Power supply control circuit
By introducing a reset circuit and a transformer power supply circuit into the power control circuit, the problem of false lock-up of the control chip in small power supplies is solved, enabling normal power-on and stable operation of the power supply, simplifying the circuit structure and reducing costs.
Patent Information
- Application Number
- CN202422971587.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-02
- Publication Date
- 2025-12-12
- Estimated Expiration
- 2034-12-02
AI Technical Summary
In existing small-sized power supplies, the control chip is prone to false lock-up during rapid power-on and power-off processes, causing the power supply to malfunction, affecting stability and reliability, and limiting the application range of DC/DC converters.
A power control circuit including a start-up resistor, an energy storage capacitor, a reset circuit, and a transformer power supply circuit was designed. By adding a reset circuit, the energy storage capacitor is discharged using components such as MOSFETs and diodes, ensuring that the pin voltage of the control chip quickly returns to 0V, thereby achieving chip reset.
This invention achieves normal power-on and stable operation in a small-volume power supply, simplifies the circuit structure, reduces costs, and improves the reliability and stability of the power supply.
Smart Images
Figure CN223666248U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of power supply technology, and more specifically, to a power supply control circuit. Background Technology
[0002] DC / DC power converters are indispensable devices in our lives and industrial sectors, playing a crucial role in various electronic devices. They are primarily used to convert one DC voltage to another, featuring high power and efficiency, small size, and light weight, thus finding wide application in computers, communications, industrial automation, automotive, aerospace, and many other fields.
[0003] DC / DC converters have different requirements in different application scenarios. For example, in communication equipment, DC / DC converters are often used in power management circuits to provide different voltage levels and ensure a stable power supply; in the automotive industry, DC / DC converters can convert the voltage of a car battery into the voltage level required by various in-vehicle electronic devices; in the field of industrial control, DC / DC converters are used to provide different voltage levels required by machines and other equipment; in solar energy applications, DC / DC converters can convert the low voltage output from solar panels into DC power to drive heaters, fans, water pumps, etc.
[0004] However, existing power supply control circuits are relatively complex, especially in small-sized power supplies. The control chip may experience false lock-up during rapid power-on and power-off processes, causing the power supply to malfunction. This problem severely impacts the stability and reliability of the power supply, limiting the application range of DC / DC converters. Utility Model Content
[0005] In order to overcome the problem that the control chip in existing small power supplies may experience false lock-up during rapid power-on and power-off processes, causing the power supply to malfunction, this utility model provides a power control circuit.
[0006] The technical solution of this utility model is as follows:
[0007] A power control circuit includes a start-up resistor, a control chip, an energy storage capacitor, a reset circuit, and a transformer power supply circuit. The start-up resistor is disposed between the input voltage terminal and the energy storage capacitor. The energy storage capacitor is connected to the control chip and also to the reset circuit. The reset circuit is used to discharge the energy storage capacitor. The reset circuit is connected to the transformer power supply circuit, which is used to control the opening and closing of the reset circuit.
[0008] According to the present invention based on the above scheme, the first end of the energy storage capacitor is connected to the first pin of the control chip, and the second end of the energy storage capacitor is connected to the fifth pin of the control chip.
[0009] According to the present invention based on the above scheme, the reset circuit includes a MOS transistor and a thirty-ninth resistor. The source of the MOS transistor is connected to the first terminal of the energy storage capacitor and the source of the MOS transistor is grounded. The drain of the MOS transistor is connected to the first terminal of the thirty-ninth resistor, and the second terminal of the thirty-ninth resistor is connected to the second terminal of the energy storage capacitor.
[0010] According to the present invention based on the above scheme, the reset circuit further includes a sixteenth capacitor and a forty-first resistor. The first end of the sixteenth capacitor is connected to the source of the MOS transistor, the second end of the sixteenth capacitor is connected to the common terminal of the gate of the MOS transistor and the forty-first resistor, and the second end of the forty-first resistor is connected to the second end of the thirty-ninth resistor.
