阅读说明：本技术 电源输出保护控制装置 (Power output protection control device ) 是由 周波 周斌 朗代志 黄荣强 吴建军 喻雪 于 2021-08-25 设计创作，主要内容包括：本发明提供的一种电源输出保护控制装置,包括：电流检测电路,用于对直流电源的输出电流进行检测并向控制电路输出电流检测信号；电压检测电路,用于对直流电源输出的电压进行检测并输出电压检测信号至控制电路；所述控制电路,用于接收电压检测信号和电流检测信号,并在过压或者过流时向开关电路输出关断控制命令；开关电路,其电源输入端连接于电流检测电路的输出端,其电源输出端向负载供电,用于接收控制电路输出的关断控制命令执行关断操作；电源电路,其输入端连接于直流电源的输出端,其输出端向控制电路以及开关电路提供工作用电；能够对直流电的电流和电压进行准确检测,并且在过流或者过压时能够迅速执行断电保护功能。(The invention provides a power output protection control device, comprising: the current detection circuit is used for detecting the output current of the direct current power supply and outputting a current detection signal to the control circuit; the voltage detection circuit is used for detecting the voltage output by the direct-current power supply and outputting a voltage detection signal to the control circuit; the control circuit is used for receiving the voltage detection signal and the current detection signal and outputting a turn-off control command to the switch circuit when overvoltage or overcurrent occurs; the power supply input end of the switching circuit is connected with the output end of the current detection circuit, and the power supply output end of the switching circuit supplies power to the load and is used for receiving a turn-off control command output by the control circuit to execute turn-off operation; the input end of the power supply circuit is connected with the output end of the direct-current power supply, and the output end of the power supply circuit supplies working electricity to the control circuit and the switch circuit; the current and voltage of the direct current can be accurately detected, and the power-off protection function can be rapidly executed in the case of overcurrent or overvoltage.)

1. A kind of power output protects the controlling device, characterized by that: the power supply circuit comprises a current detection circuit, a switch circuit, a voltage detection circuit, a control circuit and a power supply circuit;

the power supply input end of the current detection circuit is connected with the output end of the direct-current power supply, and the power supply output end of the current detection circuit is connected with the power supply input end of the switch circuit and is used for detecting the output current of the direct-current power supply and outputting a current detection signal to the control circuit;

the voltage detection circuit is used for detecting the voltage output by the direct-current power supply and outputting a voltage detection signal to the control circuit;

the current detection input end of the control circuit is connected with the current detection circuit, and the voltage detection input end of the control circuit is connected with the voltage detection circuit and is used for receiving the voltage detection signal and the current detection signal and outputting a turn-off control command to the switch circuit when overvoltage or overcurrent occurs;

the power supply input end of the switch circuit is connected with the output end of the current detection circuit, and the power supply output end of the switch circuit supplies power to the load and is used for receiving a turn-off control command output by the control circuit to execute turn-off operation;

the input end of the power supply circuit is connected with the output end of the direct current power supply, and the output end of the power supply circuit provides working electricity for the control circuit and the switch circuit.

2. The power output protection control device according to claim 1, characterized in that: the current detection circuit comprises a resistor R1, a resistor R2, a resistor R3, a resistor R4, a resistor R5, a resistor R6, a capacitor C3, a capacitor C7 and a control chip U1;

the resistor R1 is a current detection resistor, one end of the resistor R1 is used as a power supply input end of the current detection circuit and connected with an output end of a direct current power supply, and the other end of the resistor R1 is used as a power supply output end of the current detection circuit;

the control chip U1 is an LT6108 chip, 8 pins of the control chip U1 are connected to a common connection point between the resistor R1 and the output terminal of the direct-current power supply through a resistor R3, 7 pins of the control chip U1 are connected to a common connection point between the resistor R1 and the output terminal of the direct-current power supply, one end of the resistor R2 is connected to a common connection point between the resistor R1 and the output terminal of the direct-current power supply, the other end of the resistor R2 is grounded through a resistor R4, a common connection point between the resistor R2 and the resistor R4 is connected to a 2 pin of the control chip U1, a 1 pin of the control chip U1 is connected to a resistor R1 as one end of the output terminal of a current detection circuit, a 6 pin of the control chip U1 is connected in series with a resistor R6 and then grounded, a common connection point between the resistor R5 and the resistor R6 is connected to a 5 pin of the control chip U1, a 5 pin of the control chip U1 is grounded through a capacitor C7, a 6 pin of the control chip U1 is grounded through a capacitor C3, the pin 4 of the control chip U1 is grounded, and the pin 3 of the control chip U1 serves as a detection output end of the current detection circuit.

