A power supply protection circuit

Abstract

The utility model relates to power supply circuit technical field, concretely relates to a power protection circuit, including input port, output port and ground terminal, the power protection circuit still includes overcurrent protection module, overtemperature protection module, undervoltage protection module, triode Q1 and resistance R4, one end of resistance R4 is connected with input port, the other end of resistance R4 is connected with triode Q1's base, triode Q1's collector is connected with input port, triode Q1's emitter is connected with output port, the utility model discloses through integrated overcurrent protection module, overtemperature protection module and undervoltage protection module, can when the current of load is too big, the situation that input port exists under voltage or when temperature is too high, make triode Q1 base voltage reduction, lead to triode Q1 disconnect, thereby cut off the output to load, effectively play the role of protection.

Description

Technical Field

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

[0002] In modern electronic devices, the power supply circuit is a core component, and its stability and reliability directly affect the normal operation of the equipment. Whether it's consumer electronics, industrial control equipment, or communication base stations, all rely on power supply circuits to provide stable power. However, in practical applications, power supply circuits are highly susceptible to abnormal conditions such as overcurrent, overtemperature, and undervoltage. Overcurrent may damage components due to excessive current; overtemperature can accelerate component aging and even cause serious safety accidents such as fires; undervoltage can cause equipment to malfunction and result in data loss.

[0003] Although power supply circuits play a crucial role in various devices, most power supply circuit designs on the market today have relatively weak protection against overcurrent, overtemperature, and undervoltage. Some power supply circuits only have a single protection function and lack a comprehensive protection mechanism against multiple abnormal conditions. Utility Model Content

[0004] The purpose of this invention is to address the aforementioned shortcomings in the prior art by providing a power protection circuit.

[0005] The purpose of this utility model is achieved through the following technical solution: a power protection circuit, including an input port, an output port and a ground port; the power protection circuit also includes an overcurrent protection module, an overtemperature protection module, an undervoltage protection module, a transistor Q1 and a resistor R4; One end of resistor R4 is connected to the input port; the other end of resistor R4 is connected to the base of transistor Q1; the collector of transistor Q1 is connected to the input port; and the emitter of transistor Q1 is connected to the output port. The overcurrent protection module, overtemperature protection module, and undervoltage protection module are respectively connected to the base of transistor Q1.

[0006] The present invention is further configured such that the overcurrent protection module includes a resistor R5 and a transistor Q2; one end of the resistor R5 is connected to the emitter of the transistor Q1; the other end of the resistor R5 is connected to the output port; the base of the transistor Q2 is connected to the emitter of the transistor Q1; the emitter of the transistor Q2 is connected to the output port; and the collector of the transistor Q2 is connected to the base of the transistor Q1.

[0007] The present invention is further configured such that the power protection circuit also includes a light-emitting diode D1; the light-emitting diode D1 is disposed between one end of the resistor R5 and the emitter of the transistor Q1.

[0008] The present invention is further configured such that the overcurrent protection module also includes a light-emitting diode D2; the light-emitting diode D2 is disposed between the emitter and the output port of the transistor Q2.

[0009] The present invention is further configured such that the over-temperature protection module includes a thermistor, a resistor R3, and a transistor Q3; one end of the thermistor is connected to the input port; the other end of the thermistor is connected to the ground port through the resistor R3; the other end of the thermistor is connected to the base of the transistor Q3; the collector of the transistor Q3 is connected to the base of the transistor Q1; and the emitter of the transistor Q3 is grounded.

[0010] The present invention is further configured such that the over-temperature protection module also includes a light-emitting diode D3; the light-emitting diode D3 is disposed between the emitter of the transistor Q3 and the ground port.

[0011] The present invention is further configured such that the undervoltage protection module includes a resistor R1, a resistor R2, and a transistor Q4; one end of the resistor R1 is connected to the input port; the other end of the resistor R1 is connected to the ground port through the resistor R2; the other end of the resistor R1 is connected to the base of the transistor Q4; the collector of the transistor Q4 is connected to the base of the transistor Q1; and the emitter of the transistor Q4 is grounded.

[0012] The present invention is further configured such that the undervoltage protection module also includes a light-emitting diode D4; the light-emitting diode D4 is disposed between the emitter of transistor Q4 and the ground port; the transistor Q4 is a PNP transistor.

[0013] The present invention is further configured such that both transistor Q1 and transistor Q2 are NPN transistors.

[0014] The present invention is further configured such that the transistor Q3 is an NPN transistor.

[0015] The beneficial effects of this utility model are as follows: By integrating an overcurrent protection module, an overtemperature protection module, and an undervoltage protection module, this utility model can reduce the voltage at the base of transistor Q1 when the load current is too high, when there is an undervoltage at the input port, or when the temperature is too high, causing transistor Q1 to disconnect and thus cut off the output to the load, effectively playing a protective role. Attached Figure Description

[0016] Figure 1 This is the circuit schematic diagram of this utility model; Among them: 1. Input port; 2. Grounding port; 3. Output port; 4. Thermistor. Detailed Implementation

[0017] The present invention will be further described in conjunction with the following embodiments.

