Power supply control circuit and power supply
By using a switching assembly consisting of MOSFETs and transistors in the power supply, the control circuit turns off the switching circuit when there is a reverse electromotive force, which solves the overvoltage problem caused by the reverse electromotive force of the power supply, achieves efficient and low-cost backflow prevention, and ensures the normal operation of the power supply.
Patent Information
- Application Number
- CN202520132783.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-20
- Publication Date
- 2026-02-03
- Estimated Expiration
- 2035-01-20
AI Technical Summary
In motor drive power supplies, if the reverse electromotive force voltage exceeds the rated output voltage of the power supply, it will trigger the overvoltage protection or affect the feedback loop, causing the power controller to stop operating. Existing solutions such as diodes to prevent voltage reverse flow are inefficient and costly, while MOSFET solutions are complex and space-consuming.
By employing a switching circuit and a control circuit, and utilizing a switching assembly composed of MOSFET switching transistors and bipolar transistors, the control circuit turns off the switching circuit when the output voltage is greater than the input voltage, thus preventing voltage/current reverse flow and achieving efficient and low-cost reverse flow prevention.
It effectively prevents voltage/current backflow, maintains normal power supply operation, reduces cost and space occupation, improves efficiency, and avoids power supply damage.
Smart Images
Figure CN223872045U_ABST
Abstract
Description
Technical Field
[0001] The embodiments disclosed in this application relate to the field of power supply, and more specifically, to a power control circuit and a power supply. Background Technology
[0002] In some motor drive power supplies, a back electromotive force (EMF) is generated when the motor decelerates or stops abruptly. For example, in the power supplies of medical ventilators or oxygen concentrators, a back EMF is generated due to the rapid change in the operating state of the compressor at the device end. The back EMF voltage usually exceeds the rated output voltage of the power supply, causing the power supply to trigger overvoltage protection or affecting the power supply's feedback loop, leading to the power supply controller malfunctioning and causing damage to the power supply equipment. Utility Model Content
[0003] According to embodiments of this application, this application proposes a circuit and a power supply to solve the above-mentioned problems.
[0004] The first aspect of this application discloses a power control circuit applied to a power supply, the power supply including an input terminal, an output terminal, and a power circuit connected to the input terminal. The power control circuit includes: a switching circuit connected to the input terminal and the output terminal; and a control circuit connected to the switching circuit and the output terminal. When the voltage at the output terminal is greater than the voltage at the input terminal, the control circuit controls the switching circuit to turn off to prevent voltage / current reverse flow between the output terminal and the input terminal.
[0005] In some embodiments, the input terminal includes a positive input pin and a negative input pin, and the output terminal includes a positive output pin and a negative output pin, wherein the positive input pin corresponds to the positive output pin, and the negative input pin corresponds to the negative output pin.
[0006] In some embodiments, the power control circuit further includes a preset input terminal; the switching circuit includes a first switching component, wherein a first end of the first switching component is connected to the positive input pin, a second end of the first switching component is connected to the positive output pin, and a third end of the first switching component is connected to the preset input terminal.
[0007] In some embodiments, the switching circuit further includes a first resistor, wherein a third terminal of the first switching component is connected to the preset input terminal via the first resistor.
[0008] In some embodiments, the control circuit includes a second switching assembly and a second resistor;
[0009] Wherein, the first end of the second switch component is connected to the preset input terminal through the second resistor, the second end of the second switch component is connected to the second end of the first switch component, the third end of the second switch component is connected to the first end of the first switch component, and the fourth end of the second switch component is connected to the third end of the first switch component.
[0010] In some embodiments, the switching circuit includes a first switching component, wherein a first end of the first switching component is connected to the negative output pin, a second end of the first switching component is connected to the negative input pin, and a third end of the first switching component is connected to the positive input pin.
[0011] In some embodiments, the switching circuit further includes a first resistor, wherein a third terminal of the first switching assembly is connected to the positive input pin via the first resistor.
[0012] In some embodiments, the control circuit includes a second switch assembly and a second resistor; wherein a first terminal of the second switch assembly is connected to the positive input pin through the second resistor, a second terminal of the second switch assembly is connected to a second terminal of the first switch assembly, a third terminal of the second switch assembly is connected to a first terminal of the first switch assembly, and a fourth terminal of the second switch assembly is connected to a third terminal of the first switch assembly.
