CN116231594A

CN116231594A - Third party detects and quick response's power protection circuit

Info

Publication number: CN116231594A
Application number: CN202310291382.7A
Authority: CN
Inventors: 戴庆
Original assignee: Suzhou Pyle Electric Co ltd
Current assignee: Suzhou Pyle Electric Co ltd
Priority date: 2023-03-23
Filing date: 2023-03-23
Publication date: 2023-06-06

Abstract

The invention relates to the technical field of power protection, in particular to a power protection circuit for third party detection and quick response, which comprises a voltage and current sampling circuit, an analog-to-digital conversion circuit, a voltage comparison circuit, a data processing circuit, an isolation protection circuit and a peripheral port circuit, wherein the voltage comparison circuit is used for detecting the voltage and the current of the power protection circuit; the voltage and current sampling circuit collects voltage and current signals between the power supply equipment and the load equipment; the data processing circuit judges whether the voltage of the load equipment end exceeds the limit according to the comparison result of the sampling voltage and the reference voltage in the voltage comparison circuit, and the power supply equipment is turned off and protected through the peripheral port circuit when the voltage exceeds the limit. The invention monitors the power supply and the electric equipment in real time and responds quickly by setting the voltage, the current sampling, the voltage comparator, the controller and the peripheral port circuit, is suitable for various electric equipment, has high circuit precision and low cost, and protects the circuit from overvoltage and overcurrent damage by setting the isolation protection circuit and the first and second protection units.

Description

Third party detects and quick response's power protection circuit

Technical Field

The invention relates to the technical field of power protection, in particular to a power protection circuit for third party detection and quick response.

Background

In the use process of the circuit, the load end changes to generate larger reverse voltage or current, and the unstable reverse voltage or current is easy to damage a power supply or a sensitive load, so that equipment is damaged. Therefore, a power protection circuit is often required to be provided in the hardware circuit.

In the prior art, an overvoltage detection circuit is additionally arranged between a power supply and equipment, and when an overvoltage phenomenon occurs, the power supply is cut off in time so as to protect electric equipment from being damaged; in the existing overvoltage detection circuit, a triode is often used for clamping voltage drop of output voltage, so that overvoltage suppression is realized, and the circuit is protected.

However, the existing power supply protection circuit adopts three diodes to realize overvoltage suppression, the response to the voltage and current is regulated and responded mostly at microsecond level, the voltage and current resistant time requirements of power supply equipment or a load end are difficult to meet in practice, and the protection effect is not thorough. Therefore, there is a need for providing real-time detection of voltage and current at the output terminal or load terminal and for rapidly suppressing or blocking the generated overvoltage or overcurrent.

Disclosure of Invention

The invention aims at: the power supply protection circuit for third party detection and quick response is provided, so that the problem that the response speed of the power supply protection circuit in the prior art is difficult to meet the voltage-resistant and current-resistant time requirements of power supply equipment or loads due to the fact that a triode is adopted for overvoltage suppression is solved.

The technical scheme of the invention is as follows:

the power supply protection circuit comprises a third party detection and quick response power supply protection circuit, a voltage sampling circuit, a current sampling circuit, an analog-to-digital conversion circuit, a voltage comparison circuit, a data processing circuit, an isolation protection circuit and a peripheral port circuit;

the input ends of the voltage sampling circuit and the current sampling circuit are respectively connected between power supply equipment and load equipment, and the output ends of the voltage sampling circuit and the current sampling circuit are respectively connected with the input end of the analog-to-digital conversion circuit and the input end of the voltage comparison circuit; the analog-to-digital conversion circuit, the voltage comparison circuit and the peripheral port circuit are respectively connected with the data processing circuit;

the analog-to-digital conversion circuit is used for respectively converting the sampling voltage and the sampling current into digital signals and transmitting the digital signals to the data processing circuit; the voltage comparison circuit compares sampling results of the voltage sampling circuit and the current sampling circuit with reference voltages preset in the voltage comparison circuit respectively, the comparison results are transmitted to the data processing circuit, the data processing circuit judges whether the voltage of a load equipment end exceeds the limit according to the output result of the voltage comparison circuit, the power supply equipment and a load are cut off and protected through the peripheral port circuit when the voltage exceeds the limit, and the isolation protection circuit performs isolation protection on a main control chip of the data processing circuit when the data processing circuit is in communication with the outside.

Preferably, the data processing circuit comprises a controller U13 and a communication circuit, and the peripheral port circuit comprises an input peripheral circuit and an output peripheral circuit; the power supply device or the load device, the input peripheral circuit, the controller U13 and the output peripheral circuit form a closed loop for controlling the power supply and the load to be turned off, and the communication circuit is used for communication between the load device and the controller U13.

Preferably, the voltage comparison circuit includes a voltage comparator U8, a first protection unit and a second protection unit, where the voltage comparator U8 has a first input terminal, a second input terminal, a third input terminal, a fourth input terminal, a first output terminal and a second output terminal;

the output end of the current sampling circuit is connected with the third input end of the dual-voltage comparator U8 through a thirty-ninth resistor; the fourth input end is grounded through a forty-eight resistor; the fourth input end is connected with a power supply through a forty-third resistor;

the output end of the voltage sampling circuit is connected with the first input end of the dual-voltage comparator U8 through a thirty-eighth resistor, the second input end is grounded through a forty-sixth resistor, the second input end is connected with a power supply through a forty-sixth resistor, and the second input end is connected with the data processing circuit;

The first protection unit is connected with the first output end, and the second protection unit is connected with the second output end.