3. The power output protection control device according to claim 1, characterized in that: the switch circuit comprises a PMOS (P-channel metal oxide semiconductor) tube Q1, a triode Q2, a triode Q3, a triode Q4, a resistor R7, a resistor R8, a resistor R9, a resistor R10, a resistor R11, a resistor R14, a resistor R15, a capacitor C4, a capacitor C5, a diode D1, a diode D2, a diode D4 and a diode D3;

the source of the PMOS transistor Q1 is used as the power input end of the switch circuit, the drain of the PMOS transistor Q1 is used as the power output end of the switch circuit, the source of the PMOS transistor Q1 is connected with the negative electrode of the voltage regulator ZD1, the positive electrode of the voltage regulator ZD1 is connected with the gate of the PMOS transistor Q1, the source of the PMOS transistor Q1 is connected with the gate of the PMOS transistor Q1 through a resistor R8, the source of the PMOS transistor Q28 is connected with one end of a capacitor C5, the other end of the capacitor C5 is connected with the gate of the PMOS transistor Q1 through a resistor R9, the source of the PMOS transistor Q1 is connected with the gate of the PMOS transistor Q637 through a capacitor C4, the gate of the PMOS transistor Q1 is connected with the positive electrode of a diode D10, the negative electrode of the diode D10 is connected with the collector of the triode Q10, the emitter of the triode Q10 is used as the first control input end of the switch circuit, the base of the triode Q10 is connected with the negative electrode of the diode D10 through a resistor R10, and the positive electrode of the power output end of the switch circuit 10;

the transistor Q2 is a P-type transistor, an emitter of the transistor Q2 is connected to a source of a PMOS transistor Q1, a collector of the transistor Q2 is connected to a gate of the PMOS transistor Q1, an emitter of the transistor Q2 is connected to a base of the transistor Q2 through a resistor R7, the base of the transistor Q2 is connected to an anode of a diode D1, a cathode of the diode D1 is connected to a collector of the transistor Q3 through a resistor R11, an emitter of the transistor Q3 is connected to the control circuit as a second control input terminal of the switching circuit, a base of the transistor Q3 is connected to a cathode of the diode D3 through a resistor R14, an anode of the diode D3 is connected to an output terminal of the power circuit, a collector of the transistor Q3 is further connected to a cathode of the diode D10, and an anode of the diode D10 is connected to a first output terminal of the voltage detection circuit as a third control terminal of the switching circuit.

4. The power output protection control device according to claim 1, characterized in that: the voltage detection circuit comprises a resistor R16, a resistor R17, a resistor R20, a resistor R19, a diode D6, a capacitor C10 and a capacitor C11;

one end of a resistor R16 is connected to an output end of a direct current power supply, the other end of a resistor R16 is connected to one end of a resistor R20 through a resistor R17, the other end of the resistor R20 is grounded, a common connection point of a resistor R16 and a resistor R17 is grounded through a capacitor C10, a common connection point of the resistor R16 and a resistor R17 is connected with a cathode of a diode D6, an anode of the diode D6 is connected to a common connection point between a resistor 17 and the resistor R20, a common connection point between the resistor 17 and a resistor R20 is grounded through a capacitor C11, a common connection point between the resistor 17 and a resistor R20 is connected with one end of a resistor R19, the other end of the resistor R19 serves as a detection output end of the voltage detection circuit, and a common connection point of the resistor R16 and a resistor R17 serves as a first output end of the voltage detection circuit.

