Switching power supply starting control system
By designing auxiliary power circuits and control circuits in the power management system, converting mains AC power into DC voltage and monitoring the output condition, outputting protection control signals to cut off the power supply circuit, solving the problem of voltage and current impact of semiconductor components during power switching process , improves system stability and reliability.
Patent Information
- Application Number
- CN202411602104.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-11
- Publication Date
- 2025-01-14
- Estimated Expiration
- Not applicable · inactive patent
AI Technical Summary
In the case of poor continuous power switch or input lines, semiconductor components are prone to voltage and current peaks, which affects the reliability and efficiency of the system. Traditional solutions increase system costs but do not fundamentally solve the problem.
Design a switching power supply start control system, including auxiliary power circuit, control circuit and main circuit. The auxiliary power circuit converts main power AC into DC voltage, and monitors the output situation in real time through the control circuit, outputs protection control signals to the main circuit, and the main The circuit cuts off the power supply circuit of the electrical equipment to avoid voltage and current impact.
It effectively reduces the voltage and current impact of semiconductor components during power switching, enhances system stability, extends service life, reduces product defect rate, improves the reliability of power management, and realizes high-voltage, low-voltage and overcurrent protection functions.
Smart Images
Figure CN119315495A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of power switch control, and in particular to a switch power supply startup control system. Background Art
[0002] In current power management systems, especially in constant current, constant voltage, and constant voltage constant current power supplies, the soft start function is crucial to improving the stability and safety of the system. However, the existing main control chip is prone to cause semiconductor components to withstand excessive voltage and current peaks under continuous power on and off or poor input lines, affecting the reliability and efficiency of the power system.
[0003] Traditional solutions usually rely on increasing the specifications of power devices or complex circuit designs to alleviate the impact of voltage and current peaks. However, this approach not only increases system costs, but also does not fundamentally solve the problem. Especially during continuous switching, semiconductor components may still suffer from voltage and current shocks, reducing product life and performance stability. Therefore, there is room for improvement. Summary of the invention
[0004] In order to reduce the voltage and current impact of semiconductor components during power switching, enhance system stability and extend service life, reduce product defective rate caused by continuous switching or poor input lines, and improve the reliability of power management, the present application provides a switching power supply startup control system.
[0005] A switch power supply startup control system, comprising an auxiliary power supply circuit, a control circuit and a main circuit; The input end of the auxiliary power supply circuit is coupled to the AC power supply of the mains, and the output end of the auxiliary power supply circuit is coupled to the control circuit and the main circuit respectively. The auxiliary power supply circuit is used to convert the AC power supply of the mains into a DC voltage to provide an operating voltage and a protection threshold voltage of the electronic device; The output end of the control circuit is coupled to the main circuit, and the input end of the control circuit is coupled to the auxiliary power supply circuit to input the protection threshold voltage and the DC voltage. The control circuit is used to monitor the main power conversion output in real time, and output a protection control signal to the main circuit according to the main power conversion output; The input end of the main circuit is coupled to the control circuit to input a protection control signal, and the output end of the main circuit is coupled to the electrical equipment. When the main circuit receives the protection control signal, the power supply circuit electrically connected to the electrical equipment is cut off.
[0006] By adopting the above technical scheme, the auxiliary power supply circuit converts the AC power of the mains into a DC voltage, and then provides a working voltage for the control circuit and the main circuit. At the same time, the auxiliary power supply circuit provides a protection threshold voltage for the control circuit. The control circuit receives the DC voltage converted from the AC power of the mains, and compares the DC voltage with the protection threshold voltage. When the mains is struck by lightning, the DC voltage output from the AC power conversion of the mains changes. The control circuit outputs a protection control signal to the main circuit according to the change in DC voltage. When the main circuit receives the protection control signal, it cuts off the electrical connection loop with the electrical equipment, and cuts off the power to the electrical equipment, thereby timely cutting off the AC power supply circuit, protecting the electrical equipment, and avoiding equipment damage.
[0007] Preferably, the auxiliary power supply circuit includes a rectifier module and a flyback topology module, the input end of the rectifier module is coupled to the AC power supply, the output end of the rectifier module is respectively coupled to the control circuit and the flyback topology module, the rectifier module is used to convert the AC power supply into a DC voltage output, the output end of the flyback topology module is respectively coupled to the control circuit and the main circuit, and the flyback topology module is used to provide an output operating voltage and a protection threshold voltage.
[0008] By adopting the above technical solution, the auxiliary power supply circuit rectifies the input AC power into a DC voltage through the rectifier module and outputs it to the control circuit, so that the control circuit can monitor the AC power supply output DC voltage in real time. The DC voltage output by the rectifier module is adjusted through the flyback topology module to output a power supply voltage that meets the working conditions of the control circuit and the main circuit. At the same time, the protection threshold voltage is output to the control circuit, so that the control circuit can compare the DC voltage with the protection threshold voltage.
[0009] Preferably, the control circuit includes a judgment module and an execution module, the input end of the judgment module is coupled to the auxiliary power supply circuit, the output end of the judgment module is coupled to the execution module, the judgment module is used to compare and judge the DC voltage output by the AC power conversion of the mains with the protection threshold voltage, and output a judgment signal to the execution module based on the comparison and judgment result, the output end of the execution module is coupled to the main circuit, and the execution module is used to output a protection control signal to the main circuit when receiving the judgment signal.
[0010] By adopting the above technical solution, the control circuit compares the DC voltage output by the AC power conversion with the protection threshold voltage through the judgment module. When the DC voltage output by the AC power conversion changes, such as a surge in overcurrent or undervoltage, the judgment module outputs a judgment signal to the execution module based on the comparison result between the DC voltage and the protection threshold voltage. After receiving the judgment signal, the execution module outputs a protection control signal to the main circuit, thereby causing the main circuit to cut off the power supply circuit of the electrical equipment according to the protection control signal.