Preferably, the first protection unit includes a first diode, a second diode, a thirty-fourth resistor, and a thirty-fifth resistor;

the first diode and the second diode are connected in reverse series, the thirty-fourth resistor is connected in series between the negative electrodes of the first diode and the second diode, the positive electrode of the first diode is connected with a power supply, and the positive electrode of the second diode is connected with the data processing circuit through the thirty-fifth resistor; a second output end of the dual-voltage comparator is connected between the second diode and the thirty-fourth resistor;

the second protection unit comprises a third diode, a fourth diode, a thirty-sixth resistor and a thirty-seventh resistor;

the third diode and the fourth diode are connected in reverse series, the thirty-seventh resistor is connected in series between the third diode and the negative electrode of the fourth diode, the positive electrode end of the fourth diode is connected with a power supply, the positive electrode of the third second stage is connected to the data processing circuit through the thirty-sixth resistor, and the first output end of the dual-voltage comparator U8 is connected between the third diode and the thirty-seventh resistor.

Preferably, the isolation protection circuit comprises a dual-channel digital isolator U9, a first photoelectric coupler U11, a second photoelectric coupler U12 and a low-power-consumption transceiver U10, wherein the low-power-consumption transceiver U10 is connected with the communication circuit through a connector;

the negative electrode of the first photoelectric coupler U11 and the negative electrode of the second photoelectric coupler U12 are respectively connected with two input/output pins on the controller U13 in a one-to-one manner; the second logic input end of the double-channel digital isolator U9 is connected with the controller U13 through a forty-fifth resistor in series; the first logic output end of the double-channel digital isolator U9 is connected with the controller U13 through a forty-second resistor in series;

the emitter of the first photoelectric coupler U11 is connected with the receiver output enabling end of the low-power-consumption transceiver U10 through a fifty-second resistor in series, and the emitter of the second photoelectric coupler U12 is connected with the driver output enabling end of the low-power-consumption transceiver U10 through a fifty-fifth resistor in series;

the first logic input end of the dual-channel digital isolator U9 is connected with the output end of the low-power-consumption transceiver U10, and the second logic output end of the dual-channel digital isolator U9 is connected with the driver input end of the low-power-consumption transceiver U10.

Preferably, the isolation protection circuit further comprises an electrostatic protector, a forty-seventh resistor, a forty-ninth resistor, a forty-first resistor, a forty-fourth resistor, a fifty-first resistor, and a first switch;

one end of the forty-seventh resistor, one end of the forty-ninth resistor, one end of the first switch and a second pin end of the electrostatic protector are all connected to a non-inverting input end of a driver output button receiver of the low-power-consumption transceiver U10, the other end of the forty-seventh resistor is connected to a low-level end of a communication circuit, the other end of the forty-ninth resistor is connected with a power supply, and the other end of the first switch is connected in series with the forty-first resistor;

the other end of the forty-first resistor, one end of the forty-fourth resistor, one end of the fifty-first resistor and the first pin end of the electrostatic protector are all connected to the driver output/receiver inverting input end of the low-power transceiver U10, the other end of the forty-fourth resistor is connected to the high-level end of the communication circuit, and the other end of the fifty-first resistor and the third pin end of the electrostatic protector D6 are grounded.

Preferably, the input peripheral circuit comprises a third photo coupler U14, a fifty-seventh resistor, a fifty-eighth resistor and a fifty-ninth resistor, wherein the fifty-seventh resistor is a current limiting resistor, and the fifty-eighth resistor is a protection resistor;

The emitter of the third photoelectric coupler U14 is connected with the controller U13 through the fifty-ninth resistor in series, the positive electrode of the third photoelectric coupler U14 is connected to the high-level end of the load equipment through the fifty-seventh resistor, the negative electrode of the third photoelectric coupler U14 is connected to the high-level end of the load equipment, and the fifty-eighth resistor is connected between the positive electrode and the negative electrode of the third photoelectric coupler U14;

preferably, the output peripheral circuit comprises a fourth photoelectric coupler U15, a sixty-first resistor, a sixty-second resistor, a seventh diode and a first triode;

the negative electrode of the fourth photoelectric coupler U15 is connected with the controller U13, the emitter of the fourth photoelectric coupler U15 is connected with the low-level end of the load equipment, and the emitter of the fourth photoelectric coupler U15 is connected with the high-level end of the load equipment through the seventh diode;

the base electrode of the first triode is connected with the collector electrode of the fourth photoelectric coupler U15 through a sixty-two resistor in series connection, the base electrode of the first triode is connected with the emitter electrode of the first triode through a sixty-one resistor, and the collector electrode of the first triode is connected with the high-level end of load equipment.

Preferably, the voltage sampling circuit comprises a first voltage division module, an isolation difference module U2 and a first operational amplification module which are sequentially connected; the first voltage division module is connected between the power supply equipment and the load equipment through a connector U3 and is used for dividing the acquired voltage signals, and the isolation differential module U2 and the first operational amplification module isolate and amplify the divided voltage signals and output single-ended voltage sampling signals;

the current sampling circuit comprises a Hall sensor, a second voltage dividing module and a voltage follower which are sequentially connected, and the voltage follower carries out equivalent stable output on the signals subjected to voltage dividing and voltage drop so as to obtain voltage sampling signals of the current sampling circuit;

the first voltage dividing module and the second voltage dividing module adopt a resistor voltage dividing mode for voltage division.

