阅读说明：本技术 一种高可靠隔离式高压开关电路 (High-reliability isolated high-voltage switch circuit ) 是由 刘建强 俞雄伟 于 2020-04-26 设计创作，主要内容包括：本发明公开了一种高可靠隔离式高压开关电路,旨在提供一种应用在高压输入到高压输出方产品中,采用小信号控制高压器件,结构简单,安全可靠,产品应用广泛,高压除雾,照明领域,加热风扇,电机等的隔离式高压开关电路,其技术方案要点是包括：所述高压控制单元包括光耦U1和双向可控硅控制电路,所述双向可控硅控制电路包括G极接在光耦受控侧双向可控硅M1,所述积分电路的输入侧连接有控制信号输入端口P1,所述供电控制单元包括MOS管,所述MOS管的G极连接至三极管Q1的集电极,D极连接至电源VCC,S极与光耦U1的1号引脚之间接有电阻R3,S极与所述三极管Q1的发射极之间连接有电阻R12,本发明适用开关电路技术领域。(The invention discloses a high-reliability isolated high-voltage switch circuit, aiming at providing an isolated high-voltage switch circuit which is applied to a product with high voltage input to a high-voltage output side, adopts a small signal to control a high-voltage device, has simple structure, safety and reliability, wide product application, and is used in the fields of high-voltage demisting, illumination, heating fans, motors and the like, and the technical scheme main points of the isolated high-voltage switch circuit are as follows: the high-voltage control unit comprises an optical coupler U1 and a bidirectional thyristor control circuit, the bidirectional thyristor control circuit comprises a bidirectional thyristor M1 with a G pole connected to the controlled side of the optical coupler, the input side of the integrating circuit is connected with a control signal input port P1, the power supply control unit comprises an MOS (metal oxide semiconductor) tube, the G pole of the MOS tube is connected to the collector of a triode Q1, the D pole of the MOS tube is connected to a power supply VCC, a resistor R3 is connected between the S pole and a No. 1 pin of the optical coupler U1, and a resistor R12 is connected between the S pole and the emitter of the triode Q1.)

1. A high-reliability isolated high-voltage switch circuit, comprising:

the high-voltage control unit comprises an optocoupler U1 and a bidirectional thyristor control circuit, the bidirectional thyristor control circuit comprises a bidirectional thyristor M1 of which the G pole is connected to the controlled side of an optocoupler U1, the T1 pole and the T2 pole of the bidirectional thyristor receive a load control main circuit, when the optocoupler U1 is switched on, the bidirectional thyristor M1 is driven to carry load output, and when the optocoupler U1 is switched off, the bidirectional thyristor M1 is driven to switch off the load;

a pin 1 of the optocoupler U1 is connected with a first signal processing unit and a power supply control unit for electric connection, the first signal processing unit comprises an integrating circuit, the input side of the integrating circuit is connected with a control signal input port P1, the output side of the integrating circuit is connected with the base of a triode Q1, the power supply control unit comprises an MOS (metal oxide semiconductor) tube, the G pole of the MOS tube is connected to the collector of the triode Q1, the D pole of the MOS tube is connected to a power supply VCC, a resistor R3 is connected between the S pole and the pin 1 of the optocoupler U1, a resistor R12 is connected between the S pole and the emitter of the triode Q1, and when the input of the port P1 is direct current, the MOS tube is closed;

a pin 2 of the optocoupler U1 is connected with a second signal processing unit, the second signal processing unit comprises a triode Q2, a collector of the triode Q2 is connected with a pin 2 of the optocoupler U1, and a base of the triode Q2 is connected with a control signal input port P2; when the P2 input is high or low, the MOS transistor is off, the thyristor M1 is off, and no output voltage is present.

2. The high-reliability isolated high-voltage switch circuit as claimed in claim 1, wherein: the transistor Q1 is connected to the D pole of the MOS transistor through a pull-up resistor R15.

3. The high-reliability isolated high-voltage switch circuit as claimed in claim 1, wherein: a capacitor C1, a diode D2 and a resistor R2 are sequentially connected between the control signal input port P1 and the base of the triode Q1, a diode D1 is connected between the capacitor C1 and the emitter of the triode Q1, a capacitor C2 and a resistor R1 are sequentially connected between the diode D2 and the emitter of the triode Q1 in parallel, and the integrating circuit is composed of the capacitor C1, the capacitor C2 and the resistor R1.