5. The power output protection control device according to claim 1, characterized in that: the power circuit comprises a capacitor C8, a triode Q5, a resistor R12, a resistor R13, a voltage regulator tube ZD2, a capacitor C9 and a collector of a triode Q5, wherein the collector of the triode Q5 is used as the input end of the power circuit, the emitter of the triode Q5 is grounded after being connected in series with the capacitor C9 through the resistor R13, a common connection point between the capacitor C9 and the resistor R13 is used as the output end of the power circuit, the collector of the triode Q5 is grounded through the capacitor C8, the collector of the triode Q5 is connected to the base of the triode Q5 through the resistor R12, the base of the triode Q5 is connected with the negative electrode of the voltage regulator tube ZD2, and the positive electrode of the voltage regulator tube ZD2 is grounded.

6. The power output protection control device according to claim 1, characterized in that: the control circuit is a PPS3701 chip;

and a pin 4 of the control circuit is a voltage detection signal input end, a pin 3 of the control circuit is a current detection signal input end, a pin 6 of the control circuit is connected with a first control input end of the switch circuit, and a pin 1 of the control circuit is connected with a second control input end of the switch circuit.

Technical Field

The present disclosure relates to power supply control devices, and particularly to a power supply output protection control device.

Background

In a mining power supply, direct current needs to be output to provide working power for a direct current load, but the direct current needs to be kept stable and reliable in the power supply process, so that the power utilization safety of the load can be ensured.

Therefore, in order to solve the above technical problems, it is necessary to provide a new technical means.

Disclosure of Invention

In view of the above, an object of the present invention is to provide a power output protection control device, which can accurately detect the current and voltage of a direct current, can rapidly perform a power-off protection function when an overcurrent or an overvoltage occurs, and has a small turn-off spark during power-off, thereby ensuring power safety.

The invention provides a power output protection control device, which comprises a current detection circuit, a switch circuit, a voltage detection circuit, a control circuit and a power circuit, wherein the current detection circuit is connected with the switch circuit;

the power supply input end of the current detection circuit is connected with the output end of the direct-current power supply, and the power supply output end of the current detection circuit is connected with the power supply input end of the switch circuit and is used for detecting the output current of the direct-current power supply and outputting a current detection signal to the control circuit;

the voltage detection circuit is used for detecting the voltage output by the direct-current power supply and outputting a voltage detection signal to the control circuit;

the current detection input end of the control circuit is connected with the current detection circuit, and the voltage detection input end of the control circuit is connected with the voltage detection circuit and is used for receiving the voltage detection signal and the current detection signal and outputting a turn-off control command to the switch circuit when overvoltage or overcurrent occurs;

the power supply input end of the switch circuit is connected with the output end of the current detection circuit, and the power supply output end of the switch circuit supplies power to the load and is used for receiving a turn-off control command output by the control circuit to execute turn-off operation;

the input end of the power supply circuit is connected with the output end of the direct current power supply, and the output end of the power supply circuit provides working electricity for the control circuit and the switch circuit.

Further, the current detection circuit comprises a resistor R1, a resistor R2, a resistor R3, a resistor R4, a resistor R5, a resistor R6, a capacitor C3, a capacitor C7 and a control chip U1;

the resistor R1 is a current detection resistor, one end of the resistor R1 is used as a power supply input end of the current detection circuit and connected with an output end of a direct current power supply, and the other end of the resistor R1 is used as a power supply output end of the current detection circuit;

the control chip U1 is an LT6108 chip, 8 pins of the control chip U1 are connected to a common connection point between the resistor R1 and the output terminal of the direct-current power supply through a resistor R3, 7 pins of the control chip U1 are connected to a common connection point between the resistor R1 and the output terminal of the direct-current power supply, one end of the resistor R2 is connected to a common connection point between the resistor R1 and the output terminal of the direct-current power supply, the other end of the resistor R2 is grounded through a resistor R4, a common connection point between the resistor R2 and the resistor R4 is connected to a 2 pin of the control chip U1, a 1 pin of the control chip U1 is connected to a resistor R1 as one end of the output terminal of a current detection circuit, a 6 pin of the control chip U1 is connected in series with a resistor R6 and then grounded, a common connection point between the resistor R5 and the resistor R6 is connected to a 5 pin of the control chip U1, a 5 pin of the control chip U1 is grounded through a capacitor C7, a 6 pin of the control chip U1 is grounded through a capacitor C3, the pin 4 of the control chip U1 is grounded, and the pin 3 of the control chip U1 serves as a detection output end of the current detection circuit.