Preferably, the analog-to-digital conversion circuit comprises an analog-to-digital converter U1 and a voltage reference module connected to the analog-to-digital converter U1, wherein the voltage reference module is provided with a voltage reference for limiting the dynamic range of the sampling voltage, and the first operational amplification module and the analog-to-digital converter U1 are provided with the same reference ground;

The voltage reference module comprises a voltage reference chip U7, a first inductor, a twelfth capacitor, a thirteenth capacitor, a fourteenth capacitor and a fifteenth capacitor;

the input end of the voltage reference chip U7 is externally connected with a power supply and is grounded through a fifteenth capacitor, the output end of the voltage reference chip U7 is connected with one end of a first point inductor and one end of a twelfth capacitor, and the other end of the inductor, one end of the thirteenth capacitor and one end of the fourteenth capacitor are respectively connected to the analog-to-digital converter U1; one end of the twelfth capacitor, the thirteenth capacitor and the fourteenth capacitor are respectively connected to the ground pin of the voltage reference chip U7.

Compared with the prior art, the invention has the advantages that:

(1) According to the power supply device, detection of current and voltage output by a power supply load end is achieved through the voltage and current sampling circuit, the analog-to-digital conversion circuit, the voltage comparison circuit, the data processing circuit, the peripheral port circuit and the isolation protection circuit, and a plurality of groups of switching diodes and optocouplers are arranged in the voltage comparison circuit, the peripheral port circuit and the isolation protection circuit, nanosecond response is made when an overvoltage condition is detected, and power supply equipment and/or load are rapidly protected.

(2) According to the voltage comparator, the first protection unit and the second protection unit are arranged outside the voltage comparator, the isolation protection circuit is arranged between the controller and the communication circuit, and the protection circuit can be prevented from being damaged by overvoltage or overcurrent while the power supply and the load equipment are protected.

(3) The voltage comparator is provided with a first voltage dividing module, a second voltage dividing module, a plurality of circuit selection dry nodes, load equipment capable of adaptively detecting and controlling different voltages, voltage comparator reference voltage adaptability is adjustable, and circuit compatibility is strong.

(4) The circuit components and the chip of the application take low cost and high precision as selection principles, and have low cost and high precision.

Drawings

The invention is further described below with reference to the accompanying drawings and examples:

FIG. 1 is a schematic block diagram of a power protection circuit according to an embodiment of the present invention;

fig. 2 is a circuit diagram of a voltage sampling circuit according to an embodiment of the present invention;

FIG. 3 is a circuit diagram of a current sampling circuit according to an embodiment of the present invention;

FIG. 4 is a circuit diagram of a voltage reference module according to an embodiment of the present invention;

fig. 5 is a partial chip circuit diagram of a high-pass analog-to-digital converter according to an embodiment of the present invention;

fig. 6 is a partial chip circuit diagram of a low-pass analog-to-digital converter according to an embodiment of the present invention;

FIG. 7 is a circuit diagram of a voltage comparison circuit according to an embodiment of the present invention;

FIG. 8 is a circuit diagram of an isolation protection circuit according to an embodiment of the present invention;

fig. 9 is a circuit diagram of a peripheral port circuit according to an embodiment of the present invention;

FIG. 10 is a schematic diagram of a controller chip of a data processing circuit according to an embodiment of the present invention;

wherein: 1. a voltage sampling circuit; 2. a current sampling circuit; 3. an analog-to-digital conversion circuit; 4. a voltage comparison circuit; 5. a data processing circuit; 6. a peripheral port circuit; 7. an isolation protection circuit;

11. a first voltage dividing module; 12. isolating the differential module; 13. a first operational amplification module;

21. a hall sensor; 22. a second voltage dividing module; 23. a voltage follower;

32. a voltage reference module; 42. a first protection unit; 43. a second protection unit;

61. inputting a peripheral circuit; 62. and outputting the peripheral circuit.

Detailed Description

The following describes the present invention in further detail with reference to specific examples:

as shown in fig. 1, a third party detection and fast response power protection circuit comprises a voltage sampling circuit 1, a current sampling circuit 2, an analog-to-digital conversion circuit 3, a voltage comparison circuit 4, a data processing circuit 5, an isolation protection circuit 7 and a peripheral port circuit 6.

The input ends of the voltage sampling circuit 1 and the current sampling circuit 2 are respectively connected between the power supply equipment and the load equipment, and the output ends of the voltage sampling circuit 1 and the current sampling circuit 2 are respectively connected with the input end of the analog-to-digital conversion circuit 3 and the input end of the voltage comparison circuit 4; the analog-digital conversion circuit 3, the voltage comparison circuit 4 and the peripheral port circuit 6 are respectively connected with the data processing circuit 5.

The analog-digital conversion circuit 3 converts the sampling voltage and the sampling current into digital signals respectively and transmits the digital signals to the data processing circuit 5; the voltage comparison circuit 4 compares the sampling results of the voltage sampling circuit 1 and the current sampling circuit 2 with preset comparison voltages respectively, and transmits the comparison results to the data processing circuit 5, and the data processing circuit 5 judges whether the voltage of the load equipment end exceeds the limit according to the output result of the voltage comparison circuit 4, and performs turn-off protection on the power supply equipment through the peripheral port circuit 6 when the voltage exceeds the limit.

The embodiment of the invention is used as a power supply protection circuit for third party detection and response, is suitable for electric equipment in a weak current control strong current mode, the first voltage division module 11 is connected between power supply equipment and load equipment through the connector U3, the power supply equipment load equipment is powered at high voltage with the magnitude of more than kilovolts, and is suitable for industrial control equipment for factory line production and remote voltage transmission control.

Therefore, the high-voltage large current obtained by voltage and current sampling needs to be reduced and converted and then is transmitted to the control chip.

The voltage sampling circuit 1 comprises a first voltage division module 11, an isolation difference module 12 and a first operational amplification module 13; the first voltage division module 11 is configured to divide the obtained voltage signal, the isolation differential module 12 performs noise suppression and differential amplification on the obtained divided voltage signal, and the operational amplification module 13 converts the signal of the isolated differential output into a single-ended signal, so as to facilitate analog-to-digital conversion.

