Feedback regulation self-adaptive switching power supply

Abstract

The utility model discloses a feedback regulation self-adaptive switching power supply, and relates to the field of electronic circuits. Comprising an input module, a lightning protection temperature control module, a rectification filtering module, a voltage transformation module, a control module, a feedback module and an output module. The input module receives alternating current and is connected to the lightning protection temperature control module, and the lightning protection temperature control module suppresses surge voltage and current through a piezoresistor VR1, a fuse F1 and a temperature sensitive resistor NTC1 to guarantee circuit safety. The rectification filtering module converts alternating current into direct current and transmits the direct current to the output module through the voltage transformation module. The control module drives the MOS tube Q1 through the control chip U3, the output voltage is monitored in real time in combination with an optocoupler U5 and a voltage stabilizer U4 in the feedback module, the duty ratio of a switching signal is dynamically adjusted, and self-adaptive stability of the output voltage is achieved. The circuit integrates a filtering protection module and a peak current absorption circuit, filters interference and protects a post-stage circuit, and remarkably improves the stability and safety of a power supply through a feedback regulation mechanism.

Description

Technical Field

[0001] This utility model relates to an electronic circuit, and more particularly to a feedback-regulated adaptive switching power supply. Background Technology

[0002] Switching power supplies, as core power supply components for electronic devices, are widely used in communications, consumer electronics, industrial control, and other fields. Their performance stability directly affects the operational reliability of terminal equipment. Traditional switching power supplies are prone to problems such as unstable output voltage and excessive ripple noise when faced with mains voltage fluctuations, load changes, or external electromagnetic interference, which may lead to equipment failure or shortened lifespan in severe cases.

[0003] In existing technologies, the feedback regulation mechanism of switching power supplies typically employs a simple voltage sampling and duty cycle adjustment strategy, resulting in slow response speed and limited regulation accuracy, making it difficult to achieve fast and stable output under complex operating conditions. Furthermore, the filter circuit design on the input side of traditional power supplies is often inadequate, failing to guarantee the safety and stability of subsequent circuits, leading to significant susceptibility of these circuits to electromagnetic interference. Utility Model Content

[0004] The technical problem to be solved by this utility model is to provide a safer and more stable switching power supply.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by this utility model is as follows:

[0006] A feedback-regulated adaptive switching power supply, the key technologies of which include an input module, a surge protection and temperature control module, a rectifier and filter module, a transformer module, a control module, a feedback module, and an output module;

[0007] The input module includes an L terminal and an N terminal; the L terminal serves as the live wire input terminal, and the N terminal serves as the neutral wire input terminal; the L terminal is connected to the first input terminal of the surge protection temperature control module; the N terminal is connected to the second input terminal of the surge protection temperature control module; the first output terminal of the surge protection temperature control module is connected to the first input terminal of the rectifier and filter module; the second output terminal of the surge protection temperature control module is connected to the second input terminal of the rectifier and filter module; the output terminal of the rectifier and filter module is connected to the first input terminal of the transformer module and the control module respectively; the output terminal of the control module is connected to the second input terminal of the transformer module.

[0008] The first output terminal of the transformer module is connected to the first input terminal of the output module; the second output terminal of the transformer module is connected to the second input terminal of the output module.

[0009] Preferably, the surge protection temperature control module includes a varistor VR1, a fuse F1, and a thermistor NTC1; the L terminal is connected to one end of F1 and the other end is connected to NTC1, the other end of NTC1 is connected to VR1 and serves as the first output terminal of the surge protection temperature control module; the N terminal is connected to the other end of VR1 and serves as the second output terminal of the surge protection temperature control module.

[0010] Preferably, a resistor and a capacitor CX1 are connected in parallel between the first input terminal and the first output terminal of the rectifier and filter module, and then connected to the 2-port and 1-port of the rectifier bridge BD1 respectively. After rectification by the rectifier bridge, a common-mode inductor LF1 and a filter capacitor EC1 are connected in parallel, and the positive terminal of EC1 is used as the output terminal.

