A power supply protection circuit and a power supply system
By working in concert with voltage sampling, filtering, and logic control units, the problem of slow response speed and low accuracy in existing power protection circuits is solved, achieving fast and reliable power protection. It is suitable for various power systems, especially in AC output application scenarios.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- JIANGSU TRINATEC ELECTRIC CO LTD
- Filing Date
- 2025-08-15
- Publication Date
- 2026-07-24
AI Technical Summary
Existing power protection circuits have slow response speed, low protection accuracy, are easily affected by power noise, are complex to design and costly, and cannot meet the high requirements of modern electronic equipment for power stability and reliability.
The system employs a voltage sampling unit, a filtering unit, a logic control unit, and a power control unit working in concert. Through voltage sampling, filtering, and logic control, it generates a fast-response control signal to control the power management unit for protection. The system uses a modular design and a transistor logic control unit with a specific connection method for accurate judgment.
It achieves fast and reliable power protection, improves the sensitivity and reliability of the circuit, reduces costs, is highly adaptable, and is suitable for a variety of power systems, especially in AC output applications.
Smart Images
Figure CN224555191U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of power supply protection, and in particular to a power supply protection circuit and power supply system. Background Technology
[0002] In modern electronic devices, power protection is a crucial element in ensuring the safe and stable operation of the system. Existing power protection technologies typically employ simple overvoltage or undervoltage detection circuits. While this method can protect the power system to some extent, it suffers from problems such as slow response speed and low protection accuracy.
[0003] Traditional power protection circuits often use fixed threshold values to detect voltage anomalies, a method that is difficult to adapt to complex and variable power environments. For example, in situations with large power grid fluctuations, fixed threshold values may lead to frequent false triggers or untimely protection, affecting the normal operation of the system.
[0004] Furthermore, existing power protection circuits typically lack effective signal processing capabilities, making them susceptible to power supply noise and interference. This design flaw can cause protection circuits to misjudge the power supply status, triggering unnecessary protection actions or missing the opportunity when true protection is needed.
[0005] Another common problem is that many power protection circuits are overly complex, using a large number of discrete components or expensive application-specific integrated circuits (ASICs). This not only increases the size and cost of the circuit but also reduces the reliability and maintainability of the system.
[0006] These problems in existing technologies result in ineffective power protection, failing to meet the high requirements of modern electronic devices for power stability and reliability. Particularly in critical applications such as medical equipment and industrial control systems, these issues can lead to serious safety hazards and economic losses. Utility Model Content
[0007] The purpose of this invention is to provide a power protection circuit to solve the technical problems of unreliable power protection and slow response speed in the prior art.
[0008] To achieve the above objectives, the present invention adopts the following technical solution:
[0009] This utility model provides a power protection circuit, including: a voltage sampling unit for acquiring power supply voltage;
[0010] A filtering unit, electrically connected to the voltage sampling unit, is used to filter the acquired voltage signal;
[0011] A logic control unit, electrically connected to the filtering unit, is used to generate a control signal based on the filtered voltage signal.
[0012] The power control unit is electrically connected to the logic control unit and has a control port for controlling the PWM output according to the control signal.
[0013] The power management unit is electrically connected to the power control unit and is used to control the power supply of the system according to the PWM output state of the power control unit.
[0014] Furthermore, the voltage sampling unit includes a first resistor and a second resistor connected in series, wherein: one end of the first resistor is connected to the positive terminal of the power supply, and the other end is connected to one end of the second resistor; the other end of the second resistor is grounded.
[0015] Specifically, the resistance of the first resistor is 10-20 times that of the second resistor.
[0016] Furthermore, the filtering unit includes a third resistor and a first capacitor connected in series, wherein: one end of the third resistor is connected to the connection point of the first resistor and the second resistor; the other end of the third resistor is connected to one end of the first capacitor and is connected to the logic control unit; and the other end of the first capacitor is grounded.
[0017] Specifically, the resistance value of the third resistor is in the range of 5KΩ to 20KΩ; the capacitance value of the first capacitor is in the range of 50nF to 200nF.
[0018] Furthermore, the logic control unit includes a first transistor, a second transistor, and a third transistor, wherein: the collector of the first transistor is electrically connected to the base of the second transistor; the collector of the second transistor is electrically connected to the base of the third transistor; the emitter of the first transistor is electrically connected to the positive terminal of the power supply; the emitter of the second transistor is grounded; the collector of the third transistor is electrically connected to the control port of the power control unit, and its emitter is grounded.
