Switching power supply overvoltage protection circuit
By designing voltage detection and control modules in the switching power supply, and using op amp circuits and optocouplers to determine the AC voltage, real-time protection of overvoltage is achieved, and the problem of damage to AC overvoltage in the prior art is solved. It provides a simple structure and fast response speed overvoltage protection solution.
Patent Information
- Application Number
- CN202420952358.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-05-06
- Publication Date
- 2024-12-31
- Estimated Expiration
- 2034-05-06
AI Technical Summary
The problem of damage to electronic equipment due to AC overvoltage in the prior art has not been effectively solved, especially in high-risk environments where effective overvoltage protection measures are lacking.
A switching power supply overvoltage protection circuit including voltage detection module, control module and switching module is designed. By monitoring the AC voltage signal in real time, if the preset threshold is exceeded, a control signal is sent to the switching module to disconnect the circuit to realize overvoltage protection. . The circuit consists of a transformer, rectifier, op amp circuit, optocoupler and thyristor. The overvoltage state is determined by the difference between the same and reverse terminal voltages of the op amp circuit, and the thyristor is triggered through the optocoupler to disconnect the thyristor. Circuit.
It realizes overvoltage protection with simple structure, fast response speed, energy-saving and efficient energy-saving and efficient. It is suitable for various AC power systems, especially in occasions where overvoltage protection is high, effectively preventing equipment damage.
Smart Images
Figure CN222282791U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the technical field of switching power supplies, and in particular relates to an overvoltage protection circuit for a switching power supply. Background Art
[0002] The technology of AC overvoltage protection circuit involves the fields of power system, electronic technology and safety protection. In the power system, whether it is power generation, transmission or distribution, the AC voltage may rise due to various reasons (such as lightning strike, system failure, operating error, etc.), exceeding the normal working range. This phenomenon is called AC overvoltage. Excessive voltage can damage electrical equipment and even endanger personal safety. When designing an AC overvoltage protection circuit, factors that need to be considered include the sensitivity of the protection action, the reliability of the protection equipment, the compatibility and coordination of the system, etc. At the same time, in order to meet the needs of different application scenarios, the AC overvoltage protection circuit also presents the characteristics of diversity and customization. For example, in critical facilities or high-risk environments, higher levels of overvoltage protection measures may be adopted to ensure stable operation of the system and personnel safety.
[0003] In order to prevent the harm caused by AC overvoltage, corresponding protection measures need to be adopted. Traditional AC overvoltage protection methods include the use of lightning arresters, fuses and circuit breakers. These devices can be activated when the voltage is too high to protect other devices in the system by short-circuiting or disconnecting the circuit.
[0004] With the development of electronic technology, modern AC overvoltage protection circuits have introduced more intelligent monitoring and control methods. For example, the use of electronic overvoltage protectors can monitor the grid voltage in real time. When an abnormal voltage increase is detected, the circuit is quickly cut off to avoid damage to the load. In addition, some advanced overvoltage protection circuits also have an automatic reclosing function, which automatically restores power supply after confirming that the overvoltage has been eliminated.
[0005] The Chinese utility model patent with application number 202023259919.2 discloses an amplifier power module for a high-power digital amplifier active speaker system, including a bridge rectifier filter circuit, the input end of the bridge rectifier filter circuit is connected to the AC input, the output end of the bridge rectifier filter circuit is connected to the self-excited half-bridge switching power supply circuit, the input end of the automatic voltage selection circuit is connected to the AC input, and the output end of the automatic voltage selection circuit is connected to the bridge rectifier filter circuit; the output end of the self-excited half-bridge switching power supply circuit is connected to the main power supply bridge rectifier filter voltage stabilization circuit and the auxiliary power supply rectifier filter circuit respectively after the transformer isolates the output circuit. This solution can achieve over-temperature protection, but does not mention overvoltage protection. Utility Model Content
[0006] The purpose of the utility model is to provide a switching power supply overvoltage protection circuit, which overcomes the shortcomings of the prior art and aims to solve the problem that electronic equipment is damaged by AC overvoltage in the prior art. According to the received voltage signal, it is judged whether the AC voltage exceeds a preset protection threshold. If it exceeds the threshold, a control signal is sent to the switch module to disconnect the circuit of the switch module, thereby realizing overvoltage protection.