[0011] Preferably, the main circuit includes a current sensor CT1, a switch relay and a relay driving module, the input end of the current sensor CT1 is coupled to the AC power supply, the output end of the current sensor CT1 is coupled to the judgment module, the current sensor CT1 is used to detect the current output of the AC power supply and transmit it to the judgment module, the input end of the driving module is coupled to the output end of the execution module, the output end of the driving module is coupled to the switch relay, the driving module is used to output a drive signal to the switch relay when receiving a protection control signal, the switch relay is coupled to the power supply circuit of the electrical equipment, and the switch relay is used to control the power supply circuit switch of the electrical equipment.
[0012] By adopting the above technical scheme, when the driving module of the main circuit receives the protection control signal, it outputs the driving signal to the switch relay. When the switch relay receives the driving signal, it promptly cuts off the power supply circuit of the electrical equipment. The current sensor CT1 detects the current output of the AC power supply in real time, and outputs the current of the AC power supply to the judgment module of the control circuit. When the current is too large, the judgment module of the control circuit can promptly output the protection control signal according to the current change, so that the driving module outputs the driving signal to the switch relay, and the switch relay cuts off the power supply circuit of the electrical equipment, thereby protecting the electrical equipment from damage due to excessive current.
[0013] Preferably, the judgment module includes a high-voltage protection submodule, which includes a fifteenth resistor R15, a sixteenth resistor R16, a twentieth resistor R20, a twenty-first resistor R21, a first comparator U2A and an eighth diode D8. The first input end of the first comparator U2A is connected in series with the fourteenth resistor R14 and then coupled to the flyback topology module. The second input end of the first comparator U2A is connected in series with the sixteenth resistor R16 and the fifteenth resistor R15 in sequence and then coupled to the output end of the rectifier module. The connection node of the fifteenth resistor R15 and the sixteenth resistor R16 is coupled to the twenty-first resistor R21, and the other end of the twenty-first resistor R21 is grounded. The output end of the first comparator U2A is coupled to the cathode of the eighth diode D8, the anode of the eighth diode D8 is coupled to the twentieth resistor R20, the other end of the twentieth resistor R20 is coupled to the connection node of the sixteenth resistor R16 and the second input end of the first comparator U2A, and the output end of the first comparator U2A is connected in series with the seventh diode D7 and is also coupled to the execution module.
[0014] By adopting the above technical scheme, the protection threshold voltage is input through the first input terminal of the comparator U2A, and the DC voltage converted by the AC power is input through the second input terminal of the comparator U2A. The comparator U2A compares the DC voltage converted by the AC power with the protection threshold voltage. When the DC voltage converted by the AC power surges, the voltage input to the second input terminal of the comparator U2A is greater than the voltage input to the first input terminal. The output terminal of the comparator U2A outputs a high level, the seventh diode D7 is broken down, and the judgment module outputs a high-voltage signal to the execution module to realize the high-voltage protection function. The eighth diode D8, the twentieth resistor R20 and the sixteenth resistor R16 form a recovery hysteresis loop circuit, so that the comparator U2A constitutes a hysteresis comparator, improves the anti-interference ability, and improves the accuracy of the comparison result between the DC voltage converted by the AC power and the protection threshold voltage.
[0015] Preferably, the judgment module also includes a low-voltage protection submodule, which includes a twenty-third resistor R23, a twenty-fifth resistor R25, a twenty-sixth resistor R26, a twenty-seventh resistor R27, a twenty-eighth resistor R28, a second comparator U2C and a tenth diode D10, a first input end of the second comparator U2C is connected in series with a twenty-fourth resistor R24 and then coupled to the twenty-third resistor R23, the other end of the twenty-third resistor R23 is coupled to the output end of the rectifier module, a second input end of the second comparator U2C is connected in series with a twenty-fifth resistor R25 and then coupled to the flyback topology module, and the twenty-third The connection node of the resistor R23 and the twenty-fourth resistor R24 is coupled to the twenty-sixth resistor R26, both ends of the twenty-sixth resistor R26 are connected in parallel with the twenty-seventh resistor R27, the other end of the twenty-sixth resistor R26 is grounded, the output end of the second comparator U2C is coupled to the cathode of the tenth diode D10, the anode of the tenth diode D10 is coupled to the twenty-eighth resistor R28, the other end of the twenty-eighth resistor R28 is coupled to the connection node of the twenty-fifth resistor R25 and the second input end of the second comparator U2C, and the output end of the second comparator U2C is connected in series with the ninth diode D9 and is also coupled to the execution module.
[0016] By adopting the above technical scheme, the protection threshold voltage is input through the second input terminal of the second comparator U2C, and the DC voltage converted and output by the mains is input through the second input terminal of the second comparator U2C. The second comparator U2C compares the DC voltage converted and output by the mains with the protection threshold voltage. When the DC voltage converted by the mains is too low, an undervoltage or low voltage situation occurs. The voltage input to the first input terminal of the second comparator U2C is less than the voltage input to the second input terminal. The output terminal of the second comparator U2C outputs a high level, the ninth diode D9 is broken down, and the judgment module outputs a low voltage signal to the execution module to realize the low voltage protection function. The tenth diode D10, the twenty-fifth resistor R25 and the twenty-eighth resistor R28 form a recovery hysteresis loop circuit, so that the second comparator U2C constitutes a hysteresis comparator, improves the anti-interference ability of the second comparator U2C, and improves the accuracy of the comparison result between the DC voltage converted and output by the mains and the protection threshold voltage.
[0017] Preferably, the judgment module also includes an overcurrent protection submodule, which includes a twenty-ninth resistor R29, a thirty-first resistor R31, a thirty-second resistor R32, a voltage converter, a third comparator U2D and a fifteenth diode D15, the input end of the voltage converter is coupled to the current sensor CT1, the output end of the voltage converter is connected in series with the twenty-ninth resistor R29 and then coupled to the first input end of the third comparator U2D, the second input end of the third comparator U2D is connected in series with the thirty-first resistor R31 and then coupled to the flyback topology module, the output end of the third comparator U2D is coupled to the cathode of the fifteenth diode D15, the anode of the fifteenth diode D15 is coupled to the thirty-second resistor R32, the other end of the thirty-second resistor R32 is coupled to the connection node between the thirty-first resistor R31 and the second input end of the third comparator U2D, and the output end of the third comparator U2D is connected in series with the thirteenth diode D13 and is also coupled to the execution module.
