CN110048583A - A kind of SCR double drive isolation circuit module - Google Patents

Abstract

The invention discloses an SCR dual drive isolation circuit module, which includes an SCR drive control circuit, a power conversion circuit and an SCR dual drive isolation circuit. The SCR drive control circuit controls the on-off of a MOS tube through a drive signal, and generates a logic signal to control the flyback circuit The work of the control chip, and then control the SCR dual drive isolation signal at the output end; the power conversion circuit isolates and rectifies the primary side 12V voltage through the transformer to generate two sets of voltages of equal size; the SCR dual drive isolation circuit isolates the two sets of voltages after rectification. Equal voltages are respectively applied between the G and K poles of the controlled SCR after the step-down clamping process to drive the conduction of the SCR. The invention adopts independent modular design, simple circuit and low cost. The drive board of the SCR dual-drive isolation circuit module has the advantages of small overall occupied space, perfect SCR protection and quick action, and improves stability and safety.

Description

A SCR dual drive isolation circuit module

technical field

The invention belongs to the technical field of integrated electronic circuits, in particular to an SCR dual-drive isolation circuit module.

Background technique

Thyristor (Thyristor) is the abbreviation of thyristor, also known as silicon controlled rectifier. SCR is a bipolar device with high blocking voltage, low on-state voltage, and large current capacity. It is used in large and medium power equipment. Therefore, thyristor components are widely used in circuits of various electronic equipment and electronic products. It is mostly used for controllable rectification, inverter, frequency conversion, voltage regulation, non-contact switch and other purposes.

SCR is a current-mode control device. Its interior is a PNP four-layer semiconductor structure. SCR is equivalent to a solid-state switch. It is easily triggered by a narrow pulse applied to the gate, and it can still be turned on after the pulse disappears. Once turned on, it needs to be turned off at a certain time point, and it needs to be turned off by the action of an external voltage or an external circuit. Therefore, the basic requirement of the SCR drive circuit is to ensure that the SCR turns from blocking to conducting at the required moment. The width of the trigger pulse connected to the input terminal can ensure the reliable conduction of the SCR with sufficient amplitude. In addition, the SCR drive circuit should also have good anti-interference performance, stability and electrical isolation of the main circuit.

Existing SCR drive circuits include optical fiber isolated drive circuits and integrated drive circuits. Optical fiber isolated drive circuits mainly use optical fibers with faster transmission speed as the isolation of strong and weak electricity, although their reliability is high and the energy transfer is small. , but the cost is high, so it is rarely used in general industrial occasions; the integrated drive circuit has the advantages of small size, low power consumption and convenient debugging, but the cost is high, the versatility is poor, the anti-interference ability is poor, and the reliability is also poor.

SUMMARY OF THE INVENTION

The present invention provides an SCR dual-drive isolation circuit module to solve the technical difficulties such as slow turn-off speed of the SCR drive circuit, non-isolated drive, difficult maintenance, etc., and to improve the safety and stability of the circuit.

In order to solve the above-mentioned technical problems, the present invention provides the following technical solutions:

The present invention is an SCR dual drive isolation circuit module, which includes an SCR drive control circuit, a power conversion circuit and an SCR dual drive isolation circuit. The SCR drive control circuit controls the on-off of a MOS tube through a drive signal, and generates a logic signal to control the control of the flyback circuit. The work of the chip, and then control the SCR dual drive isolation signal at the output end; the power conversion circuit isolates and rectifies the primary side 12V voltage through the transformer to generate two sets of equal voltages; the SCR dual drive isolation circuit isolates the two sets of equal size voltages after rectification. The voltage is applied between the G and K poles of the controlled SCR after being processed by the step-down clamp, and is used to drive the conduction of the SCR.

