A switching power supply voltage regulation and protection circuit

Abstract

This utility model discloses a voltage regulation and protection circuit for a switching power supply, relating to the field of switching power supply technology. It includes a power control module that controls the transmission of incoming DC power, adjusting and transmitting the power to an output module. A feedback module samples and compares the voltage of the power input to the output module and provides a feedback signal. The switching power supply module then performs high-frequency transformation based on the feedback signal to provide voltage regulation. A voltage regulation detection module samples the voltage of the output module and compares the sampled signal with a voltage threshold set by the feedback module to detect voltage changes. If the sampled signal remains above or below the voltage threshold for a set time interval, the power control module is controlled to perform a power-off protection. This utility model's switching power supply voltage regulation and protection circuit improves the voltage regulation safety of switching power supplies.

Description

Technical Field

[0001] This utility model relates to the field of switching power supply technology, specifically a switching power supply voltage regulation and protection circuit. Background Technology

[0002] A switching power supply is a high-frequency power conversion device, consisting of an input power conversion device, a high-frequency transformer, an output power conversion device, and a voltage feedback device. The voltage feedback device samples the output, and the high-frequency transformer performs voltage regulation based on the feedback signal to meet the voltage regulation requirements of the switching power supply. However, when the voltage feedback device malfunctions, it may cause the high-frequency transformer to frequently adjust the output voltage, leading to unstable power output from the switching power supply, reduced lifespan, and decreased power supply safety. Therefore, improvements are needed. Utility Model Content

[0003] This utility model provides a switching power supply voltage regulation and protection circuit to solve the problems mentioned in the background art.

[0004] To achieve the above objectives, this utility model provides the following technical solution:

[0005] A voltage regulation and protection circuit for a switching power supply includes: a power control module, a switching power supply module, an output module, a feedback module, and a voltage regulation detection module.

[0006] The power control module is used to receive DC power and control the transmission of power.

[0007] The switching power supply module is connected to the power control module and the feedback module. It is used to receive the feedback signal output by the feedback module, perform high-frequency voltage regulation on the DC power transmitted by the power control module, and output the first power.

[0008] The output module, connected to the switching power supply module, is used to rectify and filter the first electrical energy and output the second electrical energy.

[0009] The feedback module, connected to the output module, is used to sample the voltage of the second electrical energy, compare the sampled signal with a set voltage threshold, and output a feedback signal when the voltage of the sampled signal is not equal to the set voltage threshold.

[0010] The voltage regulation detection module, connected to the power control module, output module, and feedback module, is used to set a timer, perform voltage division sampling of the second electrical energy, and control the power control module to perform power-off protection when the voltage of the sampled signal is not equal to the voltage threshold for a period exceeding the timer.

[0011] As a further embodiment of this utility model: the power control module includes a power interface, a first capacitor, a first resistor, a first power transistor, and a first switching transistor;

[0012] Preferably, the first end of the power interface is connected to the drain of the first power transistor and one end of the first capacitor, and is connected to the gate of the first power transistor and the collector of the first switching transistor through the first resistor. The emitter of the first switching transistor is connected to the other end of the first capacitor, the second end of the power interface and the ground terminal. The base of the first switching transistor is connected to the voltage regulation detection module.

[0013] As a further embodiment of this utility model: the switching power supply module includes a first driver, a second power transistor, and a first transformer; the output module includes a first diode, a second diode, a second capacitor, and an output port;

[0014] Preferably, the first end of the primary side of the first transformer is connected to the VCC terminal of the first driver, the second end of the primary side of the first transformer is connected to the drain of the second power transistor, the source of the second power transistor is connected to the GND terminal of the first driver and the second terminal of the power interface, the gate of the second power transistor is connected to the OUT terminal of the first driver, the first end of the secondary side of the first transformer is connected to the anode of the first diode, the cathode of the first diode is connected to the cathode of the second diode and the first end of the output port, and is connected to the second end of the output port, the anode of the second diode and the second end of the secondary side of the first transformer through the second capacitor.