[0018] By adopting the above technical solution, the protection threshold voltage is input through the second input terminal of the third comparator U2D, the voltage converter converts the current of the AC power supply input by the current sensor CT1 into a voltage and then inputs it through the second input terminal of the third comparator U2D, the third comparator U2D converts the current of the AC power supply into a voltage and compares it with the protection threshold voltage, when the current output by the AC power supply overcurrents, the voltage converted from the current of the AC power supply is too high, the voltage input to the first input terminal of the third comparator U2D is less than the voltage input to the second input terminal, the output terminal of the third comparator U2D outputs a high level, the thirteenth diode D13 is broken down, the judgment module outputs an overcurrent signal to the execution module, and the circuit overcurrent protection function is realized, the fifteenth diode D15, the thirty-first resistor R31 and the thirty-second resistor R32 form a recovery hysteresis loop circuit, so that the third comparator U2D constitutes a hysteresis comparator, improves the anti-interference ability of the third comparator U2D, and improves the accuracy of the comparison result of the current of the AC power supply converted into a voltage and the protection threshold voltage.
[0019] Preferably, the execution module includes a fourth comparator U2B, an eighteenth resistor R18, a nineteenth resistor R19, a twenty-second resistor R22 and a thirteenth capacitor C13, a first input end of the fourth comparator U2B is connected in series with the nineteenth resistor R19 and then coupled to the flyback topology module, a second input end of the fourth comparator U2B is coupled to the twenty-second resistor R22, the other end of the twenty-second resistor R22 is coupled to the eighteenth resistor R18, the other end of the eighteenth resistor R18 is coupled to the flyback topology module, a connection node between the eighteenth resistor R18 and the twenty-second resistor R22 is coupled to the thirteenth capacitor C13, the other end of the thirteenth capacitor C13 is grounded, a connection node between the eighteenth resistor R18 and the thirteenth capacitor C13 is respectively coupled to the anode of the seventh diode D7, the anode of the ninth diode D9 and the anode of the thirteenth diode D13, and an output end of the fourth comparator U2B is coupled to the driving module of the main circuit.
[0020] By adopting the above technical solution, when the execution module receives any one of the high-voltage signal, the low-voltage signal and the overcurrent signal, the second input terminal of the fourth comparator U2B inputs a low level, the voltage input to the second input terminal of the fourth comparator U2B is less than the voltage input to the first input terminal, the output terminal of the fourth comparator U2B outputs a low level, and the execution module outputs a protection control signal to the driving module of the main circuit, thereby controlling the main circuit to cut off the power supply circuit of the electrical equipment, thereby realizing the function of protecting the electrical equipment from damage.
[0021] Preferably, the driving module includes an NPN transistor Q1, a second resistor R2 and a third resistor R3, the base of the transistor Q1 is connected in series with the second resistor R2 and coupled to the output end of the fourth comparator U2B, the connection node between the second resistor R2 and the base of the transistor Q1 is coupled to the third resistor R3, the other end of the third resistor R3 is grounded, the collector of the transistor Q1 is coupled to the switch relay, and the emitter of the transistor Q1 is grounded.
[0022] By adopting the above technical solution, when the driving module receives the protection control signal output by the execution module, the base input of the NPN transistor Q1 is low level, and the transistor Q1 is in a disconnected state, causing the switch relay to be de-energized and tripped to be in a disconnected state, and the power supply circuit of the electrical equipment is disconnected, thereby realizing the function of driving to cut off the power supply circuit of the electrical equipment.
[0023] In summary, the present application includes at least one of the following beneficial technical effects: 1. The auxiliary power supply circuit converts the AC power of the mains into a DC voltage, and then provides the working voltage and the protection threshold voltage to the control circuit and the main circuit. The control circuit receives the DC voltage converted from the AC power of the mains, and compares the DC voltage with the protection threshold voltage. When the mains is struck by lightning, the DC voltage output from the AC power conversion of the mains changes. The control circuit outputs a protection control signal to the main circuit according to the change of the DC voltage. When the main circuit receives the protection control signal, it cuts off the electrical connection loop with the electrical equipment, and the electrical equipment is powered off, so as to timely cut off the mains power supply circuit, protect the electrical equipment, and avoid equipment damage; 2. A flyback topology module is set in the auxiliary power supply circuit to adjust the DC voltage output by the rectifier module to output a power supply voltage that meets the working conditions of the control circuit and the main circuit, and at the same time output a protection threshold voltage to the control circuit, so that the control circuit can compare the DC voltage with the protection threshold voltage; 3. The judgment module of the control circuit is provided with a high-voltage protection submodule, a low-voltage protection submodule and an overcurrent protection submodule. When the execution module receives any one of the high-voltage signal, the low-voltage signal and the overcurrent signal, it outputs a protection control signal to the driving module of the main circuit to control the main circuit to cut off the power supply circuit of the electrical equipment, so that the switch power supply startup control system can have high-voltage protection, low-voltage protection and overcurrent protection functions at the same time. BRIEF DESCRIPTION OF THE DRAWINGS
[0024] Figure 1 It is a circuit structure block diagram of an embodiment of a switching power supply startup control system of the present application.
[0025] Figure 2 It is a circuit diagram of an auxiliary power supply circuit of an embodiment of a switching power supply startup control system of the present application.
[0026] Figure 3It is a circuit diagram of a control circuit of an embodiment of a switching power supply startup control system of the present application.
[0027] Figure 4 It is a circuit diagram of the main circuit of an embodiment of a switching power supply startup control system of the present application.
[0028] Explanation of the accompanying drawings: 1. Auxiliary power supply circuit; 11. Rectification module; 12. Flyback topology module; 2. Control circuit; 21. Judgment module; 211. High-voltage protection submodule; 212. Low-voltage protection submodule; 213. Overcurrent protection submodule; 22. Execution module; 3. Main circuit; 31. Drive module; 32. Switch relay. DETAILED DESCRIPTION
[0029] The following is combined with Figure 1-4 This application is described in further detail.