4. The high-reliability isolated high-voltage switch circuit as claimed in claim 1, wherein: a resistor R4 is connected between the control signal input port P2 and the triode Q2, and a resistor R5 is connected between the base electrode and the emitter electrode of the triode Q2.

5. The high-reliability isolated high-voltage switch circuit as claimed in claim 1, wherein: a resistor R8 is connected between the G pole and the T1 pole of the bidirectional thyristor M1, the G pole of the bidirectional thyristor M1 is connected to the No. 4 pin of an optocoupler U1, the No. 6 pin of the optocoupler U1 is connected to the T2 pin of the bidirectional thyristor M1, a resistor R6 and a resistor R7 are sequentially connected between the No. 6 pin of the optocoupler U1 and the T2 pin of the bidirectional thyristor M1, and the T1 pin of the thyristor M1 is connected to one end of a resistor R6 through a capacitor C3.

6. The isolated high-voltage switch circuit with high reliability as claimed in claim 1, further comprising a current input port, wherein the main circuit comprises a terminal L2 connected to one side of the resistor R7 and the controlled load, a terminal L1 connected to the current input port, and an N terminal connected to the other side of the controlled load, and the other side of the load is connected to the current input port.

Technical Field

The invention relates to the technical field of switch circuits, in particular to a high-reliability isolation type high-voltage switch circuit.

Background

At present, all output control signals are basically output to a control unit in a form of single chip microcomputer output, and the core of the application solves the problem that when the control signals are abnormal or crash and run away, control is invalid, if the load cannot cut off the output in time, serious consequences at the rear end can be caused, and property and personnel casualties can be caused.

Disclosure of Invention

Aiming at the defects of the prior art, the isolating high-voltage switch circuit is applied to a product with high voltage input to a high-voltage output side, adopts a small signal to control a high-voltage device, and has the advantages of simple structure, safety, reliability, wide product application, high-voltage demisting, illumination field, heating fan, motor and the like.

In order to achieve the above object, the present invention provides the following technical solutions.

A high-reliability isolated high-voltage switching circuit, comprising:

the high-voltage control unit comprises an optocoupler U1 and a bidirectional thyristor control circuit, the bidirectional thyristor control circuit comprises a bidirectional thyristor M1 of which the G pole is connected to the controlled side of an optocoupler U1, the T1 pole and the T2 pole of the bidirectional thyristor receive a load control main circuit, when the optocoupler U1 is switched on, the bidirectional thyristor M1 is driven to carry load output, and when the optocoupler U1 is switched off, the bidirectional thyristor M1 is driven to switch off the load;

a pin 1 of the optocoupler U1 is connected with a first signal processing unit and a power supply control unit for electric connection, the first signal processing unit comprises an integrating circuit, the input side of the integrating circuit is connected with a control signal input port P1, the output side of the integrating circuit is connected with the base of a triode Q1, the power supply control unit comprises an MOS (metal oxide semiconductor) tube, the G pole of the MOS tube is connected to the collector of the triode Q1, the D pole of the MOS tube is connected to a power supply VCC, a resistor R3 is connected between the S pole and the pin 1 of the optocoupler U1, a resistor R12 is connected between the S pole and the emitter of the triode Q1, and when the input of the port P1 is direct current, the MOS tube is closed;

a pin 2 of the optocoupler U1 is connected with a second signal processing unit, the second signal processing unit comprises a triode Q2, a collector of the triode Q2 is connected with a pin 2 of the optocoupler U1, and a base of the triode Q2 is connected with a control signal input port P2; when the P2 input is high or low, the MOS transistor is off, the thyristor M1 is off, and no output voltage is present.

After adopting the structure, compared with the prior art, the high-reliability isolated high-voltage switch circuit has the following advantages: the MOS tube can output VCC power voltage to the optical coupler as long as the control signal input port P1 inputs a normally working square wave model, then the optical coupler works normally to control the loaded output of the bidirectional thyristor M1, only when the control signal input port P2 inputs a high level or a low level, the MOS tube is switched off to a non-conducting state, the thyristor at the moment is not influenced by a P2 signal, the output is in a disconnected state, and the output is no output voltage, so that the safety effect is achieved; the high-voltage defogging device is applied to a product with high voltage input to a high-voltage output side, adopts a small signal to control a high-voltage device, and has the advantages of simple structure, safety, reliability, wide product application, high-voltage defogging, the field of illumination, a heating fan, a motor and the like.