As a preferred technical solution of the present invention, the SCR dual-drive isolation circuit module includes a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, a first MOS tube Q1, second MOS tube Q2, third MOS tube Q3, fourth transistor Q4, fifth transistor Q5, first diode D1, second diode D2, third diode D3, The fourth diode D4, the fifth diode D5, the sixth diode D6, the seventh diode D7, the eighth diode D8, the first capacitor C1, the second capacitor C2, the third capacitor C3, The fourth capacitor C4, the control chip U1 and the transformer T1, the control chip U1 is an LM5020 chip;

The SCR drive control circuit includes: pin 1 of the second MOS transistor Q2 is connected to the driving signal DRV of the SCR, pin 2 of the second MOS transistor Q2 is connected to one end of the first resistor R1, and pin 1 of the third MOS transistor Q3 is connected. The other end of the resistor R1 is connected to pins 1 and 4 of the control chip U1 and +12V, the pin 2 of the third MOS transistor Q3 is connected to the pin 3 of the control chip U1, the pin 3 of the second MOS transistor Q2, the third MOS transistor Pin 3 of Q3 is grounded;

The power conversion circuit and the SCR dual drive isolation circuit include: one end of the first capacitor C1 is connected to +12V, pins 1 and 4 of the control chip U1, one end of the first resistor R1, and pin 1 of the transformer T1. The other end is grounded; pin 10 of the control chip U1 is connected to one end of the second capacitor C2, and the other end of the second capacitor C2 is grounded; the pin 9 of the control chip U1 is connected to one end of the second resistor R2, and the other end of the second resistor R2 Grounding; pins 2, 6 and 8 of the control chip U1 are grounded; pin 5 of the control chip U1 is connected to pin 1 of the first MOS transistor Q1, and pin 2 of the first MOS transistor Q1 is connected to pin 2 of the transformer T1. Pin 3 of a MOS transistor Q1 is grounded; pin 6 of the transformer T1 is connected to the anode of the first diode D1, the cathode of the first diode D1 is connected to the anode of the second diode D2, the third resistor R3, the third One end of the capacitor C3 is connected, and the other end of the third capacitor C3 is connected to the other end of the third resistor R3, the cathode of the fourth diode D4, and the emitter of the fifth transistor Q5; the cathode of the second diode D2 Connected to the anode of the third diode D3, the cathode of the third diode D3 is connected to the anode of the fourth diode D4, the base of the fifth transistor Q5, and one end of the fourth resistor R4, the fourth resistor The other end of R4 is connected to pin 5 and SCR-1K of the transformer T1; the collector of the fifth transistor Q5 is connected to SCR-1G; the pin 4 of the transformer T1 is connected to the anode of the fifth diode D5, the fifth The cathode of the diode D5 is connected to the anode of the sixth diode D6, one end of the fifth resistor R5, and one end of the fourth capacitor C4, and the other end of the fourth capacitor C4 is connected to the other end of the fifth resistor R5, the eighth second The cathode of the diode D8 is connected to the emitter of the fourth transistor Q4; the cathode of the sixth diode D6 is connected to the anode of the seventh diode D7, and the cathode of the seventh diode D7 is connected to the eighth diode The anode of D8, the base of the fourth transistor Q4, and one end of the sixth resistor R6 are connected, and the other end of the sixth resistor R6 is connected to the 3-pin of the transformer T1 and the SCR-2K terminal; the collector of the fourth transistor Q4 The electrodes are connected to the SCR-2G.

Specifically, the first MOS transistor Q1, the second MOS transistor Q2, and the third MOS transistor Q3 are N-type MOS transistors, and the 1 pin of the first MOS transistor Q1, the second MOS transistor Q2, and the third MOS transistor Q3 is the gate, Pins 2 of the first MOS transistor Q1, the second MOS transistor Q2, and the third MOS transistor Q3 are drain electrodes, and the pins 3 of the first MOS transistor Q1, the second MOS transistor Q2, and the third MOS transistor Q3 are sources.

Specifically, the fourth transistor Q4 and the fifth transistor Q5 are NPN transistors.

Specifically, the driving signal DRV of the SCR is synchronized with the dual output signal.

The beneficial effects of the present invention are as follows: the present invention adopts an independent modular design, the circuit is simple, and the cost is reduced; the driving board of the SCR dual-drive isolation circuit module has the advantages of small overall occupied space, perfect SCR protection and rapid action, and improves the stability and security.

