Four-channel AC voltage overcurrent protection circuit

Abstract

The utility model belongs to the technical field of over-current protection modules, and particularly discloses a four-channel alternating current voltage over-current protection circuit, which comprises a current sampling unit used for collecting alternating current, an isolation processing unit used for processing current data and a control unit used for carrying out multi-channel protection control, according to the utility model, through cooperation of the current sampling unit, the isolation processing unit and the control unit, an acquired AC waveform negative half axis can be converted into a synchronous positive axis, the current sampling period is shortened, the real-time performance of current acquisition is ensured, current changes can be responded in time, and rapid execution of protection actions is ensured; the protection circuit is used for preventing overvoltage or overcurrent from damaging the operational circuit, the isolation circuit is used for blocking external interference signals, and the on-off of the switching circuit is controlled, so that a test product is protected, the accuracy of processing acquired current data is improved, and the timeliness and the safety of protecting an electronic product are improved.

Description

Technical Field

[0001] This utility model relates to the technical field of overcurrent protection modules, specifically a four-channel AC voltage overcurrent protection circuit. Background Technology

[0002] In the process of testing electronic products, in order to improve the safety of electronic product testing, AC voltage overcurrent protection modules are usually used to protect the circuits of the test equipment from overcurrent, preventing damage to electronic products caused by overload or short circuit.

[0003] For example, patent application number 201910463792.9 discloses an overcurrent protection circuit module, including a current sampling circuit and an overcurrent protection delay circuit. The current sampling circuit includes a sampling circuit, a reference circuit, and a comparator. The output terminal of the reference circuit is electrically connected to the input terminal of the comparator. The sampling circuit is used to detect the magnitude of the current in the circuit. The comparator compares the sampled value with the reference value, and issues an overcurrent signal when the sampled value is greater than the reference value. The overcurrent protection delay circuit includes an overcurrent protection time setting unit and an overcurrent loop MOSFET control unit, used to control the MOSFET in the overcurrent loop and the protection time. This invention solves the problems of overcurrent and short circuit in power supplies. The circuit is simple, the protection time can be freely set, and there is no need to add auxiliary circuits, thus improving the safety and stability of the power supply circuit.

[0004] However, current overcurrent protection circuit modules are susceptible to external environmental factors, such as increased human intervention, external electromagnetic interference, and external circuit short circuits, which can lead to deviations in the processing of acquired current data, reducing the timeliness and safety of electronic product protection. Therefore, we need to propose a four-channel AC voltage overcurrent protection circuit to solve the above-mentioned problems, thereby improving the accuracy of the processing of acquired current data and enhancing the timeliness and safety of electronic product protection. Utility Model Content

[0005] The purpose of this invention is to provide a four-channel AC voltage overcurrent protection circuit, which can improve the accuracy of processing the acquired current data, and improve the timeliness and safety of protecting electronic products, thereby solving the problems mentioned in the background art.

[0006] To achieve the above objectives, this utility model provides the following technical solution: a four-channel AC voltage overcurrent protection circuit, comprising a current sampling unit for acquiring AC current, an isolation processing unit for processing current data, and a control unit for performing multi-channel protection control. The current sampling unit includes an acquisition circuit for acquiring AC current and an arithmetic circuit for shortening the AC current sampling period. The acquisition circuit and the arithmetic circuit are electrically connected.

[0007] The isolation processing unit includes a protection circuit for protecting the arithmetic circuit and an isolation circuit for isolating external interference signals. The arithmetic circuit is electrically connected to the protection circuit, and the protection circuit is electrically connected to the isolation circuit.

[0008] The control unit includes a voltage regulating circuit for regulating voltage and a switching circuit for controlling the on / off state of multiple channels. The switching circuit is electrically connected to the isolation circuit and the voltage regulating circuit, respectively, and the voltage regulating circuit is electrically connected to the sampling circuit.

[0009] Preferably, the acquisition circuit includes a current transformer L1 for acquiring alternating current, and a resistor R6, a resistor R7, a capacitor C3 and a bidirectional diode D2 are connected in parallel on one side of the current transformer L1.