[0030] Reference Figure 1 A switching power supply startup control system includes an auxiliary power supply circuit 1, a control circuit 2 and a main circuit 3. The auxiliary power supply circuit 1 includes a rectifier module 11 and a flyback topology module 12. The input end of the rectifier module 11 is coupled to the AC power supply of the mains. The input end of the flyback topology module 12 is coupled to the output end of the rectifier module 11. The output end of the flyback topology module 12 is coupled to the control circuit 2. The rectifier module 11 converts the AC power supply of the mains into a DC power supply and outputs it to the flyback topology module 12. The flyback topology module 12 adjusts the input DC voltage and outputs the power supply voltage for the control circuit 2 and the main circuit 3 to work, and outputs the protection threshold voltage to the control circuit 2. The control circuit 2 includes a judgment module 21 and an execution module 22. The input end of the judgment module 21 is coupled to the output end of the rectifier module 11 to input the DC voltage converted and output by the AC power supply. The input end of the judgment module 21 is also coupled to the flyback topology module 12 to input the protection threshold voltage. The output end of the judgment module 21 is coupled to the execution module 22. The judgment module 21 is used to compare and judge the DC voltage converted and output by the AC power supply with the protection threshold voltage, and output a judgment signal to the execution module 22 according to the comparison and judgment result. The output end of the execution module 22 is coupled to the main circuit 3. When the execution module 22 receives the judgment signal, it outputs a protection control signal to the main circuit 3. Specifically, the judgment signal specifically includes a high voltage signal, a low voltage signal and an overcurrent signal.
[0031] The main circuit 3 includes a current sensor CT1, a switch relay 32 and a relay driving module 31. The input end of the current sensor CT1 is coupled to the AC power supply, and the output end of the current sensor CT1 is coupled to the judgment module 21. The current sensor CT1 is used to detect the current output of the AC power supply and transmit it to the judgment module 21, so that the judgment module 21 can make an overcurrent judgment. The input end of the driving module 31 is coupled to the execution module 22, and the output end of the driving module 31 is coupled to the switch relay 32. The switch relay 32 is coupled to the power supply circuit of the electrical equipment. When the driving module 31 receives the protection control signal output by the execution module 22, it outputs a drive signal to the switch relay 32. After receiving the drive signal, the switch relay 32 is in a disconnected state, thereby cutting off the power supply circuit of the electrical equipment.
[0032] Reference Figure 2 The rectifier module 11 includes a first diode D1, a second diode D2, a third diode D3, a fourth diode D4 and a first capacitor C1, the cathode of the first diode D1 is coupled to the cathode of the second diode D2, the anode of the second diode D2 is coupled to the live wire of the AC power supply, the anode of the first diode D1 is coupled to the neutral wire of the AC power supply, the cathode of the third diode D3 is coupled to the anode of the second diode D2, the anode of the third diode D3 is coupled to the anode of the fourth diode D4, and the cathode of the fourth diode D4 is coupled to the anode of the first diode D1 anode, a connection node between the third diode D3 and the fourth diode D4 is grounded, a connection node between the first diode D1 and the second diode D2 is used to output a DC voltage L1, one end of the first capacitor C1 is coupled to the connection node between the first diode D1 and the second diode D2, the other end of the first capacitor C1 is grounded, a connection node between the first diode D1 and the second diode D2 is connected in series with a first resistor R1, the other end of the first resistor R1 is coupled to the flyback topology module 12, and a connection node between the first diode D1 and the second diode D2 is also coupled to the flyback topology module 12.
[0033] The flyback topology module 12 includes a chip U1, a MOS tube Q2 and a transformer TX1. The chip U1 includes eight pins. The seventh pin of the chip U1 is a DC voltage input terminal. The seventh pin of the chip U1 is coupled to the first resistor R1. The eighth pin of the chip U1 is a protection threshold voltage output terminal. The eighth pin of the chip U1 is coupled to the sixth resistor R6. The other end of the sixth resistor R6 is coupled to the tenth capacitor C10. The other end of the tenth capacitor C10 is grounded. The eighth pin of the chip U1 is also coupled to the sixth capacitor C6. The other end of the sixth capacitor C6 is grounded. The connection node between the eighth pin of the chip U1 and the sixth capacitor C6 outputs the protection threshold voltage Vref. The sixth pin of the chip U1 is coupled to a fourth resistor R4, the other end of the fourth resistor R4 is coupled to the G pole of the MOS tube Q2, the D pole of the MOS tube Q2 and the connection node of the first diode D1 and the second diode D2 are coupled to the primary of the transformer TX1, the secondary of the transformer TX1 is coupled to a sixth diode D6, the cathode of the sixth diode D6 is coupled to a fourth capacitor C4, the other end of the fourth capacitor C4 is coupled to the secondary of the transformer TX1, and the connection node of the sixth diode D6 and the fourth capacitor C4 outputs the working voltage VCC. The seventh pin of the chip U1 is coupled to the connection node of the first resistor R1 with a third capacitor C3, the other end of the third capacitor C3 is grounded, the two ends of the third capacitor C3 are connected in parallel with the second capacitor C2, the connection node of the second capacitor C2 and the third capacitor C3 is coupled with a fifth diode D5, and the anode of the fifth diode D5 is coupled to the working voltage VCC.