[0007] To achieve the above purpose, the utility model is implemented through the following technical solutions:
[0008] A switching power supply overvoltage protection circuit comprises a voltage detection module, a control module and a switch module, wherein pins 1 and 2 of a transformer T1 input end are respectively connected to a live wire L and a neutral wire N of a single-phase alternating current power supply AC, pins 3 and 4 of an output end of the transformer T1 are respectively connected to pins 2 and 1 of an input end of a rectifier D1, the positive electrode of pin 3 of the output end of the rectifier D1 is respectively connected to the positive electrode of a polar capacitor C1, one end of a resistor R7, one end of a resistor R10, one end of the resistor R1 and one end of a resistor R11, the negative electrode of pin 4 of the output end of the rectifier D1 is grounded; the negative electrode of the polar capacitor C1 and the other end of the resistor R10 are grounded; the other end of the resistor R1 is connected to the other end of the resistor R11, the negative electrode of a voltage stabilizing diode D2, the positive electrode of the polar capacitor C2, the power supply of an operational amplifier circuit U2 and one end of a resistor R3, the positive electrode of the voltage stabilizing diode D2 and the negative electrode of the polar capacitor C2 are respectively grounded; the other end of the resistor R3 is connected to the positive electrode of the voltage stabilizing diode D2 and the negative electrode of the polar capacitor C2 One end, the other end of the resistor R4 is respectively connected to the same direction end 3 pins of the operational amplifier circuit U2 and one end of the resistor R5, and the other end of the resistor R5 is grounded; the other end of the resistor R7 is respectively connected to one end of the resistor R6, one end of the capacitor C3 and the reverse end 2 pins of the operational amplifier circuit U2, and the other end of the resistor R6 and the other end of the capacitor C3 are respectively grounded; the pin 1 of the operational amplifier circuit U2 is connected to one end of the resistor R8, the pin 4 of the operational amplifier circuit U2 is grounded, the other end of the resistor R8 is connected to the pin 1 of the photoelectric coupler U3, the pin 2 of the photoelectric coupler U3 is grounded, the pin 6 of the photoelectric coupler U3 is connected to one end of the resistor R2, the other end of the resistor R2 is respectively connected to the T1 pole of the thyristor Q2 and the switch output ACL, the pin 4 of the photoelectric coupler U3 is respectively connected to the G pole of the thyristor Q2, one end of the resistor R9 and one end of the capacitor C4, the T2 pole of the thyristor Q2, the other end of the resistor R9 and the other end of the capacitor C4 are connected to the switch output ACOUT.
[0009] Furthermore, the specification of the rectifier D1 is DB106; the specification of the voltage regulator diode D2 is IN4742.
[0010] Furthermore, the specification of the operational amplifier circuit U2 is LM358.
[0011] Furthermore, the specification of the photoelectric coupler U3 is MOC3081.
[0012] Furthermore, the specification of the thyristor Q2 is BTA41-600B.
[0013] Furthermore, the specification of the transformer T1 is EI6X13.
[0014] Furthermore, the resistor R7 is an adjustable resistor.
[0015] Compared with the prior art, the beneficial effects of the utility model are:
[0016] 1) The technical problem of damage to electronic equipment due to AC overvoltage in the prior art is solved, and it is realized that according to the received voltage signal, it is judged whether the AC voltage exceeds the preset protection threshold. When it exceeds the threshold, a control signal is sent to the switch module to make the switch module disconnect the circuit, thereby realizing overvoltage protection.
[0017] 2) The voltage detection module is used to monitor the input AC voltage in real time and transmit the voltage signal to the control module. The control module voltage detection module is used to monitor the input AC voltage in real time and transmit the voltage signal to the control module. The control module determines whether the AC voltage exceeds the preset protection threshold based on the received voltage signal.
[0018] 3) The protection circuit of the utility model has the characteristics of simple structure, fast response speed, energy saving and high efficiency, easy integration, etc. It is suitable for overvoltage protection of various AC power supply systems, especially for occasions with high requirements for overvoltage protection. BRIEF DESCRIPTION OF THE DRAWINGS
[0019] Figure 1 It is a schematic diagram of the structure of an embodiment of the utility model; DETAILED DESCRIPTION
[0020] The technical solution of the present utility model will be clearly and completely described below in conjunction with specific embodiments. Obviously, the described embodiments are only part of the embodiments of the present utility model, rather than all of the embodiments.