[0011] According to the present invention based on the above scheme, the reset circuit further includes a first diode, which is connected in parallel with the forty-first resistor.
[0012] According to the present invention based on the above scheme, the first end of the forty-first resistor is connected to the anode of the first diode, and the second end of the forty-first resistor is connected to the cathode of the first diode.
[0013] According to the present invention based on the above scheme, the reset circuit further includes a third diode, which is disposed between the forty-first resistor and the thirty-ninth resistor.
[0014] According to the present invention based on the above scheme, the anode of the third diode is connected to the second terminal of the forty-first resistor, and the cathode of the third diode is connected to the second terminal of the thirty-ninth resistor.
[0015] According to the present invention based on the above scheme, the transformer power supply circuit includes a transformer, a second diode and a seventh capacitor. The first pin of the transformer is connected to the first terminal of the seventh capacitor, the second pin of the transformer is connected to the anode of the second diode, and the cathode of the second diode is connected to the second terminal of the seventh capacitor.
[0016] According to the above-described scheme of this utility model, the first end of the seventh capacitor is connected to the first end of the sixteenth capacitor, and the second end of the seventh capacitor is connected to the second end of the forty-first resistor.
[0017] According to the above-described solution, the beneficial effects of this utility model are as follows: This utility model addresses the false lock-up phenomenon that occurs in the control chip of a small-volume power supply during rapid power-on and power-off states. It can be widely used in high-density, small-volume power supplies. The circuit is simple, effective, and low-cost. By adding a reset circuit, the power supply can be powered on normally. After the transformer power supply circuit senses the voltage of the energy storage capacitor, the reset circuit discharges the energy storage capacitor. After the power supply is powered off, the reset circuit can continue to discharge the energy storage capacitor, causing the voltage of the energy storage capacitor to quickly return to 0V, that is, the pin voltage of the control chip to quickly return to 0V, thereby achieving the reset function of the control chip and preparing for the next power-on. Attached Figure Description
[0018] Figure 1 This is the circuit schematic diagram of the present invention.
[0019] Figure 2 This is a schematic diagram of the circuit structure of this utility model. Detailed Implementation
[0020] To make the technical problems, technical solutions and beneficial effects of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments.
[0021] It should be noted that the terms "comprising" and "having," and any variations thereof, in the specification and claims of this utility model are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products, or devices. Terms such as "set up" should be interpreted broadly; for example, it can refer to a fixed connection, a detachable connection, or an integral part; it can refer to a mechanical connection or an electrical connection; it can refer to a direct connection or an indirect connection through an intermediate medium; it can refer to the internal communication of two elements or the interaction between two elements, unless otherwise expressly defined. Terms such as "upper," "lower," "left," "right," "front," "rear," and "bottom" indicate orientations or positions based on the orientations or positions shown in the accompanying drawings, and are only for ease of description and should not be construed as limiting the present technical solution.
[0022] It should be noted that existing power supply control circuits are quite complex, especially in small-sized power supplies. The control chip may experience false lock-up during rapid power-on and power-off processes, causing the power supply to malfunction. This problem severely impacts the stability and reliability of the power supply, limiting the application range of DC / DC converters.
[0023] like Figures 1-2As shown, a power control circuit addresses the false lock-up phenomenon that occurs in the control chip of a small-volume power supply during rapid power-on and power-off. It can be widely used in high-density, small-volume power supplies. The circuit is simple, effective, and low-cost. By adding a reset circuit, the power supply can be powered on normally. After the transformer power supply circuit senses the voltage of the energy storage capacitor, the reset circuit discharges the energy storage capacitor. After the power supply is powered off, the reset circuit continues to discharge the energy storage capacitor, causing its voltage to quickly return to 0V, which in turn causes the pin voltage of the control chip to quickly return to 0V. This achieves the reset function of the control chip, preparing it for the next power-on.
[0024] Specifically, the power control circuit includes a start-up resistor, a control chip, an energy storage capacitor, a reset circuit, and a transformer power supply circuit. The start-up resistor is placed between the input voltage terminal and the energy storage capacitor. The energy storage capacitor is connected to the control chip and also to the reset circuit. The reset circuit is used to discharge the energy storage capacitor. The reset circuit is connected to the transformer power supply circuit, which is used to control the opening and closing of the reset circuit.