[0011] Preferably, the control module includes a control chip U3, wherein the VDD terminal of U3 is connected to capacitor C6, EC5, resistors R22 and R27 respectively; the other end of R27 is connected to the output terminal of the rectifier filter module through R21; the other end of R22 is connected to the cathode of diode D3, and the anode of D3 is connected to port 1 of the inductor and resistor R33 respectively; the other end of R33 is connected to the SE1 terminal of U3 and R30 respectively, and the other end of R30 is grounded; the other end of C5, the cathode of EC5, and port 2 of the inductor are grounded; the GND terminal of U3 is grounded; the FB pin of U3 is connected to resistor R18; the other end of R18 is connected to an optocoupler. The transistor U1 is connected to the collector and capacitor C9; the emitter of U1 and the other end of C9 are grounded; the CS terminal of U3 is connected to capacitor C10 and resistor R1 respectively; the other end of C10 is grounded; the other end of R1 is connected to the drain of MOSFET Q1 and grounded after passing through a protection resistor; R2 is connected in parallel between the gate and drain of Q1; the gate of Q1 is connected to diode D1 and resistor R3 respectively; the other ends of D1 and R3 are connected to the GATE terminal of U3; the drain of Q1 is grounded by resistor R7; capacitor C4 is connected in parallel between the drain and source of Q1; the source of Q1 is connected to the second input terminal of the transformer module as the output terminal of the control module.

[0012] Preferably, the transformer module includes a transformer T1; the output module includes a feedback module and a filter protection module.

[0013] The input terminal of the feedback module is connected to the first output terminal of the transformer module; the output terminal includes a positive voltage output terminal V+ and a negative voltage output terminal V-; the first input terminal of the rectifier-filter module is connected to port 3 of transformer T1 through a spike current absorption circuit; the first output terminal of the transformer module is rectified and then connected in parallel with the second output terminal of the transformer module to a filter protection module and a feedback module, and is connected to the positive voltage output terminal V+ and the negative voltage output terminal V- respectively through a common-mode inductor; the filter protection module includes a filter capacitor, a filter resistor, a bidirectional breakdown diode and a common-mode inductor;

[0014] The feedback module includes an LED U5 and a voltage regulator U4 in the optocoupler; the input signal is connected to the negative terminal of the voltage regulator through U5 and to the reference terminal of U4 through a resistor, and the positive terminal of U4 is grounded.

[0015] The beneficial effects of adopting the above technical solution are as follows:

[0016] In this invention, the feedback module combines a voltage regulator and an optocoupler to form a real-time monitoring feedback system. This system can capture fluctuations in the output voltage and feed them back to the control module to adjust the duty cycle on the input side of the transformer. Ultimately, this achieves negative feedback regulation of the output voltage. This feedback regulation mechanism ensures that the output voltage can be quickly and stably maintained near the rated output value, greatly improving the stability of the power supply.

[0017] This invention incorporates a rectifier and filter module and a peak current absorption module to filter out interference in the circuit and reduce the damage of peak current to the circuit, thereby improving the safety and stability of the power supply. Attached Figure Description

[0018] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0019] Figure 1 This is a circuit diagram of a feedback-regulated adaptive switching power supply proposed in this utility model. Detailed Implementation

[0020] To make the above-mentioned objectives, features, and advantages of this utility model more apparent and understandable, the technical solutions of this utility model will be clearly and completely described below with reference to the accompanying drawings and specific embodiments. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0021] like Figure 1A feedback-regulated adaptive switching power supply includes an input module, a surge protection and temperature control module, a rectifier and filter module, a transformer module, a control module, a feedback module, and an output module.

[0022] The input module includes an L terminal and an N terminal; the L terminal serves as the live wire input, and the N terminal serves as the neutral wire input, responsible for receiving external AC power. The L terminal is connected to the first input terminal of the surge protection temperature control module; the N terminal is connected to the second input terminal of the surge protection temperature control module.

[0023] The surge protection temperature control module includes a varistor VR1, a fuse F1, and a thermistor NTC1. The L terminal is connected to one end of F1 and the other end to NTC1. The other end of NTC1 is connected to VR1 and serves as the first output terminal of the surge protection temperature control module. The N terminal is connected to the other end of VR1 and serves as the second output terminal of the surge protection temperature control module. When AC power is input, the thermistor NTC1, a negative temperature coefficient thermistor, is connected in series in the input circuit to suppress inrush current. The fuse F1 prevents excessive current from damaging the circuit. Simultaneously, the varistor VR1, connected in series, also suppresses surge voltage to protect downstream circuits. The surge protection temperature control module ensures the stability and safety of the entire circuit. The first output terminal of the surge protection temperature control module is connected to the first input terminal of the rectifier and filter module; the second output terminal of the surge protection temperature control module is connected to the second input terminal of the rectifier and filter module.

[0024] A resistor and capacitor CX1 are connected in parallel between the first input and first output terminals of the rectifier and filter module, and then connected to ports 2 and 1 of the rectifier bridge BD1, respectively. After rectification by the rectifier bridge, a common-mode inductor LF1 and a filter capacitor EC1 are connected in parallel, with the positive terminal of EC1 serving as the output terminal. First, the parallel CX1 filters out high-frequency interference in the input current. Then, the rectifier bridge converts the AC current into pulsating DC current. The common-mode inductor and EC1 further filter out AC ripple, resulting in a constant voltage DC current. The rectifier and filter module converts the input AC current into DC current, facilitating subsequent voltage conversion. The output terminal of the rectifier and filter module is connected to the first input terminal of the transformer module and the control module, respectively.