[0021] In order to more clearly illustrate the specific implementation methods of the utility model or the technical solutions in the prior art, the specific embodiments required to be used in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the specific embodiments described below are some implementation methods of the utility model. For ordinary technicians in this field, other specific embodiments can be obtained based on these specific embodiments without paying creative work.
[0022] The components of the embodiments of the present invention generally described and shown in the specific embodiments herein can be arranged and designed in countless different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the specific embodiments is not intended to limit the scope of the utility model claimed, but only represents the selected embodiments of the utility model.
[0023] See Figure 1 , is a schematic diagram of the structure of an embodiment of a switching power supply overvoltage protection circuit of the utility model, including a voltage detection module A, a control module B and a switch module C, pins 1 and 2 of the input end of the transformer T1 are respectively connected to the live wire L and the neutral wire N of the single-phase AC power supply AC, pins 3 and 4 of the output end of the transformer T1 are respectively connected to pins 2 and 1 of the input end of the rectifier D1, the positive electrode of pin 3 of the output end of the rectifier D1 is respectively connected to the positive electrode of the polar capacitor C1, one end of the resistor R7, one end of the resistor R10, one end of the resistor R1 and one end of the resistor R11, the negative electrode of pin 4 of the output end of the rectifier D1 is grounded; the negative electrode of the polar capacitor C1 and the other end of the resistor R10 are grounded; the other end of the resistor R1 is connected to the other end of the resistor R11, the negative electrode of the voltage stabilizing diode D2, the positive electrode of the polar capacitor C2, the power supply of the operational amplifier circuit U2, and one end of the resistor R3, the positive electrode of the voltage stabilizing diode D2 and the negative electrode of the polar capacitor C2 are respectively grounded; the The other end is connected to one end of resistor R4, the other end of resistor R4 is respectively connected to pin 3 of the same direction end of operational amplifier circuit U2 and one end of resistor R5, and the other end of resistor R5 is grounded; the other end of resistor R7 is respectively connected to one end of resistor R6, one end of capacitor C3 and pin 2 of the reverse direction end of operational amplifier circuit U2, and the other end of resistor R6 and the other end of capacitor C3 are respectively grounded; pin 1 of operational amplifier circuit U2 is connected to one end of resistor R8, pin 4 of operational amplifier circuit U2 is grounded, the other end of resistor R8 is connected to pin 1 of photoelectric coupler U3, pin 2 of photoelectric coupler U3 is grounded, pin 6 of photoelectric coupler U3 is connected to one end of resistor R2, the other end of resistor R2 is respectively connected to T1 pole of thyristor Q2 and switch output ACL, pin 4 of photoelectric coupler U3 is respectively connected to G pole of thyristor Q2, one end of resistor R9 and one end of capacitor C4, T2 pole of thyristor Q2, the other end of resistor R9 and the other end of capacitor C4 are connected to switch output ACOUT.
[0024] In the embodiment, the specification of the rectifier D1 is DB106; the specification of the voltage regulator diode D2 is IN4742. The specification of the operational amplifier circuit U2 is LM358. The specification of the photocoupler U3 is MOC3081. The specification of the thyristor Q2 is BTA41-600B. The specification of the transformer T1 is EI6X13. The resistor R7 is an adjustable resistor.