[0010] Preferably, the arithmetic circuit includes an arithmetic unit U10B, an arithmetic unit U11A, and an arithmetic unit U11B. Pin 5 of the arithmetic unit U10B is connected to one end of a bidirectional diode D2 through a resistor R4. Pin 6 of the arithmetic unit U10B is connected to the other end of the bidirectional diode D2 through a resistor R9. A resistor R10 is connected between pin 6 and pin 7 of the arithmetic unit U10B. The connection between the resistor R10 and the output terminal of the arithmetic unit U10B is connected to pin 3 of the arithmetic unit U11A. Pin 1 of the arithmetic unit U11A is connected to a bidirectional diode D1. Pin 5 of the arithmetic unit U11B is connected to one end of the bidirectional diode D1. A ground resistor R11 is connected to the connection between pin 5 of the arithmetic unit U11B and the bidirectional diode D1. Pin 6 of the arithmetic unit U11B is connected to the other end of the bidirectional diode D1 through a resistor R1. A resistor R2 is connected between pin 6 and pin 7 of the arithmetic unit U11B.

[0011] Preferably, the protection circuit includes an arithmetic unit U32B and an arithmetic unit U32A. Pin 5 of the arithmetic unit U32B is connected to pin 2 of the arithmetic unit U32A via resistors R81 and R80 connected in series. A capacitor C45 is connected to ground at the connection point of the arithmetic unit U32B and resistor R81. A capacitor C46 is connected to ground at the connection point of the arithmetic unit U32B and resistor R80. Pin 7 of the arithmetic unit U32B is connected to resistor R82. One end of resistor R82 is connected to pin 2 of the arithmetic unit U32A. A capacitor C47 is connected to ground. A transistor Q5 is connected to pin 3 of the arithmetic unit U32A. A resistor R66 is connected to the gate of the transistor Q5. A resistor R69 is connected between the gate and drain of the transistor Q5. The source of the transistor Q5 is connected to a resistor R2 through a resistor R64. A capacitor C34 and a resistor R74 are connected to ground at the connection point between the arithmetic unit U32A and the transistor Q5. One end of the resistor R74 is connected to the output terminal of the arithmetic unit U32A through a bidirectional diode D16. One end of the bidirectional diode D16 is connected to a resistor R73 to ground.

[0012] Preferably, the isolation circuit includes coupler U33 and coupler U34. Pin 1 of coupler U33 is connected to the output terminal of arithmetic unit U32A through resistor R83. Pin 1 of coupler U34 is connected to resistor R87. Pins 3 of coupler U34 and pin 3 of coupler U33 are both connected to the switching circuit.

[0013] Preferably, the switching circuit includes relays RLY5 and RLY6 connected to the voltage regulating circuit. A diode D19 and a resistor R78 and a light-emitting diode LED5 are connected in parallel between pins 1 and 2 of relay RLY5. A transistor Q7 is connected to the connection point of diode D19 and LED5. A resistor R88 is connected between the gate and drain of transistor Q7. The gate of transistor Q7 is connected to pin 3 of coupler U33 through resistor R85. A diode D18 and a resistor R79 and LED6 are connected in parallel between pins 1 and 2 of relay RLY6. A transistor Q6 is connected to the connection point of diode D18 and LED6. A resistor R86 is connected between the gate and drain of transistor Q6. The gate of transistor Q6 is connected to pin 3 of coupler U34 through resistor R84.

[0014] Preferably, the voltage regulating circuit includes an external resistor box, one end of which is connected to a capacitor C29, one end of which is connected to a capacitor C28, one end of which passes through a current transformer L1 and is connected to a terminal J12, and relays RLY5 and RLY6 are connected in parallel between capacitors C28 and C29.

[0015] Compared with the prior art, the beneficial effects of this utility model are:

[0016] 1. This utility model, through the cooperation of a current sampling unit, an isolation processing unit, and a control unit, can convert the negative half-axis of the acquired AC waveform to a synchronous positive axis, shorten the current sampling period, ensure the real-time nature of current acquisition, respond promptly to current changes, ensure rapid execution of protection actions, prevent damage to the operational circuit caused by overvoltage or overcurrent through the protection circuit, block external interference signals using the isolation circuit, and control the on / off state of the switching circuit, thereby achieving protection for the tested product, improving the accuracy of the acquired current data processing, and enhancing the timeliness and safety of electronic product protection.