[0013] In some embodiments, the second switching component includes a first transistor and a second transistor; the emitter of the first transistor is connected to the second resistor, the collector of the first transistor is connected to the second terminal of the first switching component, and the base of the first transistor is connected to the base of the second transistor and the emitter of the first transistor; the emitter of the second transistor is connected to the first terminal of the first switching component, the collector of the second transistor is connected to the third terminal of the first switching component, and the base of the second transistor is connected to the base of the first transistor and the emitter of the first transistor; wherein, the emitter of the first transistor is the first terminal of the second switching component, the collector of the first transistor is the second terminal of the second switching component, the emitter of the second transistor is the third terminal of the second switching component, and the collector of the second transistor is the fourth terminal of the second switching component.
[0014] In some embodiments, the control circuit further includes a Zener diode, the anode of which is connected to the third terminal of the second switching component and the first terminal of the first switching component, and the cathode of which is connected to the fourth terminal of the second switching component and the third terminal of the first switching component.
[0015] In some embodiments, the control circuit further includes a third resistor, the first end of which is connected to the second end of the first switching assembly, and the second end of which is connected to the second end of the second switching assembly.
[0016] The second aspect of this application discloses a power supply, including: an input terminal, an output terminal, a power supply circuit connected to the input terminal, and a power control circuit as described in the first aspect.
[0017] The beneficial effects of this application are as follows: The power control circuit includes a switching circuit and a control circuit. The power control circuit is applied to the power supply. The switching circuit connects the input terminal and the output terminal of the power supply. The control circuit is connected to the switching circuit and the output terminal. When the voltage at the output terminal is greater than the voltage at the input terminal, the control circuit controls the switching circuit to turn off, which can prevent voltage / current backflow between the output terminal and the input terminal. The control circuit achieves high-efficiency and low-cost protection against voltage / current backflow. Attached Figure Description
[0018] The present application will be further described below with reference to the accompanying drawings and embodiments. In the drawings:
[0019] Figure 1 This is a schematic diagram of the power control circuit according to an embodiment of this application;
[0020] Figure 2 This is a circuit diagram of a power control circuit according to an embodiment of this application;
[0021] Figure 3 This is a circuit diagram of a second switching component according to an embodiment of this application;
[0022] Figure 4 This is a circuit diagram of a power control circuit according to another embodiment of this application;
[0023] Figure 5 This is a circuit diagram of the second switching component according to yet another embodiment of this application.
[0024] The reference numerals in the accompanying drawings of the specific embodiments are as follows:
[0025] Power control circuit 100, switching circuit 110, control circuit 120, power supply 200, input terminal 210, output terminal 220, power supply circuit 230, positive input pin VIN+, negative input pin VIN-, positive output pin VOUT+, negative output pin VOUT-, preset input terminal Vbias, first switching component QS1, first resistor R1, second switching component QS2, second resistor R2, first transistor Q1, second transistor Q2, pin 1, pin 2, pin 3, pin 4, pin 5, pin 6, Zener diode ZD1, third resistor R3, capacitor EC1, capacitor C1. Detailed Implementation
[0026] In this application, the reference to "embodiment" means that a specific feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.
[0027] In this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent three cases: A alone, A and B simultaneously, and B alone. Additionally, the character " / " generally indicates that the preceding and following related objects are in an "or" relationship. Furthermore, "many" in this application means two or more. Moreover, the term "at least one" in this application means any combination of at least two of any one or more of a plurality of objects. For example, including at least one of A, B, and C can mean including any one or more elements selected from the set consisting of A, B, and C. Furthermore, the terms "first," "second," and "third" in this application are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features.
[0028] If the reverse electromotive force voltage exceeds the power supply's rated output voltage, it triggers overvoltage protection or affects the power supply's feedback loop, causing the power supply controller to stop operating and the output voltage to drop to 0V. Typically, a diode is added to the power supply's output terminal to prevent reverse voltage flow. Although diodes are a simple and effective way to prevent reverse voltage and current flow, they also have limitations due to voltage fluctuations. f High resistance leads to very high conduction losses, low efficiency, and requires a large heatsink. Alternatively, a MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor) can be used instead of a diode. MOSFETs have low on-resistance, high efficiency, and low operating temperature, eliminating the need for a heatsink. However, complex control circuitry is still required to control the MOSFET's on / off state, achieving the same voltage and current protection as a diode. This may require comparators, dedicated ICs (integrated circuits), and signal acquisition circuitry, resulting in high cost, complex circuitry, and significant PCB (Printed Circuit Board) space consumption.