[0034] The eighth pin of the chip U1 is also coupled to the ninth capacitor C9, the other end of the ninth capacitor C9 is grounded, and the fourth pin of the chip U1 is coupled to the connection node of the sixth resistor R6 and the tenth capacitor C10. The first pin of the chip U1 is coupled to the eleventh resistor R11, the other end of the eleventh resistor R11 is sequentially connected in series with the twelfth resistor R12 and the thirteenth resistor R13, the connection node of the eleventh resistor R11 and the twelfth resistor R12 is coupled to the tenth resistor R10, the other end of the tenth resistor R10 is grounded, and the other end of the thirteenth resistor R13 is coupled to the working voltage VCC, the fifth pin of the chip U1 is grounded, the second pin of the chip U1 is coupled to the eleventh capacitor C11, the connection node of the second pin of the chip U1 and the eleventh capacitor C11 is coupled to the connection node of the eleventh resistor R11 and the twelfth resistor R12, and the eleventh capacitor The other end of C11 is coupled to the first pin of the chip U1, the third pin of the chip U1 is coupled to the eighth capacitor C8, the other end of the eighth capacitor C8 is grounded, the third pin of the chip U1 is also coupled to the eighth resistor R8, the other end of the eighth resistor R8 is coupled to the S pole of the MOS tube Q2, the connection node between the S pole of the MOS tube Q2 and the eighth resistor R8 is coupled to the ninth resistor R9, the other end of the ninth resistor R9 is grounded, the connection node between the S pole of the MOS tube Q2 and the eighth resistor R8 is also coupled to the fifth capacitor C5, the other end of the fifth capacitor C5 is coupled to the fifth resistor R5, the other end of the fifth resistor R5 is coupled to the D pole of the MOS tube Q2.
[0035] Specifically, the flyback topology module 12 supplies the working voltage VCC of the main circuit 3 and the control circuit 2 with the DC voltage output through the secondary of the transformer TX1, receives the working voltage VCC through the seventh pin and the first pin of the chip U1, monitors the output working voltage, adjusts the output value of the working voltage VCC by adjusting the duty cycle of the MOS tube Q2, and outputs the protection threshold voltage to the control module through the eighth pin of the chip U1.
[0036] Reference Figure 3 The judgment module 21 includes a high voltage protection submodule 211 , a low voltage protection submodule 212 and an overcurrent protection submodule 213 .
[0037] The high voltage protection submodule 211 includes a fifteenth resistor R15, a sixteenth resistor R16, a twentieth resistor R20, a twenty-first resistor R21, a first comparator U2A and an eighth diode D8. The first input terminal of the first comparator U2A is an inverting input terminal, and the second input terminal is a non-inverting input terminal. The inverting input terminal of the first comparator U2A is connected in series with a fourteenth resistor R14 and then coupled to the connection node of the eighth pin of the chip U1 and the sixth capacitor C6. The non-inverting input terminal of the first comparator U2A is connected in series with the sixteenth resistor R16 and the fifteenth resistor R15 in sequence and then coupled to the connection node of the first diode D1 and the second diode D2. A connection node is connected to the fifteenth resistor R15 and the sixteenth resistor R16, and a connection node is coupled to the twenty-first resistor R21. The other end of the twenty-first resistor R21 is grounded. The two ends of the twenty-first resistor R21 are connected in parallel with the twelfth capacitor C12. The output end of the first comparator U2A is coupled to the cathode of the eighth diode D8. The anode of the eighth diode D8 is coupled to the twentieth resistor R20. The other end of the twentieth resistor R20 is coupled to the connection node of the sixteenth resistor R16 and the non-inverting input end of the first comparator U2A. The output end of the first comparator U2A is connected in series with the seventh diode D7 and is also coupled to the execution module 22.
[0038] Specifically, the protection threshold voltage Vref is input into the inverting input terminal of the first comparator U2A, and the DC voltage L1 converted from the AC power is input into the non-inverting input terminal of the first comparator U2A. When the DC voltage L1 converted from the AC power surges, the voltage input into the non-inverting input terminal of the first comparator U2A is greater than the voltage input into the first input terminal. The output terminal of the first comparator U2A outputs a high level, the seventh diode D7 is broken down, and the judgment module 21 outputs a high-voltage signal to the execution module 22.
[0039] The low voltage protection submodule 212 includes a twenty-third resistor R23, a twenty-fifth resistor R25, a twenty-sixth resistor R26, a twenty-seventh resistor R27, a twenty-eighth resistor R28, a second comparator U2C and a tenth diode D10, wherein the first input terminal of the second comparator U2C is an inverting input terminal, the second input terminal of the second comparator U2C is a non-inverting input terminal, the inverting input terminal of the second comparator U2C is connected in series with a twenty-fourth resistor R24 and then coupled to the twenty-third resistor R23, the other end of the twenty-third resistor R23 is coupled to the connection node of the first diode D1 and the second diode D2, the non-inverting input terminal of the second comparator U2C is connected in series with a twenty-fifth resistor R25 and then coupled to the core The connection node of the eighth pin of the chip U1 and the sixth capacitor C6, the connection node of the twenty-third resistor R23 and the twenty-fourth resistor R24 are coupled to the twenty-sixth resistor R26, both ends of the twenty-sixth resistor R26 are connected in parallel with the twenty-seventh resistor R27, the other end of the twenty-sixth resistor R26 is grounded, the output end of the second comparator U2C is coupled to the cathode of the tenth diode D10, the anode of the tenth diode D10 is coupled to the twenty-eighth resistor R28, the other end of the twenty-eighth resistor R28 is coupled to the connection node of the twenty-fifth resistor R25 and the non-inverting input end of the second comparator U2C, and the output end of the second comparator U2C is connected in series with the ninth diode D9 and is also coupled to the execution module 22.
[0040] Specifically, the protection threshold voltage Vref is input into the positive phase input terminal of the second comparator U2C, and the DC voltage L1 output by the AC power conversion is input into the inverting input terminal of the second comparator U2C. When the DC voltage converted by the AC power is too low, an undervoltage or low voltage situation occurs. The voltage input into the inverting input terminal of the second comparator U2C is less than the voltage input into the positive phase input terminal. The output terminal of the second comparator U2C outputs a high level, the ninth diode D9 is broken down, and the judgment module 21 outputs a low voltage signal to the execution module 22.