Further, the switch circuit comprises a PMOS tube Q1, a triode Q2, a triode Q3, a triode Q4, a resistor R7, a resistor R8, a resistor R9, a resistor R10, a resistor R11, a resistor R14, a resistor R15, a capacitor C4, a capacitor C5, a diode D1, a diode D2, a diode D4 and a diode D3;

the source of the PMOS transistor Q1 is used as the power input end of the switch circuit, the drain of the PMOS transistor Q1 is used as the power output end of the switch circuit, the source of the PMOS transistor Q1 is connected with the negative electrode of the voltage regulator ZD1, the positive electrode of the voltage regulator ZD1 is connected with the gate of the PMOS transistor Q1, the source of the PMOS transistor Q1 is connected with the gate of the PMOS transistor Q1 through a resistor R8, the source of the PMOS transistor Q28 is connected with one end of a capacitor C5, the other end of the capacitor C5 is connected with the gate of the PMOS transistor Q1 through a resistor R9, the source of the PMOS transistor Q1 is connected with the gate of the PMOS transistor Q637 through a capacitor C4, the gate of the PMOS transistor Q1 is connected with the positive electrode of a diode D10, the negative electrode of the diode D10 is connected with the collector of the triode Q10, the emitter of the triode Q10 is used as the first control input end of the switch circuit, the base of the triode Q10 is connected with the negative electrode of the diode D10 through a resistor R10, and the positive electrode of the power output end of the switch circuit 10;

the transistor Q2 is a P-type transistor, an emitter of the transistor Q2 is connected to a source of a PMOS transistor Q1, a collector of the transistor Q2 is connected to a gate of the PMOS transistor Q1, an emitter of the transistor Q2 is connected to a base of the transistor Q2 through a resistor R7, the base of the transistor Q2 is connected to an anode of a diode D1, a cathode of the diode D1 is connected to a collector of the transistor Q3 through a resistor R11, an emitter of the transistor Q3 is connected to the control circuit as a second control input terminal of the switching circuit, a base of the transistor Q3 is connected to a cathode of the diode D3 through a resistor R14, an anode of the diode D3 is connected to an output terminal of the power circuit, a collector of the transistor Q3 is further connected to a cathode of the diode D10, and an anode of the diode D10 is connected to a first output terminal of the voltage detection circuit as a third control terminal of the switching circuit.

Further, the voltage detection circuit comprises a resistor R16, a resistor R17, a resistor R20, a resistor R19, a diode D6, a capacitor C10 and a capacitor C11;

one end of a resistor R16 is connected to an output end of a direct current power supply, the other end of a resistor R16 is connected to one end of a resistor R20 through a resistor R17, the other end of the resistor R20 is grounded, a common connection point of a resistor R16 and a resistor R17 is grounded through a capacitor C10, a common connection point of the resistor R16 and a resistor R17 is connected with a cathode of a diode D6, an anode of the diode D6 is connected to a common connection point between a resistor 17 and the resistor R20, a common connection point between the resistor 17 and a resistor R20 is grounded through a capacitor C11, a common connection point between the resistor 17 and a resistor R20 is connected with one end of a resistor R19, the other end of the resistor R19 serves as a detection output end of the voltage detection circuit, and a common connection point of the resistor R16 and a resistor R17 serves as a first output end of the voltage detection circuit.