[0029] Therefore, this application provides a power control circuit and a power supply to solve the above-mentioned problems.
[0030] To enable those skilled in the art to better understand the technical solution of this application, the technical solution of this application will be further described in detail below with reference to the accompanying drawings and specific embodiments.
[0031] Please see Figure 1 , Figure 1 This is a schematic diagram of the power control circuit according to an embodiment of this application. The power control circuit 100 is applied to the power supply 200, and the power control circuit 100 includes a switching circuit 110 and a control circuit 120. The power supply 200 includes an input terminal 210, an output terminal 220, and a power circuit 230 connected to the input terminal 210. The switching circuit 110 connects the input terminal 210 and the output terminal 220, and the control circuit 120 is connected to the switching circuit 110 and the output terminal 220.
[0032] Specifically, when the voltage at output terminal 220 is greater than the voltage at input terminal 210, the control circuit 120 controls the switch circuit 110 to turn off to prevent voltage / current reverse flow between output terminal 220 and input terminal 210. For example, if the voltage at output terminal 220 is greater than the voltage at input terminal 210, a reverse electromotive force is generated between input terminal 210 and output terminal 220. At this time, under the control of the control circuit 120, the switch circuit 110 is in the open state, which can prevent reverse voltage / current from flowing back into the power supply, allowing the power supply 200 to operate normally. Conversely, when the power supply 200 is operating normally, for example, when the voltage at output terminal 220 is less than or equal to the voltage at input terminal 210, the switch circuit 110 is in the closed state.
[0033] In this embodiment, the power control circuit 100 is applied to the power supply 200. The power control circuit 100 includes a switching circuit 110 and a control circuit 120. The switching circuit 110 is connected to the input terminal 210 and the output terminal 220. The control circuit 120 is connected to the switching circuit 110 and the output terminal 220. When the voltage at the output terminal 220 is greater than the voltage at the input terminal 210, the control circuit 120 controls the switching circuit 110 to turn off, which can prevent voltage / current reverse flow between the output terminal 220 and the input terminal 210. The control circuit 120 achieves high-efficiency and low-cost prevention of voltage / current reverse flow.
[0034] Please see Figure 2 , Figure 2 This is a circuit diagram of a power control circuit according to an embodiment of this application. In some embodiments, such as... Figures 1-2As shown, input terminal 210 includes a positive input pin VIN+ and a negative input pin VIN-, and output terminal 220 includes a positive output pin VOUT+ and a negative output pin VOUT-, wherein the positive input pin VIN+ corresponds to the positive output pin VOUT+, and the negative input pin VIN- corresponds to the negative output pin VOUT-; the power control circuit 100 may also include a preset input terminal Vbias.
[0035] In some embodiments, such as Figure 2 As shown, the switching circuit 110 includes a first switching component QS1, wherein the first terminal of the first switching component QS1 is connected to the positive input pin VIN+, the second terminal of the first switching component QS1 is connected to the positive output pin VOUT+, and the third terminal of the first switching component QS1 is connected to the preset input terminal Vbias.
[0036] For example, the first switching component QS1 can be a MOSFET switch. The first terminal of the first switching component QS1 can be the source (S) of the MOSFET switch, the second terminal of the first switching component QS1 can be the drain (D) of the MOSFET switch, and the third terminal of the first switching component QS1 can be the gate (G) of the MOSFET switch. In some examples, the source (S) of the MOSFET switch is connected to the positive input pin VIN+, the drain (D) of the MOSFET switch is connected to the positive output pin VOUT+, and the gate (G) of the MOSFET switch is connected to the preset input terminal Vbias.
[0037] In some embodiments, please continue reading Figure 2 The switching circuit 110 may also include a first resistor R1, which may be a bias resistor for the drive voltage of the MOSFET switch.