Description of drawings

1 is a circuit schematic diagram of a SCR dual-drive isolation circuit module of the present invention;

FIG. 2 is an internal structure diagram of an LM5020 chip in an SCR dual-drive isolation circuit module of the present invention.

Detailed ways

The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention, but not to limit the present invention.

In the description of the present invention, it should be noted that, unless otherwise expressly specified and limited, the term "connected" refers to electrical connection, which should be understood in a broad sense. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood in specific situations.

In order to achieve the purpose of the present invention, as shown in FIG. 1 to FIG. 2 , in one of the embodiments of the present invention, an SCR dual-drive isolation circuit module is provided, including an SCR drive control circuit, a power conversion circuit and an SCR dual-drive isolation circuit Circuit, the SCR drive control circuit controls the on-off of the MOS tube through the drive signal, generates a logic signal to control the work of the control chip of the flyback circuit, and then controls the SCR dual drive isolation signal at the output end; the power conversion circuit isolates the primary 12V voltage through a transformer After rectification, two sets of voltages of equal size are generated; SCR dual drive isolation adds the two sets of voltages of equal size after rectification to the G and K poles of the controlled SCR after buck clamping, respectively, to drive the SCR. conduction.

Specifically, the SCR dual-drive isolation circuit module includes a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, a first MOS transistor Q1, and a second MOS transistor Q2, the third MOS transistor Q3, the fourth transistor Q4, the fifth transistor Q5, the first diode D1, the second diode D2, the third diode D3, the fourth diode D4, Fifth diode D5, sixth diode D6, seventh diode D7, eighth diode D8, first capacitor C1, second capacitor C2, third capacitor C3, fourth capacitor C4, control chip U1 and transformer T1, the control chip U1 is LM5020 chip;

The SCR drive control circuit includes: pin 1 of the second MOS transistor Q2 is connected to the driving signal DRV of the SCR, pin 2 of the second MOS transistor Q2 is connected to one end of the first resistor R1, and pin 1 of the third MOS transistor Q3 is connected. The other end of the resistor R1 is connected to pins 1 and 4 of the control chip U1 and +12V, the pin 2 of the third MOS transistor Q3 is connected to the pin 3 of the control chip U1, the pin 3 of the second MOS transistor Q2, the third MOS transistor Pin 3 of Q3 is grounded;

The power conversion circuit and the SCR dual drive isolation circuit include: one end of the first capacitor C1 is connected to +12V, pins 1 and 4 of the control chip U1, one end of the first resistor R1, and pin 1 of the transformer T1. The other end is grounded; pin 10 of the control chip U1 is connected to one end of the second capacitor C2, and the other end of the second capacitor C2 is grounded; the pin 9 of the control chip U1 is connected to one end of the second resistor R2, and the other end of the second resistor R2 Grounding; pins 2, 6 and 8 of the control chip U1 are grounded; pin 5 of the control chip U1 is connected to pin 1 of the first MOS transistor Q1, and pin 2 of the first MOS transistor Q1 is connected to pin 2 of the transformer T1. Pin 3 of a MOS transistor Q1 is grounded; pin 6 of the transformer T1 is connected to the anode of the first diode D1, the cathode of the first diode D1 is connected to the anode of the second diode D2, the third resistor R3, the third One end of the capacitor C3 is connected, and the other end of the third capacitor C3 is connected to the other end of the third resistor R3, the cathode of the fourth diode D4, and the emitter of the fifth transistor Q5; the cathode of the second diode D2 Connected to the anode of the third diode D3, the cathode of the third diode D3 is connected to the anode of the fourth diode D4, the base of the fifth transistor Q5, and one end of the fourth resistor R4, the fourth resistor The other end of R4 is connected to pin 5 and SCR-1K of the transformer T1; the collector of the fifth transistor Q5 is connected to SCR-1G; the pin 4 of the transformer T1 is connected to the anode of the fifth diode D5, the fifth The cathode of the diode D5 is connected to the anode of the sixth diode D6, one end of the fifth resistor R5, and one end of the fourth capacitor C4, and the other end of the fourth capacitor C4 is connected to the other end of the fifth resistor R5, the eighth second The cathode of the diode D8 is connected to the emitter of the fourth transistor Q4; the cathode of the sixth diode D6 is connected to the anode of the seventh diode D7, and the cathode of the seventh diode D7 is connected to the eighth diode The anode of D8, the base of the fourth transistor Q4, and one end of the sixth resistor R6 are connected, and the other end of the sixth resistor R6 is connected to the 3-pin of the transformer T1 and the SCR-2K terminal; the collector of the fourth transistor Q4 The electrodes are connected to the SCR-2G.