The first voltage dividing module 11 is configured to divide voltages by resistors, and includes two paths of resistors in series-parallel connection, where each path of resistor includes a plurality of equivalent resistors, and an embodiment of a circuit diagram of voltage sampling is shown in fig. 2:

the input ends of the two paths of series-parallel resistors are respectively connected with a high-level end and a low-level end of power supply equipment through a connector U13; one path of the resistor is sequentially connected with a second resistor R2, a third resistor R3, a fourth resistor R4, a fifth resistor R5 and a sixth resistor R6 in series, and the other path of the resistor is sequentially connected with a tenth resistor R10, an eleventh resistor R11, a twelfth resistor R12, a thirteenth resistor R13 and a fourteenth resistor R14 in series.

All chips and components of the embodiment of the invention are selected on the basis of low cost and high precision.

The isolated differential module 12 comprises a second chip U2, a fifteenth resistor R15, a sixteenth resistor R16 and a fourth capacitor C4; one end of the sixth resistor R6, one end of the fifteenth resistor R15 and one end of the fourth capacitor C4 are connected to the positive input end of the second chip U2; the other end of the fourteenth resistor R14, the other end of the fifteenth resistor R15, the other end of the fourth capacitor C4 and one end of the sixteenth resistor R16 are all connected to the reverse input end of the second chip U2, the other end of the sixteenth resistor R16 is connected to the input end of the second chip U2 and the input end of the sixteenth resistor R16 is grounded, and the output end of the second chip U2 is grounded and connected to analog ground.

In principle, the type of the chip U2 is not limited, and the selection is specifically performed according to the use requirements of customers, such as 78 series chips, 7800 chips and 7804 chips.

The sixteenth resistor R16 is a reserved resistor and a reserved dry node (not specifically shown in the drawing), and is selected according to the use requirement, and the voltage sampling circuit does not perform differential operational amplification when the client power supply terminal is at a low voltage such as one hundred volts, and the sixteenth resistor R16 is directly connected to digital ground, which is equivalent to directly taking the voltages at two ends of the fifteenth resistor R15 as sampling voltages; the client power supply end is high voltage, such as more than one kilovolt, the sixteenth resistor R16 is used for dividing voltage in the circuit, the voltage at two ends of the fifteenth resistor R15 is intercepted to obtain a divided voltage signal, and sampling voltage is output after isolation difference and operational amplification.

The first operational amplifier module 13 comprises an operational amplifier chip U4B, a first resistor R1, a seventh resistor R7, an eighth resistor R8, a ninth resistor R9, a seventeenth resistor R17, a first capacitor C1, a fifth capacitor C5 and a sixth capacitor C6, wherein the U4B adopts an OPA2277UA operational amplifier to filter and stabilize the acquired voltage signals; the seventh resistor R7 is connected between the reverse output end of the second chip U2 and the reverse input end of the operational amplifier chip U4B, the ninth resistor R9 is connected between the forward output end of the second chip U2 and the forward input end of the operational amplifier chip U4B, the first resistor R1 is used as a feedback resistor to be connected between the reverse input end of the operational amplifier chip U4B and the output end of the operational amplifier chip U4B, and the first capacitor C1 is connected in parallel with the two ends of the first resistor R1; one end of the seventeenth resistor R17 is linked with the positive input end of the operational amplifier chip U4B, the other end of the seventeenth resistor R17 is connected with analog ground, and the sixth capacitor C6 is connected in parallel with the two ends of the seventeenth resistor R17; one end of the eighth resistor R8 is connected to the output end of the operational amplifier chip U4B, the other end of the eighth resistor R8 is a voltage sampling output end used for connecting an analog-to-digital conversion circuit and a voltage comparison circuit, one end of the fifth capacitor C5 is connected to the other end of the eighth resistor R8, and the other end of the fifth capacitor C5 is connected to analog ground.

The current sampling circuit 2 includes a hall sensor 21, a second voltage dividing module 22, and a voltage follower 23; the hall sensor 21 is connected to the tested circuit, and the output voltage signal reflects the sampled current, because the voltage signal is collected, the smaller the current flowing through the circuit is, the better the current is, the higher the voltage signal output by the hall sensor 21 is, after being divided, the higher the voltage signal is output (the impedance is increased and the current is reduced) by one to one through the voltage follower 23, and then the higher the voltage signal is input to the voltage comparison circuit 4 and the analog-to-digital conversion circuit 3.

The Hall sensor 21 is connected with positive and negative 15-volt power supplies and is connected with analog ground through a twenty-first resistor R21.

The voltage follower 23 includes an operational amplifier chip U4A, an eighteenth resistor R18, a nineteenth resistor R19, a twentieth resistor R20, an eighth capacitor C8, and a tenth capacitor C10, where the U4A is an OPA2277UA operational amplifier.

The output end of the Hall sensor 21 is connected to the positive input end of the operational amplification chip U4A through a twenty-first resistor R20 in series; one end of the tenth capacitor C10 is connected with the positive input end of the operational amplifier chip U4A, and the other end of the tenth capacitor C is connected with analog ground; an eighteenth resistor R18 of a feedback resistor is connected between the inverting input end and the output end of the operational amplification chip U4A, the operational amplification chip U4A is connected in series with the nineteenth resistor to output sampling current, and the current sampling output end is grounded through an eighth capacitor C8.

The current collected by the Hall sensor 21 is different in size, and the sampling voltage is always ensured to be smaller than the voltage reference of the voltage reference module 23, so that the voltage needs to be reduced in a voltage division mode; the second voltage dividing module 22 is configured as a resistor voltage divider, and includes four resistors connected in series and parallel, each resistor includes a plurality of equivalent resistors, the same side ends of the four resistors are commonly grounded, and the other same side ends of the four resistors are commonly coupled between the hall sensor U6 and the twentieth resistor R20.