[0041] The overcurrent protection submodule 213 includes a twenty-ninth resistor R29, a thirty-first resistor R31, a thirty-second resistor R32, a voltage converter, a third comparator U2D and a fifteenth diode D15, wherein the first input terminal of the third comparator U2D is an inverting input terminal, and the second input terminal of the third comparator U2D is a non-inverting input terminal, the voltage converter includes an eleventh diode D11, a twelfth diode D2, a fourteenth diode D14, a sixteenth diode D16 and a thirtieth resistor R30, the anode of the eleventh diode D11 is coupled to the cathode of the sixteenth diode D16, the anode of the sixteenth diode D16 is coupled to the anode of the fourteenth diode D14, the cathode of the fourteenth diode D14 is coupled to the anode of the twelfth diode D12, the cathode of the twelfth diode D12 is coupled to the cathode of the eleventh diode D11, and the connection node of the eleventh diode D11 and the sixteenth diode D16 and the connection node of the fourteenth diode D14 and the twelfth diode D12 are respectively coupled The 30th resistor R30 is connected to the output end of the current sensor CT1, one end of the 30th resistor R30 is coupled to the connection node of the 11th diode D11 and the 12th diode D12, and then coupled to the 29th resistor R29. The other end of the 30th resistor R30 is coupled to the connection node of the 16th diode D16 and the 14th diode D14, and then grounded. The other end of the 29th resistor R29 is coupled to the inverting input end of the third comparator U2D. The non-inverting input end of the third comparator U2D is connected in series with the 31st resistor R31, and then coupled to the connection node of the eighth pin of the chip U1 and the sixth capacitor C6. The output end of the third comparator U2D is coupled to the cathode of the 15th diode D15, and the anode of the 15th diode D15 is coupled to the 32nd resistor R32. The other end of the 32nd resistor R32 is coupled to the connection node of the 31st resistor R31 and the non-inverting input end of the third comparator U2D. The output end of the third comparator U2D is connected in series with the 13th diode D13, and is also coupled to the execution module 22.
[0042] Specifically, the protection threshold voltage Vref is input into the non-phase input terminal of the third comparator U2D, and the voltage converter converts the current of the AC power supply input by the current sensor CT1 into a voltage and then inputs it through the inverting input terminal of the third comparator U2D. When the current output by the AC power supply overcurrents, the current converted from the AC power supply is too high, and the voltage across the twenty-ninth resistor R29 becomes smaller. The voltage input to the inverting input terminal of the third comparator U2D is less than the voltage input to the non-phase input terminal. The output terminal of the third comparator U2D outputs a high level, and the thirteenth diode D13 is broken down. The judgment module 21 outputs an overcurrent signal to the execution module 22.
[0043] The execution module 22 includes a fourth comparator U2B, an eighteenth resistor R18, a nineteenth resistor R19, a twenty-second resistor R22 and a thirteenth capacitor C13, wherein the first input terminal of the fourth comparator U2B is an inverting input terminal, the second input terminal of the fourth comparator U2B is a non-inverting input terminal, the inverting input terminal of the fourth comparator U2B is connected in series with the nineteenth resistor R19 and then coupled to the connection node between the eighth pin of the chip U1 and the sixth capacitor C6, the non-inverting input terminal of the fourth comparator U2B is coupled to the twenty-second resistor R22, the twenty-second resistor R19 is connected in series with ... twenty-second resistor R19, the non-inverting input terminal of the fourth comparator U2B is coupled to the twenty-second resistor R22, the twenty-second resistor R19 is connected in series with the twenty-second resistor R19, the non-inverting input terminal of the fourth comparator U2B is coupled to the twenty-second resistor R22, the twenty The other end of R22 is coupled to the eighteenth resistor R18, the other end of the eighteenth resistor R18 is coupled to the working voltage VCC, the connection node of the eighteenth resistor R18 and the twenty-second resistor R22 is coupled to the thirteenth capacitor C13, the other end of the thirteenth capacitor C13 is grounded, the connection node of the eighteenth resistor R18 and the thirteenth capacitor C13 is respectively coupled to the anode of the seventh diode D7, the anode of the ninth diode D9 and the anode of the thirteenth diode D13, and the output end of the fourth comparator U2B is coupled to the driving module 31 of the main circuit 3.
[0044] Specifically, when the execution module 22 receives any one of a high voltage signal, a low voltage signal and an overcurrent signal, a low level is input to the positive input terminal of the fourth comparator U2B, the voltage input to the positive input terminal of the fourth comparator U2B is less than the voltage input to the inverting input terminal, and the output terminal of the fourth comparator U2B outputs a low level.
[0045] Reference Figure 4 The driving module 31 includes an NPN transistor Q1, a second resistor R2, a third resistor R3 and a Zener diode ZD1. The base of the transistor Q1 is connected in series with the second resistor R2 and coupled to the output end of the fourth comparator U2B. The connection node between the second resistor R2 and the base of the transistor Q1 is coupled to the third resistor R3. The other end of the three resistors R3 is grounded. The collector of the transistor Q1 is coupled to the switch relay 32. The emitter of the transistor Q1 is grounded. One end of the Zener diode ZD1 is coupled to the collector of the transistor Q1, and the other end of the Zener diode ZD1 is grounded.
[0046] The switch relay 32 includes a relay RY1 and a relay RY2, and the current sensor CT1 includes four pins. The second pin of the current sensor CT1 is connected in series with the first fuse F1 and then coupled to the live wire of the AC power supply. The fourth pin of the current sensor CT1 is connected in series with the relay RY1 and then coupled to the seventh capacitor. The other end of the seventh capacitor C7 is connected in series with the relay RY2 and the second fuse F2 in sequence and then coupled to the neutral wire of the AC power supply. Both ends of the seventh capacitor C7 are coupled to the electrical equipment. The first pin of the current sensor CT1 is coupled to the connection node of the fourteenth diode D14 and the twelfth diode D12, and the fourth pin of the current sensor CT1 is coupled to the connection node of the eleventh diode D11 and the sixteenth diode D16.