[0019] Furthermore, the logic control unit also includes a diode, a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor, and an eighth resistor, wherein: the anode of the diode is electrically connected to the filter unit, and the cathode is electrically connected to one end of the fourth resistor; the other end of the fourth resistor is electrically connected to the base of the first transistor and one end of the fifth resistor; the other end of the fifth resistor is electrically connected to the emitter of the first transistor; the sixth resistor is connected between the collector of the first transistor and the base of the second transistor; one end of the seventh resistor is electrically connected to the collector of the second transistor and the base of the third transistor, and the other end is electrically connected to the positive terminal of the power supply; one end of the eighth resistor is electrically connected to the collector of the second transistor and the base of the third transistor, and the other end is grounded.
[0020] Furthermore, the power management unit includes a ninth resistor, a second capacitor, and a load connected in parallel, wherein:
[0021] The ninth resistor, the second capacitor, and the load are all connected in parallel between the control port of the power control unit and ground.
[0022] Furthermore, the control port of the power control unit is a COM port.
[0023] This utility model also provides a power supply system, including the power protection circuit, power supply and load as described above; the power supply is electrically connected to the voltage sampling unit, and the load is electrically connected to the power management unit.
[0024] The power protection circuit provided by this invention monitors the power supply voltage in real time through a voltage sampling unit. After filtering by a filtering unit, the signal is processed by a logic control unit to quickly generate a control signal. This signal is then controlled by the PWM output of the power control unit to control the power management unit, achieving fast and reliable protection of the power system. The circuit has a simple structure, fast response speed, and effectively prevents damage to the system caused by abnormal power supply voltage. Furthermore, due to its modular design, the circuit has good scalability and adaptability, and can be applied to various types of power systems.
[0025] Specifically, this invention employs a logic control unit composed of three transistors, achieving accurate judgment and rapid response to voltage signals through a specific connection method. This design not only improves circuit reliability but also reduces cost. Furthermore, the use of a Com port to control the PWM output further enhances the circuit's flexibility and versatility. In addition, the specific design of the voltage sampling and filtering units ensures accurate voltage signal acquisition and effective filtering, further improving the accuracy and stability of the entire protection system. Finally, the addition of an inverter unit allows this protection circuit to better adapt to different power supply requirements, especially in applications requiring AC power output. Attached Figure Description
[0026] Figure 1 This is a block diagram of the power protection circuit control in one embodiment of the present invention;
[0027] Figure 2 This is a schematic diagram of a power protection circuit in one embodiment of the present invention. Detailed Implementation
[0028] The technical solution of this utility model will be described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that the described embodiments are only used to explain the technical principles of this utility model, and not to limit its scope of protection. Those skilled in the art should understand that various transformations, modifications, or equivalent substitutions can be made to these embodiments without departing from the spirit and scope of this utility model. All such transformations, modifications, or equivalent substitutions should be considered to fall within the scope of protection defined by the claims of this utility model.
[0029] like Figure 1 As shown, the power protection circuit provided by this utility model includes a voltage sampling unit, a filtering unit, a logic control unit, a power control unit, and a power management unit. These units work together to form a complete power protection system.
[0030] The voltage sampling unit is used to acquire the power supply voltage. For example... Figure 2 As shown, the voltage sampling unit includes a first resistor R1 and a second resistor R2 connected in series. Specifically, one end of the first resistor R1 is connected to BAT+ (positive power supply), and the other end is connected to the second resistor R2 and one end of the third resistor R3 in the subsequent filtering circuit. The other end of the second resistor R2 is grounded. In this embodiment, the resistance of the first resistor R1 is 10-20 times the resistance of the second resistor R2. For example, the first resistor R1 can be a 100KΩ resistor, and the second resistor R2 can be a 10KΩ resistor, forming an 11:1 voltage division ratio. This configuration can convert a higher power supply voltage (e.g., 48V) to a lower voltage (e.g., around 4V), facilitating subsequent circuit processing.
[0031] In a specific example, the filtering unit is electrically connected to the voltage sampling unit and is used to filter the acquired voltage signal. For example... Figure 2 As shown, the filter unit includes a third resistor R3 and a first capacitor C1. One end of the third resistor R3 is connected to the common terminal of the first resistor R1 and the second resistor R2, and the other end is connected to the anode of the diode U1 and one end of the first capacitor C1. The other end of the first capacitor C1 is grounded. The resistance value of the third resistor ranges from 5KΩ to 20KΩ, and the capacitance value of the first capacitor ranges from 50nF to 200nF. In this embodiment, the third resistor R3 can be a 10KΩ resistor, and the first capacitor C1 can be a 100nF capacitor. This RC low-pass filter circuit has a cutoff frequency of approximately 160kHz and can effectively filter out high-frequency noise in the power supply.
[0032] In this embodiment, the logic control unit is electrically connected to the filtering unit and is used to generate a control signal based on the filtered voltage signal. Please continue to refer to... Figure 2The logic control unit includes a first transistor Q1, a second transistor Q2 and a third transistor Q3, and also includes a diode U1, a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, a seventh resistor R7 and an eighth resistor R8.