[0017] 2. This utility model, through the cooperation of voltage regulation circuit and switching circuit, can adjust the output voltage as needed, ensuring that electronic products can obtain stable power supply under different working conditions. The switching circuit realizes independent control of different channels, improving the flexibility and accuracy of protection. Attached Figure Description

[0018] Figure 1 This is a circuit block diagram of the present invention;

[0019] Figure 2 This is a circuit diagram of the current sampling unit of this utility model;

[0020] Figure 3 This is a circuit diagram of the isolation processing unit of this utility model;

[0021] Figure 4 This is a circuit diagram of the control unit of this utility model. Detailed Implementation

[0022] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0023] Please see Figure 1-4 This utility model provides a technical solution: a four-channel AC voltage overcurrent protection circuit, including a current sampling unit for collecting AC current, an isolation processing unit for processing current data, and a control unit for multi-channel protection control. The current sampling unit includes a collection circuit for collecting AC current and a calculation circuit for shortening the AC current sampling period. The collection circuit and the calculation circuit are electrically connected.

[0024] The acquisition circuit includes a current transformer L1 for acquiring AC current. On one side of the current transformer L1, resistors R6 and R7, capacitor C3 and bidirectional diode D2 are connected in parallel in sequence. The current transformer L1 acquires AC current and converts the negative half-axis of the AC waveform to the synchronous positive axis, shortening the circuit sampling period to as fast as 50ms, ensuring the real-time performance of current acquisition.

[0025] The arithmetic circuit includes arithmetic unit U10B, arithmetic unit U11A, and arithmetic unit U11B. Pin 5 of arithmetic unit U10B is connected to one end of bidirectional diode D2 through resistor R4. Pin 6 of arithmetic unit U10B is connected to the other end of bidirectional diode D2 through resistor R9. Resistor R10 is connected between pins 6 and 7 of arithmetic unit U10B. The connection between resistor R10 and the output terminal of arithmetic unit U10B is connected to pin 3 of arithmetic unit U11A. Pin 1 of arithmetic unit U11A is connected to bidirectional diode D1. Pin 5 of the arithmetic unit U11B is connected to one end of the bidirectional diode D1, and a ground resistor R11 is connected to the connection point between pin 5 of the arithmetic unit U11B and the bidirectional diode D1. Pin 6 of the arithmetic unit U11B is connected to the other end of the bidirectional diode D1 through resistor R1. A resistor R2 is connected between pins 6 and 7 of the arithmetic unit U11B. By processing the collected current values ​​through arithmetic units U10B, U11A, and U11B, the arithmetic unit can respond to current changes in a timely manner and ensure the rapid execution of protection actions.

[0026] The isolation processing unit includes a protection circuit for protecting the arithmetic circuit and an isolation circuit for isolating external interference signals. The arithmetic circuit is electrically connected to the protection circuit, and the protection circuit is electrically connected to the isolation circuit.

[0027] The protection circuit includes an arithmetic logic unit (ALU) U32B and an ALU U32A. Pin 5 of ALU U32B is connected to pin 2 of ALU U32A via resistors R81 and R80 connected in series. A capacitor C45 is connected to ground at the connection point of ALU U32B and resistor R81. A capacitor C46 is connected to ground at the connection point of resistors R81 and R80. Pin 7 of ALU U32B is connected to resistor R82. One end of resistor R82 is connected to pin 2 of ALU U32A. A capacitor C47 is connected to ground at the connection point of resistor R82 and ALU U32A. Pin 3 of ALU U32A is connected to transistor Q5. The gate of transistor Q5 is connected to resistor R66. A resistor R69 is connected between the gate and drain of transistor Q5. The source of transistor Q5 is connected to resistor R2 through resistor R64. The connection terminal of the arithmetic unit U32A to transistor Q5 is connected to a capacitor C34 to ground and a resistor R74. One end of the resistor R74 is connected to the output terminal of the arithmetic unit U32A through a bidirectional diode D16. One end of the bidirectional diode D16 is connected to a resistor R73 to ground. Through the coordinated operation of arithmetic units U32B and U32A, the detection and calculation of current are realized. Through the control and protection of transistor Q5, the stable operation of the circuit is ensured. Through the function of bidirectional diode D16, the direction of current is controlled and reverse current is protected.