[0047] The implementation principle of a switch power supply startup control system in the embodiment of the present application is as follows: the rectifier module 11 of the auxiliary power supply circuit 1 rectifies the input AC power of the mains into a DC voltage and outputs it to the control circuit 2, so that the control circuit 2 can monitor the DC voltage output by the AC power of the mains in real time; the flyback topology module 12 of the auxiliary power supply circuit 1 adjusts the DC voltage output by the rectifier module 11 to output a supply voltage that satisfies the operation of the control circuit 2 and the main circuit 3, and outputs a protection threshold voltage to the control circuit 2, so that the control circuit 2 can compare the DC voltage with the protection threshold voltage; When the DC voltage L1 converted from the mains surges, the protection threshold voltage Vref is input to the inverting input of the first comparator U2A of the high-voltage protection submodule 211 of the control circuit 2, the DC voltage L1 converted from the mains is input to the non-inverting input of the first comparator U2A, the voltage input to the non-inverting input of the first comparator U2A is greater than the voltage input to the first input, the output of the first comparator U2A outputs a high level, the seventh diode D7 is broken down, the judgment module 21 outputs a high-voltage signal to the execution module 22, the execution module 22 receives the high-voltage signal, the non-inverting input of the fourth comparator U2B inputs a low level, the voltage input to the non-inverting input of the fourth comparator U2B is less than the voltage input to the inverting input, the output of the fourth comparator U2B outputs a low level, the base of the NPN transistor Q1 of the driving module 31 of the main circuit 3 inputs a low level, the transistor Q1 is in a disconnected state, so that the relays RY1 and RY2 of the switch relay 32 are powered off and tripped to be in a disconnected state, the power supply circuit of the electrical equipment is disconnected, and the overvoltage protection function is realized; When the DC voltage converted by the mains is too low, an undervoltage or low voltage situation occurs. The protection threshold voltage Vref is input to the positive input terminal of the second comparator U2C of the judgment module 21, and the DC voltage L1 output by the mains conversion is input to the inverting input terminal of the second comparator U2C. The voltage input to the inverting input terminal of the second comparator U2C is less than the voltage input to the positive input terminal. The output terminal of the second comparator U2C outputs a high level, and the ninth diode D9 is broken down. The judgment module 21 outputs a low voltage signal to the execution module 22. The execution module 22 receives the low voltage signal. The positive input terminal of the fourth comparator U2B inputs a low level. The voltage input to the positive input terminal of the fourth comparator U2B is less than the voltage input to the inverting input terminal. The output terminal of the fourth comparator U2B outputs a low level. The base of the NPN transistor Q1 of the driving module 31 of the main circuit 3 inputs a low level, and the transistor Q1 is in a disconnected state, so that the relays RY1 and RY2 of the switch relay 32 are powered off and tripped to be in a disconnected state, and the power supply circuit of the electrical equipment is disconnected to achieve the low voltage protection function. The current sensor CT1 in the main circuit 3 outputs the current of the AC power supply to the voltage converter of the overcurrent protection submodule 213. The voltage converter converts the current of the AC power supply input by the current sensor CT1 into a voltage and then inputs it through the inverting input terminal of the third comparator U2D. When the current output by the AC power supply overcurrents, the current converted into a voltage of the AC power supply is too high, and the voltage across the twenty-ninth resistor R29 becomes smaller. The voltage input to the inverting input terminal of the third comparator U2D is less than the voltage input to the non-inverting input terminal. The output terminal of the third comparator U2D outputs a high level, and the thirteenth diode D1 3 is broken down, the judgment module 21 outputs an overcurrent signal to the execution module 22, the execution module 22 receives the overcurrent signal, the non-phase input terminal of the fourth comparator U2B inputs a low level, the voltage input to the non-phase input terminal of the fourth comparator U2B is less than the voltage input to the inverting input terminal, the output terminal of the fourth comparator U2B outputs a low level, the base of the NPN transistor Q1 of the driving module 31 of the main circuit 3 inputs a low level, the transistor Q1 is in a disconnected state, so that the relays RY1 and RY2 of the switch relay 32 are powered off and tripped to be in a disconnected state, the power supply circuit of the electrical equipment is disconnected, and the overcurrent protection function is realized.
[0048] The embodiments described above are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, a person skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.
Claims
1. A switching power supply startup control system, characterized in that: It comprises an auxiliary power supply circuit (1), a control circuit (2) and a main circuit (3); The input end of the auxiliary power circuit (1) is coupled to a mains AC power source, the output end of the auxiliary power circuit (1) is coupled to a control circuit (2) and a main circuit (3) respectively, and the auxiliary power circuit (1) is used to convert the mains AC power source into a DC voltage to provide an operating voltage and a protection threshold voltage for the electronic device; The output end of the control circuit (2) is coupled to the main circuit (3), and the input end of the control circuit (2) is coupled to the auxiliary power supply circuit (1) to input a protection threshold voltage and a DC voltage. The control circuit (2) is used to monitor the mains power conversion output in real time and output a protection control signal to the main circuit (3) according to the mains power conversion output. The input end of the main circuit (3) is coupled to the control circuit (2) to input a protection control signal, and the output end of the main circuit (3) is coupled to an electrical device. When the main circuit (3) receives the protection control signal, it cuts off the power supply circuit electrically connected to the electrical device.
2. The switching power supply startup control system according to claim 1, characterized in that: The auxiliary power supply circuit (1) comprises a rectifier module (11) and a flyback topology module (12); the input end of the rectifier module (11) is coupled to a mains AC power supply; the output end of the rectifier module (11) is respectively coupled to a control circuit (2) and the flyback topology module (12); the rectifier module (11) is used to convert the mains AC power supply into a DC voltage output; the output end of the flyback topology module (12) is respectively coupled to a control circuit (2) and a main circuit (3); and the flyback topology module (12) is used to provide an output operating voltage and a protection threshold voltage.
3. The switching power supply startup control system according to claim 2, characterized in that: The control circuit (2) comprises a judgment module (21) and an execution module (22); the input end of the judgment module (21) is coupled to the auxiliary power supply circuit (1); the output end of the judgment module (21) is coupled to the execution module (22); the judgment module (21) is used to compare and judge the DC voltage output by the AC power conversion of the mains with the protection threshold voltage, and output a judgment signal to the execution module (22) according to the comparison result; the output end of the execution module (22) is coupled to the main circuit (3); the execution module (22) is used to output a protection control signal to the main circuit (3) when receiving the judgment signal.