[0033] Specifically, the anode of diode U1 is connected to the common terminal of the third resistor R3 and the first capacitor C1, and the cathode is connected to one end of the fourth resistor R4. The other end of the fourth resistor R4 is connected to the base of the first transistor Q1 and one end of the fifth resistor R5. The emitter of the first transistor Q1 is connected to Vcc and the other end of the fifth resistor R5. The collector of the first transistor Q1 is connected to one end of the sixth resistor R6. The other end of the sixth resistor R6 is connected to the base of the second transistor Q2. The collector of the second transistor Q2 is connected to one end of the seventh resistor R7 and the eighth resistor R8, as well as the base of the third transistor Q3. The emitter of the second transistor Q2 is grounded. The other end of the seventh resistor R7 is connected to BAT+, and the other end of the eighth resistor R8 is grounded. The collector of the third transistor Q3 is connected to the Com port, and its emitter is grounded.
[0034] The working principle of the logic control unit is as follows: When the battery voltage is normal, the first transistor Q1 is turned on, the second transistor Q2 is turned off, and the third transistor Q3 is also turned off, and the Com port remains at a high level; when the battery voltage drops below the set threshold, the first transistor Q1 is turned off, the second transistor Q2 is turned on, which in turn turns on the third transistor Q3, pulling the Com port low and triggering the protection action.
[0035] In this embodiment, the power control unit is electrically connected to the logic control unit and has a control port (Com) for controlling the PWM output according to the control signal. In this embodiment, the power control unit can use a dedicated PWM controller chip, such as the UC3842. The Com port of this chip is connected to the collector of the third transistor Q3. When the Com port voltage is pulled low, the PWM output is turned off; when the Com port voltage remains high, the PWM output is normal.
[0036] In one specific example, the power management unit is electrically connected to the power control unit and is used to control the power supply to the system based on the PWM output state of the power control unit. The power management unit may include a ninth resistor R9 connected in parallel between Com and ground, a second capacitor C2, and a load U2. This configuration can provide a stable control signal and a reference voltage for subsequent power management circuitry.
[0037] In practical applications, the power protection circuit of this invention can be adjusted and optimized according to specific needs. For example, the resistance ratio of the first resistor R1 and the second resistor R2 can be adjusted to adapt to different input voltage ranges. By changing the values of the third resistor R3 and the first capacitor C1, the filtering characteristics can be adjusted. In environments with strong electromagnetic interference, the first capacitor C1 can be increased to provide better filtering effects and improve the circuit's anti-interference capability.
[0038] For logic control units, transistors with different characteristics can be selected according to actual needs. For applications requiring fast response, high-frequency transistors can be used to improve circuit response speed and trigger protection mechanisms more quickly. In applications with large voltage fluctuations, the resistance values of the fourth resistor R4 and the fifth resistor R5 can be adjusted to change the conduction threshold of the first transistor Q1, thereby optimizing the protection trigger point.
[0039] Furthermore, by adjusting the resistance ratio of the seventh resistor R7 and the eighth resistor R8, the operating points of the second transistor Q2 and the third transistor Q3 can be finely adjusted, so that the protection circuit can maintain good sensitivity under different voltage conditions.
[0040] In another embodiment of this utility model, a power supply system is provided. This power supply system includes the power protection circuit, power supply, and load described above.
[0041] Specifically, the power supply is electrically connected to the voltage sampling unit in the power protection circuit. In this embodiment, the power supply can be a 24V lithium battery pack. The voltage sampling unit is directly connected to the positive terminal of the battery pack through a voltage divider circuit composed of a first resistor R1 and a second resistor R2 to monitor the battery voltage in real time.
[0042] The load is electrically connected to the power management unit in the power protection circuit. In this embodiment, the load can be a 48V / 1kW DC-DC converter. The power management unit directly controls the enable terminal of the DC-DC converter through its output terminal, and can immediately cut off the power supply to the load when an abnormal battery voltage is detected.
[0043] This configuration ensures the power safety of the entire system. When the battery voltage drops below a preset threshold, the power protection circuit responds quickly, cutting off power to the load through the power management unit, thereby protecting the battery from over-discharge and also protecting the load equipment from low-voltage damage. Furthermore, this system design offers excellent scalability, allowing for easy replacement of different types of power supplies or loads as needed without significant modifications to the protection circuitry itself.
[0044] The power protection circuit provided by this utility model has the following beneficial effects:
[0045] First, by employing a multi-level protection structure (voltage sampling, filtering, logic control, power control, and power management), comprehensive monitoring and rapid response of the power supply voltage are achieved. This design significantly improves the reliability and sensitivity of power supply protection, enabling it to react in the early stages of power supply voltage anomalies and effectively preventing damage to the system caused by such anomalies.