As a modification of the invention, the transistor Q1 is connected to the D pole of the MOS transistor through a pull-up resistor R15. The resistor R15 is a pull-up resistor of the triode Q1, and the main purpose is that the conduction of the MOS transistor can be controlled only when the triode Q1 is conducted in order to provide a conduction condition for the triode Q1, so that the voltage from a VCC power supply to the resistor R3 and the optocoupler U1 is realized.

As an improvement of the present invention, a capacitor C1, a diode D2 and a resistor R2 are sequentially connected between the control signal input port P1 and the base of the transistor Q1, a diode D1 is connected between the capacitor C1 and the emitter of the transistor Q1, a capacitor C2 and a resistor R1 are sequentially connected between the diode D2 and the emitter of the transistor Q1 in parallel, and the integrating circuit is composed of the capacitor C1, the capacitor C2 and the resistor R1. The capacitor C2 is charged temporarily by the high level of the square wave input by the control signal input port P1 and is converted into direct current, the capacitor C2 is full at the stage, and due to the working characteristic of the diode D2, after the forward voltage of the diode D2 is larger than the dead zone voltage, the forward current rapidly increases, the forward resistance of the diode becomes very small, and the diode is conducted in the forward direction.

As an improvement of the present invention, a resistor R4 is connected between the control signal input port P2 and the transistor Q2, and a resistor R5 is connected between the base and the emitter of the transistor Q2.

As an improvement of the invention, a resistor R8 is connected between the G pole and the T1 pole of the bidirectional thyristor M1, the G pole of the bidirectional thyristor M1 is connected to the No. 4 pin of an optocoupler U1, the No. 6 pin of the optocoupler U1 is connected to the T2 pin of the bidirectional thyristor M1, a resistor R6 and a resistor R7 are sequentially connected between the No. 6 pin of the optocoupler U1 and the T2 pin of the bidirectional thyristor M1, and the T1 pin of the thyristor M1 is connected to one end of a resistor R6 through a capacitor C3.

As a modification of the present invention, the main circuit further includes a current input port, the main circuit includes a L2 terminal connected to one side of the resistor R7 and the controlled load, a L1 terminal connected to the current input port, and an N terminal connected to the other side of the controlled load, and the other side of the load is connected to the current input port.

Drawings

Fig. 1 is a schematic diagram of a power supply circuit of the present invention.

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

Detailed Description

The invention is further described with reference to the following figures and specific examples.

Referring to fig. 1-2, a high-reliability isolated high-voltage switch circuit according to the present invention includes:

the high-voltage control unit comprises an optocoupler U1 and a bidirectional thyristor control circuit, the bidirectional thyristor control circuit comprises a bidirectional thyristor M1 of which the G pole is connected to the controlled side of an optocoupler U1, the T1 pole and the T2 pole of the bidirectional thyristor receive a load control main circuit, when the optocoupler U1 is switched on, the bidirectional thyristor M1 is driven to carry load output, and when the optocoupler U1 is switched off, the bidirectional thyristor M1 is driven to switch off the load;

a pin 1 of the optocoupler U1 is connected with a first signal processing unit and a power supply control unit for electric connection, the first signal processing unit comprises an integrating circuit, the input side of the integrating circuit is connected with a control signal input port P1, the output side of the integrating circuit is connected with the base of a triode Q1, the power supply control unit comprises an MOS (metal oxide semiconductor) tube, the G pole of the MOS tube is connected to the collector of the triode Q1, the D pole of the MOS tube is connected to a power supply VCC, a resistor R3 is connected between the S pole and the pin 1 of the optocoupler U1, a resistor R12 is connected between the S pole and the emitter of the triode Q1, and when the input of the port P1 is direct current, the MOS tube is closed;

a pin 2 of the optocoupler U1 is connected with a second signal processing unit, the second signal processing unit comprises a triode Q2, a collector of the triode Q2 is connected with a pin 2 of the optocoupler U1, and a base of the triode Q2 is connected with a control signal input port P2; when the P2 input is high or low, the MOS transistor is off, the thyristor M1 is off, and no output voltage is present.