Specifically, the first MOS transistor Q1, the second MOS transistor Q2, and the third MOS transistor Q3 are N-type MOS transistors, and the 1 pin of the first MOS transistor Q1, the second MOS transistor Q2, and the third MOS transistor Q3 is the gate, Pins 2 of the first MOS transistor Q1, the second MOS transistor Q2, and the third MOS transistor Q3 are drain electrodes, and the pins 3 of the first MOS transistor Q1, the second MOS transistor Q2, and the third MOS transistor Q3 are sources.

Specifically, the fourth transistor Q4 and the fifth transistor Q5 are NPN transistors.

Specifically, the driving signal DRV of the SCR is synchronized with the dual output signal.

The working principle of the SCR drive control circuit is as follows: SCR gives a high-level drive signal, the second MOS transistor Q2 is turned on, the third MOS transistor Q3 is turned off, and the 3-pin of the control chip U1 is at a high level, and the control chip U1 works normally. The output dual drive isolation circuit works normally.

The working principle of the power conversion circuit is as follows: when the SCR drive signal is at a high level, the control chip U1 works, and through the power conversion of the transformer T1, the two secondary windings of the transformer generate pulse voltages to drive the SCR.

The working principle of the SCR dual drive isolation circuit is as follows: the pulse signal is applied to the emitter of the fifth transistor Q5 through the third capacitor C3 and the third resistor R3; the pulse signal is passed through the second comparator D2 and the third comparator D3. After reducing the voltage by 1.4V, it is added to the base of the fifth transistor Q5, and a voltage difference of 1.4V is formed between the emitter and the base of the fifth transistor Q5. At this time, the fifth transistor Q5 is turned on. The driving voltage of the SCR is generated at SCR-1G and SCR-1K. In the same way, another group of SCR driving voltages is generated in SCR-2G and SCR-2G to achieve the purpose of dual isolation driving.

Finally, it should be noted that the above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, for those skilled in the art, the The technical solutions described in the foregoing embodiments may be modified, or some technical features thereof may be equivalently replaced. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims (5)

1. a kind of SCR double drive isolation circuit module, which is characterized in that including SCR drive control circuit, circuit for power conversion and SCR double drive isolation circuit, SCR drive control circuit control the on-off of metal-oxide-semiconductor by driving signal, generate logical signal control The work of the control chip of circuit of reversed excitation processed, and then the SCR double drive isolation signals of control output end；Circuit for power conversion will be former Side 12V voltage generates two groups of equal-sized voltages after transformer isolation rectifies；SCR double drive isolation circuit will rectify after every From two groups of equal-sized voltages be added in G, K interpolar of controlled SCR respectively after decompression clamper processing, for driving The conducting of SCR.

2. SCR double drive isolation circuit module according to claim 1, which is characterized in that SCR double drive isolation circuit mould Block includes first resistor R1, second resistance R2,3rd resistor R3, the 4th resistance R4, the 5th resistance R5, the 6th resistance R6, first Metal-oxide-semiconductor Q1, the second metal-oxide-semiconductor Q2, third metal-oxide-semiconductor Q3, the 4th triode Q4, the 5th triode Q5, first diode D1, the two or two Pole pipe D2, third diode D3, the 4th diode D4, the 5th diode D5, the 6th diode D6, the 7th diode D7, the 8th Diode D8, first capacitor C1, the second capacitor C2, third capacitor C3, the 4th capacitor C4, control chip U1 and transformer T1, control Coremaking piece U1 is LM5020 chip；