[0015] As a further embodiment of this utility model: the feedback module includes a second resistor, a third resistor, a first optocoupler, a fourth capacitor, a third capacitor, a fourth resistor, a fifth resistor, a sixth resistor, a first voltage regulator, and a first reference power supply;

[0016] Preferably, one end of the second resistor is connected to the first end of the output port and is connected to one end of the third capacitor, the second end of the first optocoupler, and the cathode of the first voltage regulator through the third resistor. The other end of the third capacitor is connected to the first end of the sixth resistor, the control terminal of the first voltage regulator, one end of the fifth resistor, and the voltage regulation detection module through the fourth resistor. The other end of the fifth resistor is connected to the first reference power supply. The other end of the sixth resistor is connected to the anode and ground of the first voltage regulator. The third end of the first optocoupler is connected to the FB terminal of the first driver and is connected to the fourth end of the first optocoupler and ground through the fourth capacitor.

[0017] As a further improvement of this utility model: the voltage regulation detection module includes a seventh resistor, an eighth resistor, a first comparator, a second comparator, and a first logic chip;

[0018] Preferably, the inverting input of the first comparator is connected to the non-inverting input of the second comparator and one end of the eighth resistor, and is connected to the first end of the output port through the seventh resistor. The other end of the eighth resistor is grounded. The inverting input of the first comparator is connected to the inverting input of the second comparator and the first end of the sixth resistor. The outputs of the first comparator and the second comparator are respectively connected to the A and B ends of the first logic chip.

[0019] As a further improvement of this utility model, the voltage regulation detection module also includes a fifth capacitor, a ninth resistor, a tenth resistor, a second switching transistor, and a first power supply;

[0020] Preferably, one end of the fifth capacitor is connected to the base of the second switching transistor and the Y terminal of the first logic chip, and is connected to the other end of the fifth capacitor, one end of the tenth resistor and ground through the ninth resistor. The other end of the tenth resistor is connected to the base of the first switching transistor and the emitter of the second switching transistor, and the collector of the second switching transistor is connected to the first power supply.

[0021] Compared with the prior art, the beneficial effects of this utility model are as follows: The voltage regulation protection circuit of this utility model can use a feedback module to sample and compare the voltage of the electrical energy input to the output module and provide a feedback signal. The switching power supply module performs high-frequency transformation processing based on the feedback signal to provide voltage regulation. The voltage regulation detection module samples the voltage of the output module and detects the voltage regulation change by comparing the sampled signal with the voltage threshold set by the feedback module. When the sampled signal is higher or lower than the voltage threshold for a period of time exceeding the set time, the power control module will be controlled to perform power-off protection, thereby improving the voltage regulation safety of the switching power supply. Attached Figure Description

[0022] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the description of the embodiments of this utility model will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a schematic block diagram of a switching power supply voltage regulation and protection circuit provided for this utility model embodiment.

[0024] Figure 2 A circuit diagram of a switching power supply voltage regulation and protection circuit provided for this utility model embodiment.

[0025] Figure 3 The connection circuit diagram of the voltage regulation detection module provided for this utility model embodiment. Detailed Implementation

[0026] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0027] In one embodiment, see Figure 1 A switching power supply voltage regulation and protection circuit includes: a power control module 1, a switching power supply module 2, an output module 3, a feedback module 4, and a voltage regulation detection module 5.

[0028] Specifically, the power control module 1 is used to connect to DC power and control the transmission of power;

[0029] The switching power supply module 2 is connected to the power control module 1 and the feedback module 4. It is used to receive the feedback signal output by the feedback module 4, perform high-frequency voltage regulation on the DC power transmitted by the power control module 1, and output the first power.

[0030] Output module 3, connected to switching power supply module 2, is used to rectify and filter the first electrical energy and output the second electrical energy;

[0031] Feedback module 4, connected to output module 3, is used to sample the voltage of the second electrical energy, compare the sampled signal with a set voltage threshold, and output a feedback signal when the voltage of the sampled signal is not equal to the set voltage threshold.