4. The switching power supply startup control system according to claim 3, characterized in that: The main circuit (3) comprises a current sensor CT1, a switch relay (32) and a relay drive module (31); the input end of the current sensor CT1 is coupled to a mains AC power supply; the output end of the current sensor CT1 is coupled to a judgment module (21); the current sensor CT1 is used to detect the current output of the mains AC power supply and transmit the current to the judgment module (21); the input end of the drive module (31) is coupled to the output end of the execution module (22); the output end of the drive module (31) is coupled to the switch relay (32); the drive module (31) is used to output a drive signal to the switch relay (32) when receiving a protection control signal; the switch relay (32) is coupled to a power supply circuit of an electrical device; the switch relay (32) is used to control the power supply circuit switch of the electrical device.
5. The switching power supply startup control system according to claim 4, characterized in that: The judgment module (21) comprises a high-voltage protection submodule (211), the high-voltage protection submodule (211) comprising a fifteenth resistor R15, a sixteenth resistor R16, a twentieth resistor R20, a twenty-first resistor R21, a first comparator U2A and an eighth diode D8, the first input end of the first comparator U2A being connected in series with the fourteenth resistor R14 and then coupled to the flyback topology module (12), the second input end of the first comparator U2A being connected in series with the sixteenth resistor R16 and the fifteenth resistor R15 in sequence and then coupled to the output end of the rectifier module (11). , the connection node of the fifteenth resistor R15 and the sixteenth resistor R16 is coupled to the twenty-first resistor R21, the other end of the twenty-first resistor R21 is grounded, the output end of the first comparator U2A is coupled to the cathode of the eighth diode D8, the anode of the eighth diode D8 is coupled to the twentieth resistor R20, the other end of the twentieth resistor R20 is coupled to the connection node of the sixteenth resistor R16 and the second input end of the first comparator U2A, the output end of the first comparator U2A is connected in series with the seventh diode D7 and is also coupled to the execution module (22).
6. The switching power supply startup control system according to claim 5, characterized in that: The judgment module (21) further comprises a low voltage protection submodule (212), wherein the low voltage protection submodule (212) comprises a twenty-third resistor R23, a twenty-fifth resistor R25, a twenty-sixth resistor R26, a twenty-seventh resistor R27, a twenty-eighth resistor R28, a second comparator U2C and a tenth diode D10, wherein a first input end of the second comparator U2C is connected in series with a twenty-fourth resistor R24 and then coupled to the twenty-third resistor R23, the other end of the twenty-third resistor R23 is coupled to the output end of the rectifier module (11), and a second input end of the second comparator U2C is connected in series with a twenty-fifth resistor R25 and then coupled to the flyback topology module (12). , a connection node between the twenty-third resistor R23 and the twenty-fourth resistor R24 is coupled to the twenty-sixth resistor R26, both ends of the twenty-sixth resistor R26 are connected in parallel with the twenty-seventh resistor R27, the other end of the twenty-sixth resistor R26 is grounded, the output end of the second comparator U2C is coupled to the cathode of the tenth diode D10, the anode of the tenth diode D10 is coupled to the twenty-eighth resistor R28, the other end of the twenty-eighth resistor R28 is coupled to a connection node between the twenty-fifth resistor R25 and the second input end of the second comparator U2C, the output end of the second comparator U2C is connected in series with the ninth diode D9 and is also coupled to the execution module (22).
7. The switching power supply startup control system according to claim 6, characterized in that: The judgment module (21) further comprises an overcurrent protection submodule (213), the overcurrent protection submodule (213) comprising a twenty-ninth resistor R29, a thirty-first resistor R31, a thirty-second resistor R32, a voltage converter, a third comparator U2D and a fifteenth diode D15, the input end of the voltage converter being coupled to the current sensor CT1, the output end of the voltage converter being connected in series with the twenty-ninth resistor R29 and then being coupled to the first input end of the third comparator U2D, the second input end of the third comparator U2D being connected in series with the thirty-first resistor R31 and then being coupled to the flyback topology module (12), the output end of the third comparator U2D being coupled to the cathode of the fifteenth diode D15, the anode of the fifteenth diode D15 being coupled to the thirty-second resistor R32, the other end of the thirty-second resistor R32 being coupled to the connection node between the thirty-first resistor R31 and the second input end of the third comparator U2D, and the output end of the third comparator U2D being connected in series with the thirteenth diode D13 and then being coupled to the execution module (22).
8. The switching power supply startup control system according to any one of claim 7, characterized in that: The execution module (22) comprises a fourth comparator U2B, an eighteenth resistor R18, a nineteenth resistor R19, a twenty-second resistor R22 and a thirteenth capacitor C13. The first input terminal of the fourth comparator U2B is connected in series with the nineteenth resistor R19 and then coupled to the flyback topology module (12). The second input terminal of the fourth comparator U2B is coupled to the twenty-second resistor R22. The other end of the twenty-second resistor R22 is coupled to the eighteenth resistor R18. The other end of the eighteenth resistor R18 is coupled to the flyback topology module (12). The connection node between the eighteenth resistor R18 and the twenty-second resistor R22 is coupled to the thirteenth capacitor C13. The other end of the thirteenth capacitor C13 is grounded. The connection node between the eighteenth resistor R18 and the thirteenth capacitor C13 is respectively coupled to the anode of the seventh diode D7, the anode of the ninth diode D9 and the anode of the thirteenth diode D13. The output terminal of the fourth comparator U2B is coupled to the driving module (31) of the main circuit (3).
9. The switching power supply startup control system according to claim 8, characterized in that: The driving module (31) comprises an NPN transistor Q1, a second resistor R2 and a third resistor R3; the base of the transistor Q1 is connected in series with the second resistor R2 and then coupled to the output end of the fourth comparator U2B; the connection node between the second resistor R2 and the base of the transistor Q1 is coupled to the third resistor R3; the other end of the third resistor R3 is grounded; the collector of the transistor Q1 is coupled to the switch relay (32); and the emitter of the transistor Q1 is grounded.