Further, the power circuit comprises a capacitor C8, a triode Q5, a resistor R12, a resistor R13, a voltage regulator tube ZD2, a capacitor C9 and a collector of a triode Q5, wherein the collector of the triode Q5 is used as an input end of the power circuit, the emitter of the triode Q5 is connected in series with the capacitor C9 through the resistor R13 and then grounded, a common connection point between the capacitor C9 and the resistor R13 is used as an output end of the power circuit, the collector of the triode Q5 is grounded through the capacitor C8, the collector of the triode Q5 is connected to the base of the triode Q5 through the resistor R12, the base of the triode Q5 is connected with the negative electrode of the voltage regulator tube ZD2, and the positive electrode of the voltage regulator tube ZD2 is grounded.

Further, the control circuit is a PPS3701 chip;

and a pin 4 of the control circuit is a voltage detection signal input end, a pin 3 of the control circuit is a current detection signal input end, a pin 6 of the control circuit is connected with a first control input end of the switch circuit, and a pin 1 of the control circuit is connected with a second control input end of the switch circuit.

The invention has the beneficial effects that: the invention can accurately detect the current and the voltage of direct current, can quickly execute the power-off protection function when in overcurrent or overvoltage, and has smaller turn-off spark in the power-off process, thereby ensuring the power utilization safety.

Drawings

The invention is further described below with reference to the following figures and examples:

FIG. 1 is a schematic structural diagram of the present invention.

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

Detailed Description

The invention is described in further detail below with reference to the drawings of the specification:

the invention provides a power output protection control device, which comprises a current detection circuit, a switch circuit, a voltage detection circuit, a control circuit and a power circuit, wherein the current detection circuit is connected with the switch circuit;

the power supply input end of the current detection circuit is connected with the output end of the direct-current power supply, and the power supply output end of the current detection circuit is connected with the power supply input end of the switch circuit and is used for detecting the output current of the direct-current power supply and outputting a current detection signal to the control circuit;

the voltage detection circuit is used for detecting the voltage output by the direct-current power supply and outputting a voltage detection signal to the control circuit;

the current detection input end of the control circuit is connected with the current detection circuit, and the voltage detection input end of the control circuit is connected with the voltage detection circuit and is used for receiving the voltage detection signal and the current detection signal and outputting a turn-off control command to the switch circuit when overvoltage or overcurrent occurs;

the power supply input end of the switch circuit is connected with the output end of the current detection circuit, and the power supply output end of the switch circuit supplies power to the load and is used for receiving a turn-off control command output by the control circuit to execute turn-off operation;

the input end of the power supply circuit is connected with the output end of the direct-current power supply, and the output end of the power supply circuit provides working electricity for the control circuit and the switch circuit; through above-mentioned structure, can carry out accurate detection to the electric current and the voltage of direct current to can carry out the power-off protection function rapidly when overcurrent or excessive pressure, and have less shutoff spark in the outage process, thereby ensure with electric safety.

In this embodiment, the current detection circuit includes a resistor R1, a resistor R2, a resistor R3, a resistor R4, a resistor R5, a resistor R6, a capacitor C3, a capacitor C7, and a control chip U1;

the resistor R1 is a current detection resistor, one end of the resistor R1 is used as a power supply input end of the current detection circuit and connected with an output end of a direct current power supply, and the other end of the resistor R1 is used as a power supply output end of the current detection circuit;

the control chip U1 is an LT6108 chip, 8 pins of the control chip U1 are connected to a common connection point between the resistor R1 and the output terminal of the direct-current power supply through a resistor R3, 7 pins of the control chip U1 are connected to a common connection point between the resistor R1 and the output terminal of the direct-current power supply, one end of the resistor R2 is connected to a common connection point between the resistor R1 and the output terminal of the direct-current power supply, the other end of the resistor R2 is grounded through a resistor R4, a common connection point between the resistor R2 and the resistor R4 is connected to a 2 pin of the control chip U1, a 1 pin of the control chip U1 is connected to a resistor R1 as one end of the output terminal of a current detection circuit, a 6 pin of the control chip U1 is connected in series with a resistor R6 and then grounded, a common connection point between the resistor R5 and the resistor R6 is connected to a 5 pin of the control chip U1, a 5 pin of the control chip U1 is grounded through a capacitor C7, a 6 pin of the control chip U1 is grounded through a capacitor C3, the pin 4 of the control chip U1 is grounded, and the pin 3 of the control chip U1 serves as a detection output end of the current detection circuit. The resistor R1 functions as a current detection circuit, and also functions as a voltage limiting and current limiting function for a subsequent switch circuit, and by the above structure, a current signal of the direct current can be accurately detected and output, wherein a capacitor C1 is further provided on the input side of the resistor R1, and a capacitor C2 is further provided on the output side of the resistor R1, as shown in fig. 2, for filtering and peak clipping.