[0032] The voltage regulation detection module 5 is connected to the power control module 1, the output module 3 and the feedback module 4. It is used to set the timing period, perform voltage division sampling on the second electrical energy, and control the power control module 1 to perform power-off protection when the voltage of the sampled signal is not equal to the voltage threshold for a period of time exceeding the timing period.

[0033] In a specific embodiment, the power control module 1 can be a power control circuit composed of a power interface, a field-effect transistor, a transistor, etc., which can be connected to DC power and perform power transmission control; the switching power supply module 2 can be a switching power supply circuit composed of a pulse driver, a field-effect transistor, and a transformer, which can perform high-frequency voltage regulation; the output module 3 can be an output circuit composed of an output port, a diode, and a capacitor, which can perform rectification, filtering, and power output processing; the feedback module 4 can be a feedback circuit composed of a resistor, a voltage regulator, an optocoupler, a capacitor, etc., which can set a voltage threshold and compare the voltage threshold with the voltage of the sampled signal, and provide a feedback signal; the voltage regulation detection module 5 can be a voltage regulation detection circuit composed of a comparator, a resistor, a logic chip, a transistor, etc., which can perform voltage division sampling on the power after rectification and filtering by the output module 3 and detect the voltage of the sampled signal and the voltage threshold, and set a timing period to determine whether the duration of the difference between the sampled signal and the voltage threshold exceeds the timing period.

[0034] In another embodiment, please refer to Figure 1 , Figure 2 and Figure 3The power control module 1 includes a power interface, a first capacitor C1, a first resistor R1, a first power transistor Q1, and a first switching transistor V1.

[0035] Specifically, the first end of the power interface is connected to the drain of the first power transistor Q1 and one end of the first capacitor C1, and is connected to the gate of the first power transistor Q1 and the collector of the first switching transistor V1 through the first resistor R1. The emitter of the first switching transistor V1 is connected to the other end of the first capacitor C1, the second end of the power interface and the ground. The base of the first switching transistor V1 is connected to the voltage regulation detection module 5.

[0036] In a specific embodiment, the first power transistor Q1 can be an N-channel MOSFET; the first switching transistor V1 can be an NPN transistor.

[0037] Furthermore, the switching power supply module 2 includes a first driver IC1, a second power transistor Q2, and a first transformer B1; the output module 3 includes a first diode D1, a second diode D2, a second capacitor C2, and an output port;

[0038] Specifically, the first end of the primary side of the first transformer B1 is connected to the VCC terminal of the first driver IC1, the second end of the primary side of the first transformer B1 is connected to the drain of the second power transistor Q2, the source of the second power transistor Q2 is connected to the GND terminal of the first driver IC1 and the second terminal of the power interface, the gate of the second power transistor Q2 is connected to the OUT terminal of the first driver IC1, the first end of the secondary side of the first transformer B1 is connected to the anode of the first diode D1, the cathode of the first diode D1 is connected to the cathode of the second diode D2 and the first terminal of the output port, and is connected to the second terminal of the output port, the anode of the second diode D2 and the second end of the secondary side of the first transformer B1 through the second capacitor C2.

[0039] In a specific embodiment, the first driver IC1 can be a UC3842 driver; the second power transistor Q2 can be an N-channel MOSFET.

[0040] Furthermore, the feedback module 4 includes a second resistor R2, a third resistor R3, a first optocoupler IC3, a fourth capacitor C4, a third capacitor C3, a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, a first voltage regulator IC2, and a first reference power supply VREF.

[0041] Specifically, one end of the second resistor R2 is connected to the first end of the output port and is connected to one end of the third capacitor C3, the second end of the first optocoupler IC3, and the cathode of the first voltage regulator IC2 through the third resistor R3. The other end of the third capacitor C3 is connected to the first end of the sixth resistor R6, the control terminal of the first voltage regulator IC2, one end of the fifth resistor R5, and the voltage regulation detection module 5 through the fourth resistor R4. The other end of the fifth resistor R5 is connected to the first reference power supply VREF. The other end of the sixth resistor R6 is connected to the anode and ground of the first voltage regulator IC2. The third end of the first optocoupler IC3 is connected to the FB terminal of the first driver IC1 and is connected to the fourth end and ground of the first optocoupler IC3 through the fourth capacitor C4.