The transistor Q1 is connected to the D pole of the MOS transistor through a pull-up resistor R15.

A capacitor C1, a diode D2 and a resistor R2 are sequentially connected between the control signal input port P1 and the base of the triode Q1, a diode D1 is connected between the capacitor C1 and the emitter of the triode Q1, a capacitor C2 and a resistor R1 are sequentially connected between the diode D2 and the emitter of the triode Q1 in parallel, and the integrating circuit is composed of the capacitor C1, the capacitor C2 and the resistor R1.

A resistor R4 is connected between the control signal input port P2 and the triode Q2, and a resistor R5 is connected between the base electrode and the emitter electrode of the triode Q2.

A resistor R8 is connected between the G pole and the T1 pole of the bidirectional thyristor M1, the G pole of the bidirectional thyristor M1 is connected to the No. 4 pin of an optocoupler U1, the No. 6 pin of the optocoupler U1 is connected to the T2 pin of the bidirectional thyristor M1, a resistor R6 and a resistor R7 are sequentially connected between the No. 6 pin of the optocoupler U1 and the T2 pin of the bidirectional thyristor M1, and the T1 pin of the thyristor M1 is connected to one end of a resistor R6 through a capacitor C3.

The main circuit comprises a L2 end connected to one side of the resistor R7 and the controlled load, a L1 end connected to the current input end port, and an N end connected to the other side of the controlled load, wherein the other side of the load is connected with the current input port.

The working principle is as follows: the diode D1 is a reflux diode, the diode D2 is a reverse current charging diode, the resistor R7, the resistor R8, the resistor R6, the resistor R2 and the resistor R15 are configuration resistors, and the capacitor C3 is a voltage spike absorption capacitor. When the output of the control signal input port P1 is normal, the control signal input port P1 is a high-low square wave type with a certain frequency, when the capacitor C2 passes through, the resistor C2 is charged temporarily by using a square wave high level and converted into direct current, the capacitor C2 is fully charged at this stage, due to the working characteristic of the diode D2, after the forward voltage of the diode D2 is greater than the dead zone voltage, the forward current rapidly increases, the forward resistance of the diode D2 becomes small, and the diode D2 is conducted in the forward direction. After conduction, a slight increase in forward voltage causes a sudden increase in forward current, and the relationship between voltage and current is approximately linear, which is called the forward conduction region. The diode D2 is mainly used to return the power to the control signal input port P1 after the power is charged. Diode D1 functions as a return current in the circuit, because diode D1 increases the return current if the voltage across capacitor C2 is to reach a desired level, resistor R15 is a pull-up resistor of transistor Q1, and mainly aims to provide a conduction condition for transistor Q1, transistor Q1 is turned on to control the conduction of MOS transistors, so as to implement the voltage operation from the power source VCC to resistors R3 and U1, and resistor R2 consumes the energy on capacitor C2. Here, the resistance values or capacitance values of the resistor R15, the resistor R12 and the capacitor C2 can be adjusted, the resistance value of the resistor R15 is adjusted to reduce the shunt current on the resistor R15, so that the charging time of the capacitor C2 in the circuit is accelerated, and the resistor R12 also plays a very important role in the circuit, so that when the input of the control signal input port P1 is direct current, the energy on the capacitor C2 can be consumed through the resistor R12, and the MOS transistor is turned off. As long as our control signal input port P1 is when the square wave model of normal work, the MOS pipe just can be exported power VCC voltage for opto-coupler U1, then opto-coupler U1 does normally just can export the on-load output of bidirectional thyristor altogether, the MOS pipe is cut to non-conducting state when only control signal input port P2 input is high level or low level, bidirectional thyristor at this moment is not controlled signal input port P2's influence, the output is off-state, output this moment is no output voltage thereby reach the safety action.

The above is only a preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above-mentioned embodiments, and all technical solutions belonging to the idea of the present invention belong to the protection scope of the present invention. It should be noted that modifications and embellishments within the scope of the invention may occur to those skilled in the art without departing from the principle of the invention, and are considered to be within the scope of the invention.