[0046] Secondly, a logic control unit composed of three transistors, connected in a specific manner, enables precise judgment and rapid response to voltage signals. This design not only improves circuit reliability but also reduces cost, making the protection circuit suitable for various types of power supply systems. Furthermore, the use of a Com port to control the PWM output further enhances the circuit's flexibility and versatility, making it easy to integrate with various power management chips.
[0047] Furthermore, the power protection circuit of this invention has a simple structure, is easy to implement and maintain, and has good scalability. By adding an inverter unit, this protection circuit can better adapt to different power requirements, especially in applications requiring AC output. This design provides strong protection for the safety and reliability of the power system and has broad application prospects.
[0048] Finally, the power protection circuit of this invention adopts a modular design with clear interfaces between functional units, facilitating customization and optimization according to actual needs. This flexibility allows the circuit to adapt to various application scenarios, from simple household power supplies to complex industrial power systems, providing strong protection for the safe and stable operation of power systems. Furthermore, due to its simple yet effective design, the circuit is easily integrated into various power management systems, significantly improving the reliability and safety of the entire system and reducing the risk of equipment damage caused by power problems.
[0049] This utility model has been described in detail through the above specific embodiments. However, it should be understood that the above content is illustrative only and is not intended to limit the scope of this utility model. Those skilled in the art can make various modifications and variations to this utility model according to specific application scenarios and actual needs without departing from the spirit and scope of this utility model, and such modifications and variations are all within the protection scope of this utility model.
Claims
1. A power supply protection circuit, characterized in that, include: Voltage sampling unit, used to collect power supply voltage; A filtering unit, electrically connected to the voltage sampling unit, is used to filter the acquired voltage signal; A logic control unit, electrically connected to the filtering unit, is used to generate a control signal based on the filtered voltage signal. The power control unit is electrically connected to the logic control unit and has a control port for controlling the PWM output according to the control signal. The power management unit is electrically connected to the power control unit and is used to control the power supply of the system according to the PWM output state of the power control unit.
2. The power protection circuit according to claim 1, characterized in that, The voltage sampling unit includes a first resistor and a second resistor connected in series, wherein: One end of the first resistor is connected to the positive terminal of the power supply, and the other end is connected to one end of the second resistor; The other end of the second resistor is grounded.
3. The power protection circuit according to claim 2, characterized in that, The resistance of the first resistor is 10-20 times that of the second resistor.
4. The power protection circuit according to claim 2, characterized in that, The filtering unit includes a third resistor and a first capacitor connected in series, wherein: One end of the third resistor is connected to the connection point of the first resistor and the second resistor; The other end of the third resistor is connected to one end of the first capacitor and is also connected to the logic control unit. The other end of the first capacitor is grounded.
5. The power protection circuit according to claim 4, characterized in that, The resistance value of the third resistor is in the range of 5KΩ to 20KΩ; the capacitance value of the first capacitor is in the range of 50nF to 200nF.
6. The power protection circuit according to claim 1, characterized in that, The logic control unit includes a first transistor, a second transistor, and a third transistor, wherein: The collector of the first transistor is electrically connected to the base of the second transistor; The collector of the second transistor is electrically connected to the base of the third transistor; The emitter of the first transistor is electrically connected to the positive terminal of the power supply; The emitter of the second transistor is grounded; The collector of the third transistor is electrically connected to the control port of the power control unit, and the emitter is grounded.
7. The power protection circuit according to claim 6, characterized in that, The logic control unit further includes a diode, a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor, and an eighth resistor, wherein: The anode of the diode is electrically connected to the filter unit, and the cathode is electrically connected to one end of the fourth resistor; The other end of the fourth resistor is electrically connected to the base of the first transistor and one end of the fifth resistor; The other end of the fifth resistor is electrically connected to the emitter of the first transistor; The sixth resistor is connected between the collector of the first transistor and the base of the second transistor; One end of the seventh resistor is electrically connected to the collector of the second transistor and the base of the third transistor, and the other end is electrically connected to the positive terminal of the power supply. One end of the eighth resistor is electrically connected to the collector of the second transistor and the base of the third transistor, and the other end is grounded.
8. The power protection circuit according to claim 1, characterized in that, The power management unit includes a ninth resistor, a second capacitor, and a load connected in parallel, wherein: The ninth resistor, the second capacitor, and the load are all connected in parallel between the control port of the power control unit and ground.
9. The power protection circuit according to claim 1, characterized in that, The control port of the power control unit is the Com port.
10. A power supply system, characterized in that, include: Power protection circuit as described in any one of claims 1 to 9; The power supply is electrically connected to the voltage sampling unit; The load is electrically connected to the power management unit.