[0025] In one embodiment, the first end of the energy storage capacitor is connected to the first pin of the control chip, and the second end of the energy storage capacitor is connected to the fifth pin of the control chip.
[0026] Specifically, such as Figure 2 As shown, the start-up resistors of the control chip U2 are R29, R21, and R30. The power supply operates in a high-voltage input state. The start-up sequence of the control chip U2 is that the input voltage terminal VIN+ is divided by R29, R21, and R30 to start the energy storage capacitor C12. However, the start-up voltage and recovery voltage of the fifth pin of the control chip U2 are significantly different. When the power supply is turned off, the voltage discharge speed of the energy storage capacitor C12 is slow, and the control chip U2 locks up and cannot be restarted, causing the power supply to malfunction.
[0027] In one embodiment, the reset circuit includes a MOSFET and a 39th resistor. The source of the MOSFET is connected to the first terminal of the energy storage capacitor and is grounded. The drain of the MOSFET is connected to the first terminal of the 39th resistor, and the second terminal of the 39th resistor is connected to the second terminal of the energy storage capacitor. When the MOSFET is in the ON state, it provides an effective discharge path to the energy storage capacitor. After the drain and source of the MOSFET are turned on, current flows through the 39th resistor from one end of the energy storage capacitor to the other, thereby discharging the energy storage capacitor. The function of the 39th resistor is to quickly dissipate the electrical energy stored in the energy storage capacitor, thereby triggering the system reset.
[0028] The reset circuit also includes a sixteenth capacitor and a forty-first resistor. The first terminal of the sixteenth capacitor is connected to the source of the MOSFET, and the second terminal is connected to the common terminal of the MOSFET gate and the forty-first resistor. The second terminal of the forty-first resistor is connected to the second terminal of the thirty-ninth resistor. The voltage at the MOSFET gate is the same as the voltage at the forty-first resistor. By adjusting the MOSFET gate voltage, the on / off state of the MOSFET's source and drain can be controlled. When the gate voltage reaches a certain threshold, the MOSFET will conduct; when the gate voltage is below this threshold, the MOSFET will be off.
[0029] The reset circuit also includes a first diode connected in parallel with a forty-first resistor. The first terminal of the forty-first resistor is connected to the anode of the first diode, and the second terminal of the forty-first resistor is connected to the cathode of the first diode. The primary function of the first diode is to provide an additional current path to protect other components in the circuit from damage caused by excessive or reverse voltage. When the voltage in the circuit exceeds the diode's threshold voltage, the diode will conduct, allowing current to flow and be shunted to ground or other low-potential points. This prevents component damage due to excessive voltage.
[0030] The reset circuit also includes a third diode, positioned between resistors forty-first and thirty-ninth. The anode of the third diode is connected to the second terminal of resistor forty-first, and the cathode is connected to the second terminal of resistor thirty-ninth. The primary function of the third diode is as a voltage clamping element to limit voltage fluctuations in the circuit. When the voltage in the circuit exceeds the breakdown voltage of the third diode, it will conduct, clamping the voltage to a relatively low level. This protects other components in the circuit from damage caused by voltage fluctuations and ensures the stable operation of the reset circuit.
[0031] In one embodiment, the transformer power supply circuit includes a transformer, a second diode, and a seventh capacitor. The first pin of the transformer is connected to the first terminal of the seventh capacitor, the second pin of the transformer is connected to the anode of the second diode, and the cathode of the second diode is connected to the second terminal of the seventh capacitor.
[0032] The second diode here acts as a half-wave rectifier, allowing only the positive half-cycle (or negative half-cycle, depending on the diode's polarity) of the alternating current to pass through and converting it to direct current. When the positive half-cycle of the alternating current arrives, the second diode conducts, allowing current to flow from the second pin of the transformer to the seventh capacitor; while in the negative half-cycle, the diode is cut off, preventing current from flowing.