[0038] The third terminal of the first switching component QS1 is connected to the preset input terminal Vbias through the first resistor R1. For example, the gate G of the MOSFET switch is connected to the preset input terminal Vbias through the first resistor R1.
[0039] In some embodiments, the control circuit 120 includes a second switching component QS2 and a second resistor R2, wherein the second resistor R2 may be a bias resistor that provides a static operating current for the second switching component QS2.
[0040] like Figure 2As shown, the first terminal P1 of the second switching component QS2 is connected to the preset input terminal Vbias through the second resistor R2, the second terminal P2 of the second switching component QS2 is connected to the second terminal of the first switching component QS1 (i.e., the drain D of the MOSFET switch), the third terminal P3 of the second switching component QS2 is connected to the first terminal of the first switching component QS1 (i.e., the source S of the MOSFET switch), and the fourth terminal P4 of the second switching component QS2 is connected to the third terminal of the first switching component QS1 (i.e., the gate G of the MOSFET switch).
[0041] In some embodiments, such as Figure 3 As shown, Figure 3 This is a circuit diagram of a second switching component according to an embodiment of the present application. The second switching component QS2 includes a first transistor Q1 and a second transistor Q2.
[0042] The emitter of the first transistor Q1 ( Figure 3 Pin 4) is connected to the second resistor R2, and the collector of the first transistor Q1 is ( Figure 3 Pin 3) is connected to the second terminal of the first switching assembly QS1 (i.e., the drain D of the MOSFET switch), and the base of the first transistor Q1 ( Figure 3 Pin 5) is connected to the base of the second transistor Q2. Figure 3 Pin 2) and the emitter of the first transistor Q1 ( Figure 3 Pin 4). The emitter of the second transistor Q2 ( Figure 3 Middle pin 1)( Figure 3 Pin 1) is connected to the first terminal of the first switching component QS1 (i.e., the source S of the MOSFET switch) and the collector of the second transistor Q2. Figure 3 Pin 6) is connected to the third terminal of the first switching component QS1 (i.e., the gate G of the MOSFET switch) and the base of the second transistor Q2. Figure 3 Pin 2) is connected to the base of the first transistor Q1. Figure 3 Pin 5) and the emitter of the first transistor Q1 ( Figure 3 (Middle pin 4).
[0043] In some examples, the emitter of the first transistor Q1 ( Figure 3 Pin 4 in the middle is the first terminal P1 of the second switching component QS2, and the collector of the first transistor Q1 ( Figure 3 Pin 3 in the middle is the second terminal P2 of the second switching component QS2, and the emitter of the second transistor Q2 ( Figure 3 Pin 1 is the third terminal P3 of the second switching component QS2, and the collector of the second transistor Q2. Figure 3 Pin 6 in the middle is the fourth terminal P4 of the second switch component QS2.
[0044] In this design, the second switching component QS2 serves as the control transistor for the first switching component QS2. The first transistor Q1 and the second transistor Q2 can be twin transistors, meaning they can have matched / identical parameters and temperature characteristics. Understandably, by short-circuiting the base and emitter of one transistor in the second switching component QS2, the base and collector of that transistor can be used as a diode. For example, by short-circuiting pins 5 and 4 of the first transistor Q1, pins 5-3 of the first transistor Q1 can be used as a diode.
[0045] In some examples, when power supply 200 is operating normally, the second resistor R2 can provide a static bias current for pins 5-3 of the second switching component QS2, resulting in a stable bias voltage V. bc Correspondingly, during the backflow prevention operation, the second resistor R2 can provide base current to pins 2-1 of the second switching component QS2.
[0046] In this embodiment of the application, the V of the second transistor Q2 is utilized. be (Pin 2 - Pin 1) and the V of the first transistor Q1 bc Compared to (pins 5-3), it achieves a comparator-like function, thereby preventing backflow when a reverse electromotive force appears in power supply 200.
[0047] Please see Figure 4 , Figure 4 This is a circuit diagram of a power control circuit according to another embodiment of this application. In some embodiments, such as Figure 1 and Figure 4 As shown, in the power supply 200, the input terminal 210 includes a positive input pin VIN+ and a negative input pin VIN-, and the output terminal 220 includes a positive output pin VOUT+ and a negative output pin VOUT-. The positive input pin VIN+ corresponds to the positive output pin VOUT+, and the negative input pin VIN- corresponds to the negative output pin VOUT-.