[0025] When the utility model embodiment is working, the AC voltage is transformed from AC220V to AC12V through transformer T1 (E16X13), and then the AC is rectified into DC through rectifier D1 (DB106). The polar capacitor C1 (50V100uf) is an energy storage capacitor, which can provide a stable working voltage for the subsequent circuit. Resistor R10 (1K) is a discharge resistor, which quickly discharges capacitor C1 when shutting down. After the rectified DC voltage is limited by the current limiting resistors R1 and R11 (470R), the voltage is stabilized at 12V through the voltage stabilizing diode D2 (1N4742), and the 12V voltage is supplied to the operational amplifier circuit U2 (LM358) through the energy storage capacitor C2 (25V100uf). At the same time, the voltage is divided by resistor R3 / resistor R4 / resistor R5 and enters the same direction end of the operational amplifier circuit U2. The other voltage after rectification is divided by resistor R7 / resistor R6 and enters the reverse end of the operational amplifier. The stable voltage at the same direction end is compared with the voltage at the reverse direction end that changes in real time. By adjusting the resistance value of resistor R7, when the input voltage exceeds AC280V, the voltage at the reverse direction end is higher than that at the same direction end, and the op amp state flips and there is no output. The optocoupler U3 (MOC3081) cannot work, and the thyristor Q2 (BTA41-600B) cannot work without a trigger signal, and the circuit enters the overvoltage protection state. When the input voltage drops to about AC277V, the voltage at the reverse direction end is lower than that at the same direction end, and the op amp circuit U2 flips. The output voltage drives the optocoupler U3 / MOC3081 to work through the current limiting resistor R8 (resistance value 2.4K), and the thyristor Q2 (BTA41-600B) is triggered to turn on, and the overvoltage state is released.
[0026] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.
Claims
1. A switching power supply overvoltage protection circuit, characterized in that: The invention comprises a voltage detection module, a control module and a switch module. Pins 1 and 2 of the input end of the transformer T1 are respectively connected to the live wire L and the neutral wire N of the single-phase AC power supply AC. Pins 3 and 4 of the output end of the transformer T1 are respectively connected to pins 2 and 1 of the input end of the rectifier D1. The positive electrode of pin 3 of the output end of the rectifier D1 is respectively connected to the positive electrode of the polar capacitor C1, one end of the resistor R7, one end of the resistor R10, one end of the resistor R1 and one end of the resistor R11. The negative electrode of pin 4 of the output end of the rectifier D1 is grounded. The negative electrode of the polar capacitor C1 and the other end of the resistor R10 are grounded. The other end of the resistor R1 and the resistor R The other end of 11, the cathode of the voltage zener diode D2, the anode of the polar capacitor C2, the power supply of the operational amplifier circuit U2, and one end of the resistor R3 are connected, and the anode of the voltage zener diode D2 and the cathode of the polar capacitor C2 are grounded respectively; the other end of the resistor R3 is connected to one end of the resistor R4, and the other end of the resistor R4 is respectively connected to the same direction end pin 3 of the operational amplifier circuit U2 and one end of the resistor R5, and the other end of the resistor R5 is grounded; the other end of the resistor R7 is respectively connected to one end of the resistor R6, one end of the capacitor C3 and the reverse end pin 2 of the operational amplifier circuit U2, and the other end of the resistor R6 and the other end of the capacitor C3 are grounded respectively; Pin 1 of the operational amplifier circuit U2 is connected to one end of the resistor R8, pin 4 of the operational amplifier circuit U2 is grounded, the other end of the resistor R8 is connected to pin 1 of the photoelectric coupler U3, pin 2 of the photoelectric coupler U3 is grounded, pin 6 of the photoelectric coupler U3 is connected to one end of the resistor R2, the other end of the resistor R2 is respectively connected to the T1 pole of the thyristor Q2 and the switch output ACL, pin 4 of the photoelectric coupler U3 is respectively connected to the G pole of the thyristor Q2, one end of the resistor R9 and one end of the capacitor C4, the T2 pole of the thyristor Q2, the other end of the resistor R9 and the other end of the capacitor C4 are connected to the switch output ACOUT.
2. A switching power supply overvoltage protection circuit according to claim 1, characterized in that: The specification of the rectifier D1 is DB106; the specification of the voltage regulator diode D2 is IN4742.
3. A switching power supply overvoltage protection circuit according to claim 1, characterized in that: The specification of the operational amplifier circuit U2 is LM358.
4. A switching power supply overvoltage protection circuit according to claim 1, characterized in that: The specification of the photocoupler U3 is MOC3081.
5. The switching power supply overvoltage protection circuit according to claim 1, characterized in that: The specification of the thyristor Q2 is BTA41-600B.
6. A switching power supply overvoltage protection circuit according to claim 1, characterized in that: The specification of the transformer T1 is EI6X13.
7. A switching power supply overvoltage protection circuit according to claim 1, characterized in that: The resistor R7 is an adjustable resistor.