The specific connection mode is shown in fig. 3: the first path of resistor comprises a twenty-second resistor R22, a twenty-sixth resistor R26 and a thirty-first resistor R30 which are sequentially connected in series; the second path of resistor comprises a twenty-third resistor R23, a twenty-seventh resistor R27 and a thirty-first resistor R31 which are sequentially connected in series; the third resistor comprises a twenty-fourth resistor R24, a twenty-eighth resistor R28 and a thirty-second resistor R32 which are sequentially connected in series; the fourth path of resistor comprises a twenty-fifth resistor R25, a twenty-ninth resistor R29 and a thirty-third resistor R33; one end of a twenty-second resistor R22, a twenty-third resistor R23, a twenty-fourth resistor R24 and a twenty-fifth resistor R25 are commonly connected to the output end of the Hall sensor 21; one end of each of the thirty-first resistor R30, the thirty-first resistor R31, the thirty-second resistor R32, and the thirty-third resistor R33 is connected to analog ground.

The analog-digital conversion circuit 3 comprises an analog-digital converter U1 and a voltage reference module 32 connected to the analog-digital converter U1, the voltage reference module 32 is provided with a voltage reference for limiting the dynamic range of the sampling voltage, and the operational amplification module U4B and the analog-digital converter U1 are provided with the same reference ground.

The reference voltage of the voltage reference module 32 is dynamically adjustable, the lower the voltage reference is, the smaller the dynamic range is, the higher the voltage reference is, the larger the dynamic range is, the more accurate the accuracy is, and the sampling accuracy is controlled by adjusting the reference voltage of the voltage reference module 32.

The analog-to-digital conversion circuit of the analog-to-digital conversion circuit 3 can be a high-pass conversion circuit and a low-pass conversion circuit, and as shown in fig. 5, a schematic diagram of local structural connection of an analog conversion chip U1 in the high-pass conversion circuit is provided; a schematic diagram of the local structural connection of the analog conversion chip U5 in the low-pass conversion circuit is given in fig. 6; u1 and U5 external crystal oscillator circuit respectively, U1 and U5 ground pin all ground analog ground respectively, U5's reverse reference voltage pin ground reference ground, U5's power end passes through eleventh electric capacity C11 ground analog ground.

U1 is selected from AD7190BRUZ-REEL chip, and U5 is selected from TM7705 chip. When the circuit is specifically used, the high-pass U1 and/or the low-pass U5 are/is selected for conversion according to actual needs, so that different requirements are met, and the circuit compatibility is improved.

The voltage reference module 32 includes a voltage reference chip U7, a first inductor, a twelfth capacitor, a thirteenth capacitor, a fourteenth capacitor, and a fifteenth capacitor; as shown in fig. 4, a circuit connection embodiment of the voltage reference module 32 is given:

the input end of the voltage reference chip U7 is externally connected with a power supply and is grounded through a fifteenth capacitor C15, one end of a first point inductor L1 and one end of a twelfth capacitor C12 are both connected with the output end of the voltage reference chip U7, the other end of the first inductor L1 is the output end (connected with an analog conversion chip) of the voltage reference module 32, and one ends of a thirteenth capacitor C13 and a fourteenth capacitor C14 are respectively connected with the other end of the first inductor L1, namely the output end of the voltage reference module 32; the other end of the twelfth capacitor C12, the other end of the thirteenth capacitor C13, and the other end of the fourteenth capacitor C14 are respectively connected to the ground pin of the voltage reference chip U7.

The embodiment of the invention rapidly responds to the overvoltage phenomenon of the circuit by arranging the hardware comparison circuit and the peripheral port circuit.

The voltage comparator is provided with a reference voltage in advance, compares the sampling voltage and the sampling current with the preset reference voltage, judges whether the circuit is over-voltage or over-current, and outputs the comparison result to the data processing circuit 5 in the form of high and low level (digital signals), and the data processing circuit 5 controls the external equipment (including a power supply) to be turned on and off through the peripheral port circuit 6 so as to protect the circuit.

When the voltage comparator is specifically used, a customer can change the reference voltage of the voltage comparator through a communication circuit, an external industrial control screen, a computer end and the like.

In this embodiment, the digital signal output by the controller U13 is used as an adjustable reference voltage for comparing the current, so as to set the overvoltage value for the customer in different application scenarios.

In detail, the voltage comparison circuit 4 includes a voltage comparator U8, a first protection unit 42 and a second protection unit 43, where the voltage comparator U8 is a dual-voltage comparator, and has four input ports, specifically, a first input port, a second input port, a third input port, and a fourth input port.

The voltage comparator U8 is an LM393DR dual-voltage comparator integrated circuit, a first input end of the voltage comparator U8 corresponds to a first reverse input end, a second input end corresponds to a first forward input end, a third input end corresponds to a second reverse input end, and a fourth input end corresponds to a second forward input end.

As shown in fig. 7, a specific implementation circuit diagram of the voltage comparator U8 voltage comparison circuit 4 is shown in the following specific connection relationship:

the output end of the current sampling circuit 2 is connected with the third input end of the dual-voltage comparator U8 through a thirty-ninth resistor R39; the fourth input end is grounded through a forty-eight resistor R48; the fourth input end is connected with a 15-volt power supply through a forty-third resistor R43; the power pin of the voltage comparator U8 is connected with a 15-volt power supply, and the ground pin is connected with a-15-volt power supply.

The output end of the voltage sampling circuit 1 is connected with the first input end of the dual-voltage comparator U8 through a thirty-eighth resistor R38, the second input end is grounded through a forty-sixth resistor R46, the second input end is connected with a 15-volt power supply through a forty-sixth resistor R40, and the second input end is connected with the data processing circuit 5 (PA 5 port).