[0048] In some embodiments, such as Figure 4 As shown, the switching circuit 110 includes a first switching component QS1, wherein the first terminal of the first switching component QS1 is connected to the negative output pin VOUT-, the second terminal of the first switching component QS1 is connected to the negative input pin VIN-, and the third terminal of the first switching component QS1 is connected to the positive input pin VIN+.
[0049] For example, the first switching component QS1 can be a MOSFET switch. The first terminal of the first switching component QS1 can be the source (S) of the MOSFET switch, the second terminal of the first switching component QS1 can be the drain (D) of the MOSFET switch, and the third terminal of the first switching component QS1 can be the gate (G) of the MOSFET switch. In some examples, the source (S) of the MOSFET switch is connected to the negative output pin VOUT-, the drain (D) of the MOSFET switch is connected to the negative input pin VIN-, and the gate (G) of the MOSFET switch is connected to the positive input pin VIN+.
[0050] In some embodiments, please continue reading Figure 4 The switching circuit 110 also includes a first resistor R1, which can be a drive voltage bias resistor for the MOSFET switch.
[0051] The third terminal of the first switching component QS1 is connected to the positive input pin VIN+ through the first resistor R1. For example, the gate G of the MOSFET switch is connected to the positive input pin VIN+ through the first resistor R1.
[0052] In some embodiments, the control circuit 120 includes a second switching component QS2 and a second resistor R2. For example... Figure 4 As shown, the first terminal P1 of the second switching component QS2 is connected to the positive input pin VIN+ through the second resistor R2. The second terminal P2 of the second switching component QS2 is connected to the second terminal of the first switching component QS1 (i.e., the drain D of the MOSFET switch). The third terminal P3 of the second switching component QS2 is connected to the first terminal of the first switching component QS1 (i.e., the source S of the MOSFET switch). The fourth terminal P4 of the second switching component QS2 is connected to the third terminal of the first switching component QS1 (i.e., the gate G of the MOSFET switch).
[0053] In some embodiments, such as Figure 5 As shown, Figure 5 This is a circuit diagram of a second switching component according to another embodiment of the present application. The second switching component QS2 includes a first transistor Q1 and a second transistor Q2.
[0054] Among them, the emitter of the first transistor Q1 ( Figure 5 Pin 4) is connected to the second resistor R2, and the collector of the first transistor Q1 is ( Figure 5 Pin 3) is connected to the second terminal of the first switching assembly QS1 (i.e., the drain D of the MOSFET switch), and the base of the first transistor Q1 ( Figure 5 Pin 5) is connected to the base of the second transistor Q2. Figure 5 Pin 2) and the emitter of the first transistor Q1 ( Figure 5 Pin 4). The emitter of the second transistor Q2 ( Figure 5 Pin 1) is connected to the first terminal of the first switching component QS1 (i.e., the source S of the MOSFET switch) and the collector of the second transistor Q2. Figure 5 Pin 6) is connected to the third terminal of the first switching component QS1 (i.e., the gate G of the MOSFET switch) and the base of the second transistor Q2. Figure 5 Pin 2) is connected to the base of the first transistor Q1. Figure 5 Pin 5) and the emitter of the first transistor Q1 ( Figure 5 (Middle pin 4).
[0055] In some examples, the emitter of the first transistor Q1 ( Figure 5 Pin 4 in the middle is the first terminal P1 of the second switching component QS2, and the collector of the first transistor Q1 ( Figure 5 Pin 3 in the middle is the second terminal P2 of the second switching component QS2, and the emitter of the second transistor Q2 ( Figure 5 Pin 1 is the third terminal P3 of the second switching component QS2, and the collector of the second transistor Q2. Figure 5 Pin 6 in the middle is the fourth terminal P4 of the second switching component QS2. In practical applications, Figures 4-5 The first transistor Q1 and the second transistor Q2 in the above embodiment can be implemented with reference to the description in the above embodiment, and will not be repeated here.