[0033] The seventh capacitor acts as a filter capacitor, and its first terminal (the one connected to the first pin of the transformer) and second terminal (the one connected to the cathode of the second diode) form a DC voltage output. This capacitor can smooth the rectified DC current, reduce voltage fluctuations, and provide a stable DC power supply for subsequent circuits.
[0034] The first terminal of the seventh capacitor is connected to the first terminal of the sixteenth capacitor, and the second terminal of the seventh capacitor is connected to the second terminal of the forty-first resistor. The DC voltage output by the seventh capacitor is applied to the gate of the MOSFET through the forty-first resistor. If the voltage reaches or exceeds the threshold voltage of the MOSFET, the MOSFET will conduct; conversely, if the voltage is below the threshold voltage, the MOSFET will be turned off. By controlling the DC voltage output from the transformer power supply circuit, the conduction state of the MOSFET can be indirectly controlled, thereby achieving control and adjustment of the reset circuit.
[0035] It should be understood that those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims.
[0036] The present utility model patent has been described above with reference to the accompanying drawings. Obviously, the implementation of the present utility model patent is not limited to the above-described manner. Any improvements made by adopting the inventive concept and technical solution of the present utility model patent, or the direct application of the inventive concept and technical solution of the present utility model patent to other occasions without modification, are all within the protection scope of the present utility model.
Claims
1. A power control circuit, characterized by comprising: The application relates to a power-on resistor, a control chip, an energy storage capacitor, a reset circuit and a transformer power supply circuit, wherein the power-on resistor is arranged between an input voltage end and the energy storage capacitor; the energy storage capacitor is connected with the control chip; the energy storage capacitor is also connected with the reset circuit; the reset circuit is used for discharging the energy storage capacitor; the reset circuit is connected with the transformer power supply circuit; and the transformer power supply circuit is used for controlling the opening and closing of the reset circuit.
2. A power control circuit according to claim 1, wherein The first end of the energy storage capacitor is connected with the first pin of the control chip, and the second end of the energy storage capacitor is connected with the fifth pin of the control chip.
3. A power control circuit according to claim 2, wherein The reset circuit comprises a MOS tube and a thirty-ninth resistor; the source of the MOS tube is connected with the first end of the energy storage capacitor, and the source of the MOS tube is grounded; the drain of the MOS tube is connected with the first end of the thirty-ninth resistor; and the second end of the thirty-ninth resistor is connected with the second end of the energy storage capacitor.
4. A power control circuit according to claim 3, wherein The reset circuit further comprises a sixteenth capacitor and a forty-first resistor; the first end of the sixteenth capacitor is connected with the source of the MOS tube; the second end of the sixteenth capacitor is connected with the gate of the MOS tube and the common end of the forty-first resistor; and the second end of the forty-first resistor is connected with the second end of the thirty-ninth resistor.
5. A power control circuit according to claim 4, wherein The reset circuit further comprises a first diode which is connected in parallel with the forty-first resistor.
6. A power control circuit according to claim 5, wherein The first end of the forty-first resistor is connected with the anode of the first diode, and the second end of the forty-first resistor is connected with the cathode of the first diode.
7. A power control circuit according to claim 4, wherein The reset circuit further comprises a third diode which is arranged between the forty-first resistor and the thirty-ninth resistor.
8. A power control circuit according to claim 7, wherein The anode of the third diode is connected with the second end of the forty-first resistor, and the cathode of the third diode is connected with the second end of the thirty-ninth resistor.
9. A power control circuit according to claim 4, 5, 6, 7 or 8, characterised in that, The transformer power supply circuit comprises a transformer, a second diode and a seventh capacitor; the first pin of the transformer is connected with the first end of the seventh capacitor; the second pin of the transformer is connected with the anode of the second diode; and the cathode of the second diode is connected with the second end of the seventh capacitor.
10. A power control circuit according to claim 9, wherein The first end of the seventh capacitor is connected with the first end of the sixteenth capacitor, and the second end of the seventh capacitor is connected with the second end of the forty-first resistor.