[0025] The control module includes a control chip U3. The VDD terminal of U3 is connected to capacitor C6, EC5, resistors R22 and R27. The other end of R27 is connected to the output of the rectifier / filter module via R21. The other end of R22 is connected to the cathode of diode D3, and the anode of D3 is connected to port 1 of the inductor and resistor R33. The other end of R33 is connected to the SE1 terminal of U3 and resistor R30, with the other end of R30 grounded. The other end of C5, the cathode of EC5, and port 2 of the inductor are grounded. The GND terminal of U3 is grounded. The FB pin of U3 is connected to resistor R18. The other end of R18 is connected to an optocoupler. The collector of transistor U1 is connected to capacitor C9; the emitter of U1 and the other end of C9 are grounded; the CS terminal of U3 is connected to capacitor C10 and resistor R1 respectively; the other end of C10 is grounded; the other end of R1 is connected to the drain of MOSFET Q1 and grounded after passing through a protection resistor; R2 is connected in parallel between the gate and drain of Q1; the gate of Q1 is connected to diode D1 and resistor R3 respectively; the other ends of D1 and R3 are connected to the GATE terminal of U3; the drain of Q1 is grounded by resistor R7; capacitor C4 is connected in parallel between the drain and source of Q1; the source of Q1 serves as the output terminal of the control module and is connected to the second input terminal of the transformer module. The output terminal of the control module is connected to the second input terminal of the transformer module.

[0026] The control module includes a startup circuit, a feedback circuit, an overcurrent detection circuit, and an output circuit. The startup circuit receives current at the input of the control module, charging capacitor EC5. Once the voltage reaches a certain value, exceeding the voltage threshold at VDD, U3 starts, and the GATE pin generates a square wave signal. The output circuit connects the GATE pin to the MOSFET Q1. The square wave at the GATE pin controls the on / off state of Q1, causing the current in the input coil of transformer T1 in the transformer module to switch. The CS pin collects the voltage of R2, which is the voltage between the gate and drain of Q1, indirectly detecting the drain current of Q1. When the current is too high, the CS pin activates its protection mechanism, forming an overcurrent detection circuit. The feedback circuit adjusts the voltage of the FB pin based on the conduction status of U1. It adjusts the FB pin voltage in real time based on information from the feedback module in the output module, thereby adjusting the duty cycle of the square wave output at the GATE pin, thus changing the conduction time and frequency of Q1, and consequently altering the energy storage in the input coil of the transformer in the transformer module.

[0027] The transformer module includes transformer T1; the output module includes a feedback module and a filter protection module; a peak current absorption module is connected in parallel before the first output terminal of the transformer module, and the core absorption component is capacitor C8. During the switching process of the transformer, the energy release in the coil will cause a peak in the constant voltage. At this time, the peak current is absorbed by charging C8.

[0028] The input terminal of the feedback module is connected to the first output terminal of the transformer module; the output terminal includes a positive voltage output terminal V+ and a negative voltage output terminal V-; the first input terminal of the rectifier and filter module is connected to port 3 of transformer T1 through a spike current absorption circuit; the first output terminal of the transformer module is rectified and then connected in parallel with the second output terminal of the transformer module to a filter protection module and a feedback module, which are connected to the positive voltage output terminal V+ and the negative voltage output terminal V- respectively through a common-mode inductor; the filter protection module includes a filter capacitor, a filter resistor, a bidirectional breakdown diode and a common-mode inductor; the filter protection module receives the DC power after rectification by the rectifier diode, filters it through the filter capacitor and resistor, and simultaneously connects the bidirectional breakdown diode in parallel for overcurrent protection; finally, common-mode interference is filtered out by the common-mode inductor before the output.

[0029] The feedback module includes an LED U5 in the optocoupler and a voltage regulator U4. The input signal is connected to the negative terminal of the voltage regulator through U5 and to the reference terminal of U4 through a resistor. The positive terminal of U4 is grounded. The feedback module obtains the output voltage by charging the EC2 capacitor. The output voltage enters the feedback module and controls the internal resistance of the voltage regulator U4. When the output voltage does not match the standard voltage, the brightness of U5 changes, causing a change in the current at U1, which in turn changes the voltage at the FB pin, ultimately changing the duty cycle of the signal generated by the GATE pin, thereby changing the input voltage of the transformer module. In specific implementation, when the output voltage is less than the standard voltage, the voltage at the reference terminal of U4 decreases, the internal resistance of U4 increases, the current flowing through U5 decreases, the brightness of the LED weakens, the conduction degree of U1 decreases, the voltage at FB changes, the duty cycle of the output signal at the GATE pin increases, the energy stored on the input side of the transformer T1 increases, driving the voltage of subsequent circuits to rise, and vice versa. This achieves voltage feedback regulation, ultimately achieving a stable output of rated DC voltage.