[0056] In some embodiments, such as Figure 1 , Figure 2 and Figure 4 As shown, the control circuit 120 may further include a Zener diode ZD1, the anode of which is connected to the third terminal P3 of the second switching component QS2 and the first terminal of the first switching component QS1 (i.e., the source S of the MOSFET switch), and the cathode of which is connected to the fourth terminal P4 of the second switching component QS2 and the third terminal of the first switching component QS1 (i.e., the gate G of the MOSFET switch).
[0057] In some embodiments, such as Figure 1 , Figure 2 and Figure 4 As shown, the control circuit 120 may further include a third resistor R3. The first end of the third resistor R3 is connected to the second end of the first switching component QS1 (i.e., the drain D of the MOSFET switch), and the second end of the third resistor R3 is connected to the second end P2 of the second switching component QS2. The third resistor R3 can serve as a fine-tuning resistor for the second switching component QS2 (pins 5-3), which can accelerate the function of the second switching component QS2 in controlling the turn-off of the first switching component QS1 and improve the control response speed.
[0058] In some embodiments, the power supply 200 may include an input terminal 210, an output terminal 220, a power supply circuit 230 connected to the input terminal 210, and a power control circuit 100. The power control circuit 100 includes a switching circuit 110 and a control circuit 120. The switching circuit 110 connects the input terminal 210 and the output terminal 220, and the control circuit 120 connects the switching circuit 110 and the output terminal 220. When the voltage at the output terminal 220 is greater than the voltage at the input terminal 210, the control circuit 120 controls the switching circuit 110 to turn off, preventing voltage / current reverse flow between the output terminal 220 and the input terminal 210, thus allowing the power supply 200 to operate normally.
[0059] In some examples, such as Figure 2 and Figure 4 As shown, the power supply 200 may also include capacitor EC1 and capacitor C1. Capacitor EC1 can be the output filter electrolytic capacitor of the power supply 200, used to provide a stable DC output. Capacitor C1 can play a role in preventing static electricity at the output terminal and improving the stability of the circuit.
[0060] To facilitate understanding, an example application scenario of this application embodiment is provided. For instance, when the product is operating normally, Vin+ or Vbias provides a static bias current to the control circuit 120 through the second resistor R2, pins 5-3 of the second switching component QS2, and the third resistor R3, resulting in a stable bias voltage V. bc (Pin 5-Pin 3), this voltage is slightly lower than the threshold voltage V of "Pin 2-Pin 1". be This causes the transistor composed of pins 1-2-6 of the second switching component QS2 to be in the off state, and the voltage V of the first switching component QS1... gs The drive voltage provided by the first resistor R1 operates in the on state, and the input terminal (Vin) to the output terminal (Vout) is in a connected state, allowing power supply 200 to provide a stable DC output to the system. Since the on-resistance of the MOSFET switch is very low, the overall circuit loss is very small, having almost no impact on the product's efficiency and temperature rise.
[0061] During the operation of the customer's system, when the speed of the motor or compressor changes drastically, such as suddenly dropping from high speed to low speed or even stopping abruptly, a voltage generated by a back electromotive force will appear at the power supply output terminal. At this time, the output voltage of the control circuit 120 will be higher than the input voltage, and the bias voltage V of the second switching component QS2 will also be higher. bc (Pin 5-Pin 3) will then rise, V be(Pin 2-Pin 1) also rises. When it exceeds the threshold voltage of "Pin 2-Pin 1", the transistor composed of "Pin 1-Pin 2-Pin 6" in the second switching component QS2 enters the conducting state, pulling down the voltage V of the first switching component QS1. gs When the voltage reaches 0V, the first switching component QS1 enters the off state, and the back electromotive force voltage at the system end cannot flow back into the internal circuit of power supply 200. The operating state of power supply 200 is not affected by the system / device end.
[0062] When the back electromotive force at the system terminal disappears or decreases, the voltage V bc (Pin 5-Pin 3) decreases accordingly, when this voltage is below V be When the threshold voltage of (pin 2-pin 1) is reached, the transistor composed of "pin 1-pin 2-pin 6" of the second switching component QS2 returns to the cut-off state, and the first switching component QS1 returns to the conducting state. The external power supply can provide power to the system without interruption and will not cause the system power supply to be interrupted.