In this embodiment, the switch circuit includes a PMOS transistor Q1, a transistor Q2, a transistor Q3, a transistor Q4, a resistor R7, a resistor R8, a resistor R9, a resistor R10, a resistor R11, a resistor R14, a resistor R15, a capacitor C4, a capacitor C5, a diode D1, a diode D2, a diode D4, and a diode D3;

the source of the PMOS transistor Q1 is used as the power input end of the switch circuit, the drain of the PMOS transistor Q1 is used as the power output end of the switch circuit, the source of the PMOS transistor Q1 is connected with the negative electrode of the voltage regulator ZD1, the positive electrode of the voltage regulator ZD1 is connected with the gate of the PMOS transistor Q1, the source of the PMOS transistor Q1 is connected with the gate of the PMOS transistor Q1 through a resistor R8, the source of the PMOS transistor Q28 is connected with one end of a capacitor C5, the other end of the capacitor C5 is connected with the gate of the PMOS transistor Q1 through a resistor R9, the source of the PMOS transistor Q1 is connected with the gate of the PMOS transistor Q637 through a capacitor C4, the gate of the PMOS transistor Q1 is connected with the positive electrode of a diode D10, the negative electrode of the diode D10 is connected with the collector of the triode Q10, the emitter of the triode Q10 is used as the first control input end of the switch circuit, the base of the triode Q10 is connected with the negative electrode of the diode D10 through a resistor R10, and the positive electrode of the power output end of the switch circuit 10;

the transistor Q2 is a P-type transistor, the emitter of the transistor Q2 is connected to the source of the PMOS transistor Q1, the collector of the transistor Q2 is connected to the gate of the PMOS transistor Q1, the emitter of the transistor Q2 is connected to the base of the transistor Q2 through a resistor R7, the base of the transistor Q2 is connected to the anode of the diode D1, the cathode of the diode D1 is connected to the collector of the transistor Q3 through a resistor R11, the emitter of the transistor Q3 is connected to the control circuit as the second control input terminal of the switching circuit, the base of the transistor Q3 is connected to the cathode of the diode D3 through a resistor R14, the anode of the diode D3 is connected to the output terminal of the power circuit, the collector of the transistor Q3 is also connected to the cathode of the diode D10, the anode of the diode D10 is connected to the first output terminal of the voltage detection circuit as the third control terminal, and, by the above structure, the timely turn-off operation can be made when the control circuit outputs a control command, therefore, the power-off protection is executed in the case of overvoltage or overcurrent, the corresponding speed is high, the turn-off spark is small, and the working stability and safety are good.

In this embodiment, the voltage detection circuit includes a resistor R16, a resistor R17, a resistor R20, a resistor R19, a diode D6, a capacitor C10, and a capacitor C11;

one end of a resistor R16 is connected to an output end of a direct current power supply, the other end of a resistor R16 is connected to one end of a resistor R20 through a resistor R17, the other end of the resistor R20 is grounded, a common connection point of a resistor R16 and a resistor R17 is grounded through a capacitor C10, a common connection point of the resistor R16 and a resistor R17 is connected to a cathode of a diode D6, an anode of a diode D6 is connected to a common connection point between a resistor 17 and the resistor R20, a common connection point between the resistor 17 and a resistor R20 is grounded through a capacitor C11, a common connection point between the resistor 17 and a resistor R20 is connected to one end of a resistor R19, the other end of the resistor R19 serves as a detection output end of the voltage detection circuit, a common connection point of a resistor R16 and a resistor R17 serves as a first output end of the voltage detection circuit, and by the above structure, a stable voltage detection signal can be provided to the control circuit, and a triode Q2, thereby ensuring the safety of the load power utilization.

