the first capacitor close to the second rectifier bridge, and the other end of the third resistor is connected to one end of the second resistor close to the second rectifier bridge; An anode of the second diode is connected to an end of the second resistor close to the second rectifier bridge, and a cathode of the second diode is connected to an end of the first resistor close to the second rectifier bridge.

7. The electromagnet control circuit according to claim 2, characterized in that: The third voltage conversion circuit includes: a third transformer, a third rectifier bridge, a second voltage stabilizing chip, a fourth transformer, a fourth rectifier bridge, a third voltage stabilizing chip, a fifth transformer, a fifth rectifier bridge and a fourth voltage stabilizing chip; Two ends of the primary coil of the third transformer are connected to the mains power, one end of the secondary coil of the third transformer is connected to the second end of the third rectifier bridge, and the other end of the secondary coil of the third transformer is connected to the third end of the third rectifier bridge; a first end of the third rectifier bridge is connected to an external power supply and an input end of the second voltage stabilizing chip, and a fourth end of the third rectifier bridge is grounded; an output end of the second voltage stabilizing chip is connected to an input end of the drive circuit; Two ends of the primary coil of the fourth transformer are connected to the mains power, one end of the secondary coil of the fourth transformer is connected to the second end of the fourth rectifier bridge, and the other end of the secondary coil of the fourth transformer is connected to the third end of the fourth rectifier bridge; a first end of the fourth rectifier bridge is connected to the external power supply and the input end of the third voltage stabilizing chip, and a fourth end of the fourth rectifier bridge is grounded; an output end of the third voltage stabilizing chip is connected to an input end of the drive circuit; Both ends of the primary coil of the fifth transformer are connected to the AC power, one end of the secondary coil of the fifth transformer is connected to the second end of the fifth rectifier bridge, and the other end of the secondary coil of the fifth transformer is connected to the third end of the fifth rectifier bridge; the first end of the fifth rectifier bridge is connected to the external power supply and the input end of the fourth voltage regulator chip, and the fourth end of the fifth rectifier bridge is grounded; the output end of the fourth voltage regulator chip is connected to the input end of the drive circuit.

8. The electromagnet control circuit according to claim 4, characterized in that: The first output circuit includes: a first driver chip, a second driver chip, a first MOS transistor, a second MOS transistor and a second fuse; The control terminal of the first driver chip is connected to the second output terminal of the third optoelectronic isolation chip, and the low-side gate drive output terminal of the first driver chip is connected to the gate of the first MOS transistor; the common terminal of the first driver chip is connected to the source of the first MOS transistor and is grounded, and the power supply terminal of the first driver chip is connected to the output terminal of the power supply circuit; The source of the first MOS tube is also connected to one end of the second fuse, and the other end of the second fuse is connected to the electromagnet; The control end of the second driver chip is connected to the third output end of the third optoelectronic isolation chip, and the low-side gate drive output end of the second driver chip is connected to the gate of the second MOS tube; the common end of the second driver chip is connected to the source of the second MOS tube and grounded; the power supply end of the second driver chip is connected to the output end of the power supply circuit.

9. The electromagnet control circuit according to claim 8, characterized in that: The second output circuit includes: a third driver chip, a fourth driver chip, a third MOS transistor and a fourth MOS transistor; The control end of the third driver chip is connected to the first output end of the third optoelectronic isolation chip; the low-side gate drive output end of the third driver chip is connected to the gate of the third MOS tube; the common end of the third driver chip is connected to the source of the third MOS tube and is grounded; the power supply end of the third driver chip is connected to the output end of the power supply circuit; The control end of the fourth driver chip is connected to the fourth output end of the third optoelectronic isolation chip; the low-side gate drive output end of the fourth driver chip is connected to the gate of the fourth MOS tube; the common end of the fourth driver chip is connected to the source of the fourth MOS tube and is grounded; the power supply end of the fourth driver chip is connected to the output end of the power supply circuit.

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