[0042] In a specific embodiment, the first optocoupler IC3 can be a PC817 optocoupler; the first voltage regulator IC2 can be a TL431 voltage regulator; and the first reference power supply VREF sets a voltage threshold, which is the required input-output voltage value of the module 3.

[0043] Furthermore, the voltage regulation detection module 5 includes a seventh resistor R7, an eighth resistor R8, a first comparator A1, a second comparator A2, and a first logic chip J1;

[0044] Specifically, the inverting input of the first comparator A1 is connected to the non-inverting input of the second comparator A2 and one end of the eighth resistor R8, and is connected to the first end of the output port through the seventh resistor R7. The other end of the eighth resistor R8 is grounded. The inverting input of the first comparator A1 is connected to the inverting input of the second comparator A2 and the first end of the sixth resistor R6. The outputs of the first comparator A1 and the second comparator A2 are respectively connected to the A and B ends of the first logic chip J1.

[0045] In a specific embodiment, both the first comparator A1 and the second comparator A2 can be selected as LM358 comparators; the first logic chip J1 can be selected as an XOR gate chip.

[0046] Furthermore, the voltage regulation detection module 5 also includes a fifth capacitor C5, a ninth resistor R9, a tenth resistor R10, a second switching transistor V2, and a first power supply VCC1;

[0047] Specifically, one end of the fifth capacitor C5 is connected to the base of the second switch V2 and the Y terminal of the first logic chip J1, and is connected to the other end of the fifth capacitor C5, one end of the tenth resistor R10 and the ground terminal through the ninth resistor R9. The other end of the tenth resistor R10 is connected to the base of the first switch V1 and the emitter of the second switch V2. The collector of the second switch V2 is connected to the first power supply VCC1.

[0048] In a specific embodiment, the second switching transistor V2 can be an NPN transistor.

[0049] In this embodiment of a switching power supply voltage regulation and protection circuit, DC power is input through a power interface. A first power transistor Q1 transmits power, and the conduction state of Q1 is controlled by a first driver IC1. This, in conjunction with a first transformer B1, performs high-frequency voltage transformation. Rectification and filtering are performed by a first diode D1, a second diode D2, and a second capacitor C2. The output port receives the power, and the voltage is sampled by a second resistor R2, a third resistor R3, a first voltage regulator IC2, a third capacitor C3, a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, and a first reference power supply VREF. The sampled signal is compared with a voltage threshold set by the first reference power supply VREF, thereby controlling the conduction state of the first optocoupler IC3, which then... The first driver IC1 provides a feedback signal at its FB terminal. The first driver IC1 adjusts the conduction state of the first power transistor Q1, thereby adjusting the output voltage. At the same time, the seventh resistor R7 and the eighth resistor R8 sample the output power. The sampled signal is compared with the voltage threshold by the first comparator A1 and the second comparator A2. When the sampled signal is not equal to the voltage threshold, the first logic chip J1 outputs a high level. The fifth capacitor C5, the second switch V2, and the ninth resistor R9 set a timing time. That is, when the power stored in the fifth capacitor C5 reaches the conduction voltage of the second switch V2, the timing time is reached, which will trigger the first switch V1 to conduct, causing the first power transistor Q1 to turn off, and the switching power supply to stop supplying power.