The first protection unit 42 is connected to the first output terminal of the voltage comparator U8, and the second protection unit 43 is connected to the second output terminal of the voltage comparator U8.

The first protection unit 42 includes a first diode D1, a second diode D2, a thirty-fourth resistor R34, and a thirty-fifth resistor R35.

The first diode D1 and the second diode D2 are connected in reverse series, the thirty-fourth resistor R34 is connected in series between the cathodes of the first diode D1 and the second diode D2, the anode of the first diode D1 is connected with a 15-volt power supply, and the anode of the second diode D2 is connected with the data processing circuit 5 (the port of the PA 10) through a thirty-fifth resistor R35; the second output of the dual voltage comparator 41 is connected between the second diode D2 and the thirty-fourth resistor R34.

The LM393DR dual-voltage comparator selected by the voltage comparator U8 has no pull-up resistor inside, and the thirty-fourth resistor R34 is the pull-up resistor of the voltage comparator U8, so that the driving capability (increasing current) is improved, and the requirement of outputting high level is met.

A thirty-fifth resistor R35 limits the current of the circuit; the voltage comparator U8 is externally connected with a 15-volt power supply, but the internal voltage of the voltage comparator is about 3.3 volts, and clamping voltage is formed by arranging the first diode D1 and the second diode D2 and is integrated on the second output end (seventh pin) of the voltage comparator U8 so as to meet the use requirement of the chip, and the chip is protected.

Meanwhile, the voltage comparator U8 detects whether the voltage output is at a low level or at a high level through the thirty-fifth resistor R35 and the second diode D2, so that whether the voltage signal acquired by the current sampling circuit is overvoltage or not is judged.

The second protection unit 43 includes a third diode D3, a fourth diode D4, a thirty-sixth resistor R36, and a thirty-seventh resistor R37.

The third diode D3 and the fourth diode D4 are connected in reverse series, the thirty-seventh resistor R37 is connected in series between the cathodes of the third diode D3 and the fourth diode D4, the anode of the fourth diode D4 is connected to a 15 volt power supply, the anode of the third diode D3 is connected to the data processing circuit 5 (PA 11 (PA 9) port) through the thirty-sixth resistor R36, and the first output terminal of the dual-voltage comparator U8 is connected between the third diode D3 and the thirty-seventh resistor R37.

Similarly to the first protection unit 42, the thirty-sixth resistor R36 in the second protection unit is a pull-up resistor, the thirty-seventh resistor R37 is a current-limiting resistor, and the third diode D3 and the fourth diode D4 are connected in reverse series to form a clamp voltage, and are integrated into the first output end (the first pin) of the voltage comparator U8 to meet the use requirement of the chip, and protect the chip.

Meanwhile, the voltage comparator U8 detects whether the voltage output is at a low level or at a high level through the thirty-sixth resistor R36 and the third diode D3, so that whether the current collected by the voltage sampling circuit is overcurrent or not is judged.

A fifth diode D5 is provided between the cathode terminal of the third diode D3 and the thirty-seventh resistor R37, the cathode of the fifth diode D5 is connected to the cathode terminal of the third diode D3, and the anode of the fifth diode is suspended (high level).

The first diode D1, the second diode D2, the third diode D3, the fourth diode D4 and the fifth diode D5 are respectively small single-switch diodes with model number LL 4148.

The voltage comparison result (transmitted to the controller U13) is obtained stably, safely and quickly through the double-voltage comparator U8 and the first protection unit 42 and the second protection unit 43 which are arranged outside, and the overvoltage and overcurrent phenomena are responded quickly through the photoelectric conversion effect of the photoelectric coupler.

The data processing circuit 5 includes a controller U13 and a memory, where the controller U13 is a high-speed embedded memory, and in this embodiment, an Arm microprocessor with a model number STM32G071C876 is selected, and a partial chip circuit diagram is shown in fig. 10.

The state of the sampling voltage and the sampling current is recorded in the memory, the controller U13 is connected with the peripheral equipment such as an industrial control screen through a communication circuit, the sampling voltage and the sampling current are output and displayed in a waveform form, and an operator calls out past data through the external industrial control screen and checks the output waveform to judge whether the generation time and the generated amplitude of the overvoltage and overcurrent conditions meet the technical requirements of the negative terminal. The communication circuit can be a 485 communication isolation circuit, and is connected with an upper computer or a direct current power supply system through the 485 communication circuit so as to set various parameters of circuit equipment.

The peripheral port circuit 6 includes an input peripheral circuit 61 and an output peripheral circuit 62; the load device, the input peripheral circuit 61, the controller U13, and the output peripheral circuit 62 form a closed loop that controls the power supply and the load to be turned off or on.

The input peripheral circuit 61 includes a third photo coupler U14, fifty-seventh and fifty-eighth resistors, and a fifty-ninth resistor, the fifty-seventh resistor for current limiting, and the fifty-eighth resistor for protecting the photo coupler. Referring to fig. 9, a partial circuit diagram embodiment of the input peripheral circuit 61 and the output peripheral circuit 62 is given:

the collector of the third photoelectric coupler U14 is connected with a power supply, the emitter of the third photoelectric coupler U14 is connected with the controller U13 (PA 0 port) through a fifty-ninth resistor R59 in series, the emitter of the third photoelectric coupler U14 is grounded through a sixty resistor R60, the positive electrode of the third photoelectric coupler U14 is connected with the high-level end of the load equipment through a fifty-seventh resistor R57, the negative electrode of the third photoelectric coupler U14 is connected with the high-level end of the load equipment, and a fifty-eighth resistor R58 is connected between the positive electrode and the negative electrode of the third photoelectric coupler U14 in parallel.