[0030] The above description of the disclosed embodiments enables those skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A feedback-regulated adaptive switching power supply, characterized in that, It includes an input module, a surge protection and temperature control module, a rectification and filtering module, a transformer module, a control module, a feedback module, and an output module; The input module includes an L terminal and an N terminal; the L terminal serves as the live wire input terminal, and the N terminal serves as the neutral wire input terminal; the L terminal is connected to the first input terminal of the surge protection temperature control module; the N terminal is connected to the second input terminal of the surge protection temperature control module; the first output terminal of the surge protection temperature control module is connected to the first input terminal of the rectifier and filter module; the second output terminal of the surge protection temperature control module is connected to the second input terminal of the rectifier and filter module; the output terminal of the rectifier and filter module is connected to the first input terminal of the transformer module and the control module respectively; the output terminal of the control module is connected to the second input terminal of the transformer module. The first output terminal of the transformer module is connected to the first input terminal of the output module; the second output terminal of the transformer module is connected to the second input terminal of the output module.

2. The feedback-regulated adaptive switching power supply according to claim 1, characterized in that, The surge protection temperature control module includes a varistor VR1, a fuse F1, and a thermistor NTC1; the L terminal is connected to one end of F1 and the other end is connected to NTC1, and the other end of NTC1 is connected to VR1 and serves as the first output terminal of the surge protection temperature control module; the N terminal is connected to the other end of VR1 and serves as the second output terminal of the surge protection temperature control module.

3. The feedback-regulated adaptive switching power supply according to claim 1, characterized in that, The first input and first output terminals of the rectifier and filter module are connected in parallel with a resistor and a capacitor CX1, which are then connected to ports 2 and 1 of the rectifier bridge BD1, respectively. After rectification by the rectifier bridge, a common-mode inductor LF1 and a filter capacitor EC1 are connected in parallel, and the positive terminal of EC1 is used as the output terminal.

4. The feedback-regulated adaptive switching power supply according to claim 1, characterized in that, The control module includes a control chip U3. The VDD terminal of U3 is connected to capacitor C6, EC5, resistors R22 and R27, respectively. The other end of R27 is connected to the output terminal of the rectifier filter module via R21. The other end of R22 is connected to the cathode of diode D3, and the anode of D3 is connected to port 1 of the inductor and resistor R33. The other end of R33 is connected to the SE1 terminal of U3 and resistor R30, and the other end of R30 is grounded. The other end of C5, the cathode of EC5, and port 2 of the inductor are grounded. The GND terminal of U3 is grounded. The FB pin of U3 is connected to resistor R18. The other end of R18 is connected to the optocoupler... The collector of transistor U1 is connected to capacitor C9; the emitter of U1 and the other end of C9 are grounded; the CS terminal of U3 is connected to capacitor C10 and resistor R1 respectively; the other end of C10 is grounded; the other end of R1 is connected to the drain of MOSFET Q1 and grounded after passing through a protection resistor; R2 is connected in parallel between the gate and drain of Q1; the gate of Q1 is connected to diode D1 and resistor R3 respectively; the other ends of D1 and R3 are connected to the GATE terminal of U3; the drain of Q1 is grounded by resistor R7; capacitor C4 is connected in parallel between the drain and source of Q1; the source of Q1 is connected as the output terminal of the control module and connected to the second input terminal of the transformer module.

5. The feedback-regulated adaptive switching power supply according to claim 1, characterized in that, The transformer module includes a transformer T1; the output module includes a feedback module and a filter protection module. The input terminal of the feedback module is connected to the first output terminal of the transformer module; the output terminal includes a positive voltage output terminal V+ and a negative voltage output terminal V-. The first input terminal of the rectifier filter module is connected to the 3-port of transformer T1 through a spike current absorption circuit. The first output terminal of the transformer module is rectified and then connected in parallel with the second output terminal of the transformer module to a filter protection module and a feedback module. The positive voltage output terminal V+ and the negative voltage output terminal V- are respectively connected through a common-mode inductor. The filter protection module includes a filter capacitor, a filter resistor, a bidirectional breakdown diode and a common-mode inductor. The feedback module includes an LED U5 and a voltage regulator U4 in the optocoupler; the input signal is connected to the negative terminal of the voltage regulator through U5 and to the reference terminal of U4 through a resistor, and the positive terminal of U4 is grounded.

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