SCR drive control circuit includes: that 1 foot of the second metal-oxide-semiconductor Q2 is connected with the driving signal DRV of SCR, and the 2 of the second metal-oxide-semiconductor Q2 Foot is connected with 1 foot of one end of first resistor R1, third metal-oxide-semiconductor Q3, the other end of first resistor R1 and 1 foot of control chip U1 It is connected with 4 feet ,+12V, 2 feet of third metal-oxide-semiconductor Q3 are connected with 3 feet of control chip U1,3 feet, the 3rd MOS of the second metal-oxide-semiconductor Q2 3 feet of pipe Q3 are grounded；

Circuit for power conversion and SCR double drive isolation circuit include: first capacitor C1 one end and+12V, control chip U1 1 Foot and 4 feet, one end of first resistor R1, transformer T1 1 foot be connected, the other end ground connection of first capacitor C1；Control chip U1 10 feet be connected with one end of the second capacitor C2, the other end of the second capacitor C2 ground connection；Control 9 feet and second resistance of chip U1 One end of R2 is connected, the other end ground connection of second resistance R2；Control 2 feet, 6 feet, 8 the feet ground connection of chip U1；Control the 5 of chip U1 Foot is connected with 1 foot of the first metal-oxide-semiconductor Q1, and 2 feet of the first metal-oxide-semiconductor Q1 are connected with 2 feet of transformer T1,3 feet of the first metal-oxide-semiconductor Q1 Ground connection；6 feet of transformer T1 are connected with the anode of first diode D1, the cathode of first diode D1 and the second diode D2's Anode, one end of 3rd resistor R3, third capacitor C3 one end be connected, the other end of third capacitor C3 is another with 3rd resistor R3's One end, the cathode of the 4th diode D4, the emitter of the 5th triode Q5 are connected；The cathode of second diode D2 and the three or two pole The anode of pipe D3 is connected, the anode of the cathode of third diode D3 and the 4th diode D4, the base stage of the 5th triode Q5, the 4th One end of resistance R4 is connected, and the other end of the 4th resistance R4 is connected with 5 feet of transformer T1, the end SCR-1K；5th triode Q5 Collector be connected with SCR-1G；4 feet of transformer T1 are connected with the anode of the 5th diode D5, the cathode of the 5th diode D5 It is connected with the anode of the 6th diode D6, one end of the 5th resistance R5, one end of the 4th capacitor C4, the other end of the 4th capacitor C4 It is connected with the other end of the 5th resistance R5, the cathode of the 8th diode D8, the emitter of the 4th triode Q4；6th diode D6 Cathode be connected with the anode of the 7th diode D7, the anode of the cathode of the 7th diode D7 and the 8th diode D8, the four or three The base stage of pole pipe Q4, one end of the 6th resistance R6 are connected, the other end of the 6th resistance R6 and 3 feet, the end SCR-2K of transformer T1 It is connected；The collector of 4th triode Q4 is connected with SCR-2G.

3. SCR double drive isolation circuit module according to claim 2, which is characterized in that the first metal-oxide-semiconductor Q1, the 2nd MOS Pipe Q2, third metal-oxide-semiconductor Q3 are N-type metal-oxide-semiconductor, the first metal-oxide-semiconductor Q1, the second metal-oxide-semiconductor Q2, third metal-oxide-semiconductor Q3 1 foot be grid, the One metal-oxide-semiconductor Q1, the second metal-oxide-semiconductor Q2, third metal-oxide-semiconductor Q3 2 feet be drain electrode, the first metal-oxide-semiconductor Q1, the second metal-oxide-semiconductor Q2, the 3rd MOS 3 feet of pipe Q3 are source electrode.

4. SCR double drive isolation circuit module according to claim 2, which is characterized in that the 4th triode Q4, the five or three Pole pipe Q5 is NPN type triode.

5. SCR double drive isolation circuit module according to claim 2, which is characterized in that the driving signal DRV of SCR with Dual output signal is synchronous.