The output peripheral circuit 62 includes a fourth optocoupler U15, a sixty-first resistor, a sixty-second resistor R62, a seventh diode, a first triode, and a fuse. Referring to fig. 9, a partial circuit embodiment of the output peripheral circuit 62 is shown:

The positive pole of the fourth photoelectric coupler U15 is externally connected with a power supply through a sixty-third resistor R63, the negative pole of the fourth photoelectric coupler U15 is connected with the controller U13 (PA 1 port), the emitter of the fourth photoelectric coupler U15 is connected with the low-level end of the load equipment, and the emitter of the fourth photoelectric coupler U15 is connected with the high-level end of the load equipment through a seventh diode D7.

The base of the first triode Q1 is connected with the collector of the fourth photoelectric coupler U15 through a sixty-second resistor R62, the sixty-second resistor R62 is a current limiting resistor, the base and the emitter of the first triode Q1 are connected through a sixty-first resistor R61, the sixty-first resistor R61 is a pull-up resistor, the emitter of the first triode Q1 is connected with one end of a fuse F1, the other end of the fuse F1 is connected with a power supply, and the collector of the first triode Q1 is connected with the high level end of load equipment.

The drive current of the photoelectric coupler in the isolation protection circuit 7 is small, and the drive current is not enough to be compatible with the large current possibly flowing in the circuit, the circuit part of the first triode Q1 is a drive circuit and used for increasing the drive current and improving the drive capability, the optocoupler controls the triode Q1, the triode Q1 controls the 24-volt power supply to be conducted, the large current flows into the client electric equipment through the 1 pin of PI and flows back into the controller U13 through the 2 pin of PI to form a complete loop, the seventh diode D7 is a protection diode, and the fuse F1 is used for circuit short-circuit protection.

The seventh diode D7 is a small high-speed switching diode of model 1N4148, and the first triode Q1 is a triode of model B772.

In a specific implementation, in the power protection circuit, a plurality of sets of peripheral port circuits 6 (a set of embodiments are shown in fig. 9), a set of dry contacts PO and PI of the peripheral port circuits 6 are correspondingly connected with a high-power switching device, and the high-power switching device is controlled by setting a plurality of dry nodes to assist in switching on and off power equipment or loads. The PO dry node interface is connected with the electric equipment, an input node is used for the controller U13, the PI is connected with the control end or the use end of the electric equipment, and an output node is used for the controller U13.

The electric equipment of the client is unknown, and in order to protect a circuit, the voltage is isolated through the double-channel isolator U9 and the two groups of photoelectric couplers, so that the controller U13 is isolated and protected.

Specifically, the isolation protection circuit 7 includes a dual-channel digital isolator U9, a first optocoupler U11, a second optocoupler U12, a low-power transceiver U10, an electrostatic protector D6, a forty-first resistor, a forty-second resistor, a forty-fourth resistor, a forty-fifth resistor, a forty-seventh resistor, a forty-ninth resistor, a fifty-first resistor, a fifty-second resistor, a fifty-third resistor, a fifty-fourth resistor, a fifty-fifth resistor, a fifty-sixth resistor, and a first switch, the low-power transceiver U10 is connected to a communication circuit through a connector, and the communication circuit is a 485 communication circuit.

A schematic circuit connection diagram of a specific embodiment of the isolation protection circuit 7 is shown in fig. 8.

Specifically, the positive electrode of the first photo coupler U11 is connected to the power supply through the fifty-first resistor R51 connected in series, the negative electrode of the first photo coupler U11 is connected to the controller U13 (PB 8 port), the collector electrode of the first photo coupler U11 is connected to the power supply, the emitter electrode of the first photo coupler U11 is grounded through the fifty-third resistor R53, and the emitter electrode of the first photo coupler U11 is connected to the receiver output enable terminal (re# interface, active low level) of the low power transceiver U10 through the fifty-second resistor R52 connected in series.

The positive pole of the second photo coupler U12 is connected with a power supply through a fifty-fourth resistor R54 in series connection, the negative pole of the second photo coupler U12 is connected with the controller U13 (PB 9 port), the collector of the second photo coupler U12 is connected with the power supply, the emitter of the second photo coupler U12 is grounded through a fifty-sixth resistor R56, and the emitter of the second photo coupler U12 is connected with the driver output enabling end (DE interface, high level and effective) of the low-power-consumption transceiver U10 through a fifty-fifth resistor R55 in series connection.

The first photoelectric coupler U11, the second photoelectric coupler U12, the third photoelectric coupler U14 and the fourth photoelectric coupler U15 are all B light blocking electric couplers with the model number of PC817X2CSP 9F. In this embodiment, the external port circuit 6 realizes nanosecond fast response of the overvoltage phenomenon by arranging a plurality of optocouplers (photodiodes inside).

The two-channel digital isolator U9 is a two-channel digital isolator with the model number of ADUM1201 ARZ. The power supply voltage isolation side pin and the isolator side power supply voltage pin of the double-channel digital isolator U9 are respectively connected with a power supply, a first logic input end of the double-channel digital isolator U9 is connected with an output end (RO port) of the low-power-consumption transceiver U10, a second logic input end of the double-channel digital isolator U9 is connected with the controller U13 (PB 6 port) through a series connection forty-five resistor R45, a first logic output end of the double-channel digital isolator U9 is connected with the controller U13 (PB 6 port) through a series connection forty-two resistor R42, a second logic output end of the double-channel digital isolator U9 is connected with a driver input end (DI port) of the low-power-consumption transceiver U10, and two isolator grounding reference pins of the double-channel digital isolator U9 are grounded.