[0028] The isolation circuit includes coupler U33 and coupler U34. Pin 1 of coupler U33 is connected to the output terminal of arithmetic unit U32A through resistor R83. Pin 1 of coupler U34 is connected to resistor R87. Pins 3 of both coupler U34 and coupler U33 are connected to a switching circuit. Coupler U33 and coupler U34 are used to block external interference signals and control the switching circuit, thereby protecting the test product.

[0029] The control unit includes a voltage regulating circuit for regulating voltage and a switching circuit for controlling the on / off state of multiple channels. The switching circuit is electrically connected to the isolation circuit and the voltage regulating circuit, respectively, and the voltage regulating circuit is electrically connected to the sampling circuit.

[0030] The switching circuit includes relays RLY5 and RLY6 connected to the voltage regulation circuit. A diode D19, a resistor R78, and a light-emitting diode LED5 are connected in series between pins 1 and 2 of relay RLY5. A transistor Q7 is connected to the junction of diode D19 and LED5. A resistor R88 is connected between the gate and drain of transistor Q7. The gate of transistor Q7 is connected to pin 3 of coupler U33 via resistor R85. A diode D18, a resistor R79, and a light-emitting diode LED5 are connected in series between pins 1 and 2 of relay RLY6. 6. A transistor Q6 is connected to the connection terminal of diode D18 and LED6. A resistor R86 is connected between the gate and drain of transistor Q6. The gate of transistor Q6 is connected to pin 3 of coupler U34 through resistor R84. Transistor Q7 controls the on / off state of relay RLY5, and transistor Q6 controls the on / off state of relay RLY6. Couplers U33 and U34 are used to transmit signals from the arithmetic unit to transistors Q7 and Q6, while achieving electrical isolation to prevent high voltage or interference signals from affecting subsequent circuits. This enables independent control of different channels, improving the flexibility and accuracy of protection.

[0031] The voltage regulating circuit includes an external resistor box. One end of the external resistor box is connected to a capacitor C29, and one end of the capacitor C29 is connected to a capacitor C28. One end of the capacitor C28 passes through a current transformer L1 and is connected to a terminal J12. Relays RLY5 and RLY6 are connected in parallel between capacitors C28 and C29. The external resistor box adjusts the output voltage by changing its own resistance value, which facilitates adjustment of the output voltage as needed and ensures that the electronic product can obtain a stable power supply under different operating conditions. Capacitors C28 and C29 are connected in parallel with the external resistor box to filter out high-frequency noise in the circuit and ensure the stability of the output voltage.

[0032] By coordinating the current sampling unit, isolation processing unit, and control unit, the negative half-axis of the acquired AC waveform can be converted to the synchronous positive axis, shortening the current sampling period, ensuring the real-time nature of current acquisition, responding promptly to current changes, ensuring rapid execution of protection actions, preventing damage to the operational circuit caused by overvoltage or overcurrent through the protection circuit, blocking external interference signals using the isolation circuit, and controlling the on / off state of the switching circuit, thereby achieving protection of the tested product, improving the accuracy of the acquired current data processing, and enhancing the timeliness and safety of electronic product protection.

[0033] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A four-channel AC voltage overcurrent protection circuit, characterized in that: It includes a current sampling unit for acquiring alternating current, an isolation processing unit for processing current data, and a control unit for performing multi-channel protection control. The current sampling unit includes an acquisition circuit for acquiring alternating current and an arithmetic circuit for shortening the sampling period of alternating current. The acquisition circuit and the arithmetic circuit are electrically connected. The isolation processing unit includes a protection circuit for protecting the arithmetic circuit and an isolation circuit for isolating external interference signals. The arithmetic circuit is electrically connected to the protection circuit, and the protection circuit is electrically connected to the isolation circuit. The control unit includes a voltage regulating circuit for regulating voltage and a switching circuit for controlling the on / off state of multiple channels. The switching circuit is electrically connected to the isolation circuit and the voltage regulating circuit, respectively, and the voltage regulating circuit is electrically connected to the sampling circuit.