[0063] Those skilled in the art will understand that, in the above-described method of the specific implementation, the order in which each step is written does not imply a strict execution order and does not constitute any limitation on the implementation process. The specific execution order of each step should be determined by its function and possible internal logic.
[0064] Those skilled in the art will readily recognize that numerous modifications and variations can be made to the apparatus and method while maintaining the teachings of this application. Therefore, the above disclosure should be considered limited only by the scope of the appended claims.
Claims
1. A power supply control circuit, characterized in that, Applied to a power supply, the power supply includes an input terminal, an output terminal, and a power supply circuit connected to the input terminal, the power supply control circuit including: A switching circuit connects the input terminal and the output terminal; A control circuit is connected to the switching circuit and the output terminal; Specifically, when the voltage at the output terminal is greater than the voltage at the input terminal, the control circuit controls the switching circuit to turn off to prevent voltage / current reverse flow between the output terminal and the input terminal.
2. The circuit according to claim 1, characterized in that, The input terminal includes a positive input pin and a negative input pin, and the output terminal includes a positive output pin and a negative output pin, wherein the positive input pin corresponds to the positive output pin, and the negative input pin corresponds to the negative output pin.
3. The circuit according to claim 2, characterized in that, The power control circuit also includes a preset input terminal; The switching circuit includes a first switching component, wherein a first end of the first switching component is connected to the positive input pin, a second end of the first switching component is connected to the positive output pin, and a third end of the first switching component is connected to the preset input terminal.
4. The circuit according to claim 3, characterized in that, The switching circuit further includes a first resistor, wherein the third terminal of the first switching component is connected to the preset input terminal through the first resistor.
5. The circuit according to claim 3, characterized in that, The control circuit includes a second switching assembly and a second resistor; Wherein, the first end of the second switch component is connected to the preset input terminal through the second resistor, the second end of the second switch component is connected to the second end of the first switch component, the third end of the second switch component is connected to the first end of the first switch component, and the fourth end of the second switch component is connected to the third end of the first switch component.
6. The circuit according to claim 2, characterized in that, The switching circuit includes a first switching component, wherein a first end of the first switching component is connected to the negative output pin, a second end of the first switching component is connected to the negative input pin, and a third end of the first switching component is connected to the positive input pin.
7. The circuit according to claim 6, characterized in that, The switching circuit further includes a first resistor, wherein the third terminal of the first switching assembly is connected to the positive input pin through the first resistor.
8. The circuit according to claim 6, characterized in that, The control circuit includes a second switching assembly and a second resistor; Wherein, the first end of the second switch component is connected to the positive input pin through the second resistor, the second end of the second switch component is connected to the second end of the first switch component, the third end of the second switch component is connected to the first end of the first switch component, and the fourth end of the second switch component is connected to the third end of the first switch component.
9. The circuit according to claim 5 or 8, characterized in that, The second switching assembly includes a first transistor and a second transistor; The emitter of the first transistor is connected to the second resistor, the collector of the first transistor is connected to the second terminal of the first switching assembly, and the base of the first transistor is connected to the base of the second transistor and the emitter of the first transistor; the emitter of the second transistor is connected to the first terminal of the first switching assembly, the collector of the second transistor is connected to the third terminal of the first switching assembly, and the base of the second transistor is connected to the base of the first transistor and the emitter of the first transistor; Wherein, the emitter of the first transistor is the first terminal of the second switching assembly, the collector of the first transistor is the second terminal of the second switching assembly, the emitter of the second transistor is the third terminal of the second switching assembly, and the collector of the second transistor is the fourth terminal of the second switching assembly.
10. The circuit according to claim 5 or 8, characterized in that, The control circuit further includes a Zener diode, the anode of which is connected to the third terminal of the second switching assembly and the first terminal of the first switching assembly, and the cathode of which is connected to the fourth terminal of the second switching assembly and the third terminal of the first switching assembly.
11. The circuit according to claim 10, characterized in that, The control circuit further includes a third resistor, the first end of which is connected to the second end of the first switching assembly, and the second end of which is connected to the second end of the second switching assembly.
12. A power supply, characterized in that, It includes an input terminal, an output terminal, a power supply circuit connected to the input terminal, and a power control circuit as described in any one of claims 1-11.