In detail, one end of the forty-seventh resistor R47, one end of the forty-ninth resistor R49, one end of the first switch SW1 and the second pin end of the electrostatic protector D6 are all connected to the driver output-to-receiver non-inverting input end of the low power consumption transceiver U10, the other end of the forty-seventh resistor R47 is connected to the low level end of the communication circuit, the other end of the forty-ninth resistor R49 is connected to the power supply, and the other end of the first switch SW1 is connected in series with the forty-first resistor R41.

The other end of the forty-first resistor R41, one end of the forty-fourth resistor R44, one end of the fifty-first resistor R50 and the first pin end of the electrostatic protector D6 are all connected to the driver output/receiver inverting input end of the low-power transceiver U10, the other end of the forty-fourth resistor R44 is connected to the high-level end of the communication circuit, the ground pin end of the low-power transceiver U10 and the other end of the fifty-first resistor R50 are grounded, and the third pin end of the electrostatic protector D6 is grounded.

The electrostatic protector D6 is selected from SM712 Transient Voltage Suppressor (TVS).

The above embodiments are only for illustrating the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement the same according to the content of the present invention, and are not intended to limit the scope of the present invention. It will be evident to those skilled in the art that the invention is not limited to the details of the foregoing illustrative embodiments and that the present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof, and it is therefore desired that the present invention be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

Claims

1. A third party detection and fast response power protection circuit comprising: the device comprises a voltage sampling circuit, a current sampling circuit, an analog-to-digital conversion circuit, a voltage comparison circuit, a data processing circuit, an isolation protection circuit and a peripheral port circuit;

2. A third party detection and fast response power supply protection circuit according to claim 1, wherein said data processing circuit comprises a controller U13 and communication circuitry, said peripheral port circuitry comprising input peripheral circuitry and output peripheral circuitry; the power supply device or the load device, the input peripheral circuit, the controller U13 and the output peripheral circuit form a closed loop circuit for controlling the power supply and the load to be turned off.

3. The third party detection and fast response power supply protection circuit according to claim 1, wherein the voltage comparison circuit comprises a voltage comparator U8, a first protection unit and a second protection unit, the voltage comparator U8 having a first input terminal, a second input terminal, a third input terminal, a fourth input terminal, a first output terminal and a second output terminal;

4. A third party detection and fast response power supply protection circuit according to claim 3, wherein said first protection unit comprises a first diode, a second diode, a thirty-fourth resistor and a thirty-fifth resistor;

the third diode and the fourth diode are connected in reverse series, the thirty-seventh resistor is connected in series between the third diode and the negative electrode of the fourth diode, the positive electrode of the fourth diode is connected with a power supply, the positive electrode of the third diode is connected to the data processing circuit through the thirty-sixth resistor, and the first output end of the dual-voltage comparator U8 is connected between the third diode and the thirty-seventh resistor.

5. The third party detection and fast response power protection circuit according to claim 2, wherein the isolation protection circuit comprises a dual-channel digital isolator U9, a first optocoupler U11, a second optocoupler U12, a low power transceiver U10, the low power transceiver U10 being connected to the communication circuit by a connector;

6. The third party detection and fast response power supply protection circuit according to claim 5, wherein said isolation protection circuit further comprises an electrostatic protector, a forty-seventh resistor, a forty-ninth resistor, a forty-first resistor, a forty-fourth resistor, a fifty-first resistor, and a first switch;

7. The third party detection and fast response power supply protection circuit according to claim 2, wherein the input peripheral circuit comprises a third optocoupler U14, a fifty-seventh resistor, a fifty-eighth resistor, and a fifty-ninth resistor, the fifty-seventh resistor being a current limiting resistor, the fifty-eighth resistor being a protection resistor;

the emitter of the third photoelectric coupler U14 is connected with the controller U13 through the fifty-ninth resistor in series, the positive electrode of the third photoelectric coupler U14 is connected to the high-level end of the load equipment through the fifty-seventh resistor, the negative electrode of the third photoelectric coupler U14 is connected to the high-level end of the load equipment, and the fifty-eighth resistor is connected between the positive electrode and the negative electrode of the third photoelectric coupler U14.

8. The third party detection and fast response power supply protection circuit according to claim 2, wherein said output peripheral circuit comprises a fourth optocoupler U15, a sixty-first resistor, a sixty-second resistor, a seventh diode and a first triode;

The base electrode of the first triode is connected with the collector electrode of the fourth photoelectric coupler U15 through a sixty-two resistor in series connection, the base electrode of the first triode is connected with the emitter electrode of the first triode through a sixty-one resistor, and the collector electrode of the first triode is connected with the high level end of the load equipment.

9. The power supply protection circuit for third party detection and quick response according to claim 1, wherein the voltage sampling circuit comprises a first voltage dividing module, an isolation differential module U2 and a first operational amplifier module which are connected in sequence; the first voltage division module is connected between the power supply equipment and the load equipment through a connector U3 and is used for dividing the acquired voltage signals, and the isolation differential module U2 and the first operational amplification module isolate and amplify the voltage signals after voltage drop and output single-ended voltage sampling signals;

the current sampling circuit comprises a Hall sensor, a second voltage dividing module and a voltage follower which are sequentially connected, and the voltage follower carries out equivalent stable output on the divided signals so as to obtain voltage sampling signals of the current sampling circuit;

10. The third party detection and fast response power supply protection circuit according to claim 2, wherein the analog-to-digital conversion circuit comprises an analog-to-digital converter U1 and a voltage reference module connected to the analog-to-digital converter U1, the voltage reference module is provided with a voltage reference for limiting the dynamic range of the sampled voltage, and the first operational amplifier module and the analog-to-digital converter U1 are provided with the same reference ground;