In this embodiment, the power circuit includes a capacitor C8, a transistor Q5, a resistor R12, a resistor R13, a voltage regulator ZD2, a capacitor C9, and a collector of a transistor Q5 as an input terminal of the power circuit, an emitter of the transistor Q5 is connected in series through a resistor R13 and a capacitor C9 and then grounded, a common connection point between the capacitor C9 and a resistor R13 is used as an output terminal of the power circuit, a collector of the transistor Q5 is grounded through a capacitor C8, a collector of the transistor Q5 is connected to a base of the transistor Q5 through a resistor R12, a base of the transistor Q5 is connected to a negative electrode of the voltage regulator ZD2, and a positive electrode of the voltage regulator ZD2 is grounded, and by the above structure, a stable working power can be supplied to the control circuit and the switch circuit, wherein the power circuit is further provided with a diode D5 at the input terminal, as shown in fig. 2.

In this embodiment, the control circuit is a PPS3701 chip;

the control circuit has the advantages that the 4 pins of the control circuit are voltage detection signal input ends, the 3 pins of the control circuit are current detection signal input ends, the 6 pins of the control circuit are connected with the first control input end of the switch circuit, the 1 pin of the control circuit is connected with the second control input end of the switch circuit, the 5 pins of the control circuit are power supply end connection output ends of the power supply circuit, the control circuit is simple in circuit structure and low in cost, and control stability and accuracy can be guaranteed.

The working principle of the present invention is further explained in detail below:

when the direct current is input, the direct current flows through the resistor R1, then enters the switch circuit, enters the power supply circuit through the diode D5, and supplies direct current to the base electrodes of the triode Q3 and the triode Q4 after the power supply circuit carries out voltage stabilization;

because of the existence of the capacitor C5 and the capacitor C4 of the switch circuit, the capacitors C4 and C5 are charged at this time, the PMOS tube Q1 is not conducted, meanwhile, the current detection circuit samples a current signal and inputs the current signal into the control circuit, the pin 3 of the control circuit receives the current detection signal, the control circuit receives a voltage detection signal and judges whether the current and the current voltage are larger than a set value, if so, the pin 6 of the control circuit outputs a high level, the pin 1 outputs a low level, at this time, the triode Q4 is cut off, the triode Q3 is conducted, the triode Q2 is conducted, so that the PMOS tube is in a cut-off state, if the voltage and the voltage are normal, at this time, no overcurrent or overvoltage state exists, the pin 6 of the control circuit outputs a low level, the pin 1 outputs a high level, the triode Q4 is conducted, and the triode Q3 has no bias voltage between a base electrode and an emitter, then the transistor Q3 is turned off, the transistor Q2 is turned off, and when the voltages of the capacitor C4 and the capacitor C5 reach the reverse bias voltage of the PMOS transistor Q1, the PMOS transistor Q1 is turned on, so that the switch circuit supplies power to the subsequent load.

In the working process, if the control circuit monitors that overcurrent or overvoltage exists, the control circuit outputs a low level from the pin 1 to enable the triode Q3 to be conducted, so that the triode Q2 is conducted to enable the PMOS tube Q1 to be cut off, and the pin 6 of the control circuit outputs a high level to enable the triode Q4 to be cut off, so that the PMOS tube is in a stable cut-off state.

In the voltage detection circuit, the common connection point of the resistor R16 and the resistor R17 also provides a voltage signal to the collector of the transistor Q3, and the voltage signal is used for keeping the transistor Q2 turned off when the input voltage and current of the current detection module are normal, so that the Q2 is prevented from misoperation, and the stability of the whole system is ensured.

Finally, the above embodiments are only for illustrating the technical solutions of the present invention and not for limiting, although the present invention has been described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that modifications or equivalent substitutions may be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all of them should be covered in the claims of the present invention.