[0050] It will be apparent to those skilled in the art that this invention is not limited to the details of the exemplary embodiments described above, and that it can be implemented in other specific forms without departing from the spirit or essential characteristics of this invention. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of this invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within this invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0051] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A voltage regulation and protection circuit for a switching power supply, characterized in that, The switching power supply voltage regulation and protection circuit includes: a power control module, a switching power supply module, an output module, a feedback module, and a voltage regulation detection module; The power control module is used to receive DC power and control the transmission of power. The switching power supply module is connected to the power control module and the feedback module, and is used to receive the feedback signal output by the feedback module, perform high-frequency voltage regulation on the DC power transmitted by the power control module, and output the first power. The output module is connected to the switching power supply module and is used to rectify and filter the first electrical energy and output the second electrical energy. The feedback module is connected to the output module and is used to sample the voltage of the second electrical energy, compare the sampled signal with a set voltage threshold, and output a feedback signal when the voltage of the sampled signal is not equal to the set voltage threshold. The voltage regulation detection module is connected to the power control module, output module and feedback module. It is used to set a timer, perform voltage division sampling of the second electrical energy, and control the power control module to perform power-off protection when the voltage of the sampled signal is not equal to the voltage threshold for a period of time exceeding the timer.

2. The switching power supply voltage regulation and protection circuit according to claim 1, characterized in that, The power control module includes a power interface, a first capacitor, a first resistor, a first power transistor, and a first switching transistor. The first end of the power interface is connected to the drain of the first power transistor and one end of the first capacitor, and is connected to the gate of the first power transistor and the collector of the first switching transistor through the first resistor. The emitter of the first switching transistor is connected to the other end of the first capacitor, the second end of the power interface and the ground. The base of the first switching transistor is connected to the voltage regulation detection module.

3. The switching power supply voltage regulation and protection circuit according to claim 2, characterized in that, The switching power supply module includes a first driver, a second power transistor, and a first transformer; the output module includes a first diode, a second diode, a second capacitor, and an output port. The first end of the primary side of the first transformer is connected to the VCC terminal of the first driver, the second end of the primary side of the first transformer is connected to the drain of the second power transistor, the source of the second power transistor is connected to the GND terminal of the first driver and the second terminal of the power interface, the gate of the second power transistor is connected to the OUT terminal of the first driver, the first end of the secondary side of the first transformer is connected to the anode of the first diode, the cathode of the first diode is connected to the cathode of the second diode and the first end of the output port, and is connected to the second end of the output port, the anode of the second diode and the second end of the secondary side of the first transformer through the second capacitor.

4. The switching power supply voltage regulation and protection circuit according to claim 3, characterized in that, The feedback module includes a second resistor, a third resistor, a first optocoupler, a fourth capacitor, a third capacitor, a fourth resistor, a fifth resistor, a sixth resistor, a first voltage regulator, and a first reference power supply. One end of the second resistor is connected to the first end of the output port and is connected to one end of the third capacitor, the second end of the first optocoupler, and the cathode of the first voltage regulator through the third resistor. The other end of the third capacitor is connected to the first end of the sixth resistor, the control terminal of the first voltage regulator, one end of the fifth resistor, and the voltage regulation detection module through the fourth resistor. The other end of the fifth resistor is connected to the first reference power supply. The other end of the sixth resistor is connected to the anode of the first voltage regulator and ground. The third end of the first optocoupler is connected to the FB terminal of the first driver and is connected to the fourth end of the first optocoupler and ground through the fourth capacitor.

5. The switching power supply voltage regulation and protection circuit according to claim 4, characterized in that, The voltage regulation detection module includes a seventh resistor, an eighth resistor, a first comparator, a second comparator, and a first logic chip; The inverting input of the first comparator is connected to the non-inverting input of the second comparator and one end of the eighth resistor, and is connected to the first end of the output port through the seventh resistor. The other end of the eighth resistor is grounded. The inverting input of the first comparator is connected to the inverting input of the second comparator and the first end of the sixth resistor. The outputs of the first comparator and the second comparator are respectively connected to the A and B ends of the first logic chip.

6. The switching power supply voltage regulation and protection circuit according to claim 5, characterized in that, The voltage regulation detection module also includes a fifth capacitor, a ninth resistor, a tenth resistor, a second switching transistor, and a first power supply; One end of the fifth capacitor is connected to the base of the second switching transistor and the Y terminal of the first logic chip, and is connected to the other end of the fifth capacitor, one end of the tenth resistor and ground through the ninth resistor. The other end of the tenth resistor is connected to the base of the first switching transistor and the emitter of the second switching transistor. The collector of the second switching transistor is connected to the first power supply.

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