2. The four-channel AC voltage overcurrent protection circuit according to claim 1, characterized in that: The acquisition circuit includes a current transformer L1 for acquiring alternating current. A resistor R6, a resistor R7, a capacitor C3, and a bidirectional diode D2 are connected in parallel on one side of the current transformer L1.

3. A four-channel AC voltage overcurrent protection circuit according to claim 2, characterized in that: The arithmetic circuit includes arithmetic unit U10B, arithmetic unit U11A, and arithmetic unit U11B. Pin 5 of arithmetic unit U10B is connected to one end of bidirectional diode D2 through resistor R4. Pin 6 of arithmetic unit U10B is connected to the other end of bidirectional diode D2 through resistor R9. Resistor R10 is connected between pins 6 and 7 of arithmetic unit U10B. The connection between resistor R10 and the output terminal of arithmetic unit U10B is connected to pin 3 of arithmetic unit U11A. Pin 1 of arithmetic unit U11A is connected to bidirectional diode D1. Pin 5 of arithmetic unit U11B is connected to one end of bidirectional diode D1. A ground resistor R11 is connected to the connection between pin 5 of arithmetic unit U11B and bidirectional diode D1. Pin 6 of arithmetic unit U11B is connected to the other end of bidirectional diode D1 through resistor R1. Resistor R2 is connected between pins 6 and 7 of arithmetic unit U11B.

4. A four-channel AC voltage overcurrent protection circuit according to claim 3, characterized in that: The protection circuit includes an arithmetic unit U32B and an arithmetic unit U32A. Pin 5 of the arithmetic unit U32B is connected to pin 2 of the arithmetic unit U32A via resistors R81 and R80 connected in series. A capacitor C45 is connected to ground at the connection point of the arithmetic unit U32B and resistor R81. A capacitor C46 is connected to ground at the connection point of the arithmetic unit U32A and pin 7 of the arithmetic unit U32B is connected to resistor R82. One end of resistor R82 is connected to pin 2 of the arithmetic unit U32A, and the connection point of resistor R82 to the connection point of the arithmetic unit U32A is also connected to... There is a capacitor C47 to ground. A transistor Q5 is connected to pin 3 of the arithmetic unit U32A. A resistor R66 is connected to the gate of the transistor Q5. A resistor R69 is connected between the gate and drain of the transistor Q5. The source of the transistor Q5 is connected to a resistor R2 through a resistor R64. A capacitor C34 and a resistor R74 are connected to ground at the connection point between the arithmetic unit U32A and the transistor Q5. One end of the resistor R74 is connected to the output terminal of the arithmetic unit U32A through a bidirectional diode D16. One end of the bidirectional diode D16 is connected to a resistor R73 to ground.

5. A four-channel AC voltage overcurrent protection circuit according to claim 4, characterized in that: The isolation circuit includes coupler U33 and coupler U34. Pin 1 of coupler U33 is connected to the output terminal of arithmetic unit U32A through resistor R83. Pin 1 of coupler U34 is connected to resistor R87. Pins 3 of coupler U34 and pin 3 of coupler U33 are both connected to the switching circuit.

6. A four-channel AC voltage overcurrent protection circuit according to claim 5, characterized in that: The switching circuit includes relays RLY5 and RLY6 connected to the voltage regulation circuit. A diode D19 and a resistor R78 and a light-emitting diode LED5 are connected in parallel between pins 1 and 2 of relay RLY5. A transistor Q7 is connected to the connection point of diode D19 and LED5. A resistor R88 is connected between the gate and drain of transistor Q7. The gate of transistor Q7 is connected to pin 3 of coupler U33 through resistor R85. A diode D18 and a resistor R79 and LED6 are connected in parallel between pins 1 and 2 of relay RLY6. A transistor Q6 is connected to the connection point of diode D18 and LED6. A resistor R86 is connected between the gate and drain of transistor Q6. The gate of transistor Q6 is connected to pin 3 of coupler U34 through resistor R84.

7. A four-channel AC voltage overcurrent protection circuit according to claim 6, characterized in that: The voltage regulating circuit includes an external resistor box, one end of which is connected to a capacitor C29, and one end of which is connected to a capacitor C28. One end of the capacitor C28 passes through the current transformer L1 and is connected to a terminal J12. The relays RLY5 and RLY6 are connected in parallel between the capacitors C28 and C29.

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