[0018] Depend on Figure 1 As can be seen, the power protection circuit described in this embodiment includes an input port 1, an output port 3, and a ground port 2; the power protection circuit also includes an overcurrent protection module, an overtemperature protection module, an undervoltage protection module, a transistor Q1, and a resistor R4; One end of the resistor R4 is connected to the input port 1; the other end of the resistor R4 is connected to the base of the transistor Q1; the collector of the transistor Q1 is connected to the input port 1; and the emitter of the transistor Q1 is connected to the output port 3. The overcurrent protection module, overtemperature protection module, and undervoltage protection module are respectively connected to the base of transistor Q1.

[0019] Specifically, in the power protection circuit described in this embodiment, when the current, voltage, and temperature are normal, the power supply at the input terminal, through resistor R4, causes transistor Q1 to be in a conducting state. At this time, input port 1, transistor Q1, and output port 3 are in a closed circuit, and the power supply at the input terminal can normally supply power to the load. When the load current is too large, there is an undervoltage at input port 1, or the temperature is too high, the voltage at the base of transistor Q1 decreases, causing transistor Q1 to turn off, thereby cutting off the output to the load and playing a protective role.

[0020] This embodiment integrates an overcurrent protection module, an overtemperature protection module, and an undervoltage protection module. When the load current is too high, there is an undervoltage at input port 1, or the temperature is too high, the voltage at the base of transistor Q1 decreases, causing transistor Q1 to disconnect and thus cutting off the output to the load, effectively providing protection.

[0021] This embodiment of a power supply protection circuit includes an overcurrent protection module comprising a resistor R5 and a transistor Q2. One end of the resistor R5 is connected to the emitter of transistor Q1; the other end of the resistor R5 is connected to output port 3; the base of transistor Q2 is connected to the emitter of transistor Q1; the emitter of transistor Q2 is connected to output port 3; and the collector of transistor Q2 is connected to the base of transistor Q1. In this embodiment of the power supply protection circuit, both transistors Q1 and Q2 are NPN transistors.

[0022] Specifically, in the power protection circuit described in this embodiment, when the load current is normal, the power supply at the input terminal, through resistor R4, causes transistor Q1 to be in a conducting state. At this time, input port 1, transistor Q1, resistor R5, and output port 3 are in a closed circuit. When the current is normal, the voltage at the base of transistor Q2 is insufficient to turn it on, so transistor Q2 remains in an off state, which does not affect the conduction of transistor Q1. The power supply at the input terminal can supply power to the load normally. When the load current is too high, the voltage at the base of transistor Q2 becomes too high, causing transistor Q2 to conduct. This reduces the voltage at the base of transistor Q1, causing transistor Q1 to turn off, thus cutting off the output to the load and providing overcurrent protection.

[0023] This embodiment describes a power protection circuit, which further includes a light-emitting diode (LED) D1. The LED D1 is positioned between one end of resistor R5 and the emitter of transistor Q1. Specifically, with the above configuration, when transistor Q1 is in a conducting state, i.e., when the power supply at the input terminal can normally supply power to the load, the LED D1 illuminates, thereby reminding the user that the circuit is working normally.

[0024] The power supply protection circuit described in this embodiment further includes an overcurrent protection module with a light-emitting diode (LED) D2. The LED D2 is positioned between the emitter of transistor Q2 and the output port 3. Specifically, with this configuration, when the load current is too high, the voltage at the base of transistor Q2 becomes too high, causing transistor Q2 to conduct and the LED D2 to emit light, thus alerting the user to an overcurrent situation.

[0025] This embodiment of a power supply protection circuit includes an over-temperature protection module comprising a thermistor 4, a resistor R3, and a transistor Q3. One end of the thermistor 4 is connected to input port 1; the other end of the thermistor 4 is connected to ground port 2 via resistor R3; the other end of the thermistor 4 is connected to the base of transistor Q3; the collector of transistor Q3 is connected to the base of transistor Q1; and the emitter of transistor Q3 is grounded. In this embodiment of the power supply protection circuit, transistor Q3 is an NPN transistor.

[0026] Specifically, in the power protection circuit described in this embodiment, when the temperature is too high, the resistance value of the thermistor 4 decreases and the voltage of the voltage divider resistor R3 increases, causing the transistor Q3 to conduct, thereby reducing the voltage at the base of the transistor Q1 and causing the transistor Q1 to turn off, thus cutting off the output to the load and playing the role of over-temperature protection.

[0027] The power supply protection circuit described in this embodiment further includes an over-temperature protection module, which is a light-emitting diode (LED) D3. The LED D3 is positioned between the emitter of transistor Q3 and the ground port 2. Specifically, with this configuration, when the temperature is too high, the resistance of the thermistor 4 decreases, the voltage across the voltage divider resistor R3 increases, causing transistor Q3 to conduct and the LED D3 to illuminate, thus alerting the user that the circuit is overheating.

[0028] This embodiment describes a power protection circuit, wherein the undervoltage protection module includes resistors R1 and R2 and a transistor Q4; one end of resistor R1 is connected to input port 1; the other end of resistor R1 is connected to ground port 2 via resistor R2; the other end of resistor R1 is connected to the base of transistor Q4; the collector of transistor Q4 is connected to the base of transistor Q1; the emitter of transistor Q4 is grounded; and transistor Q4 is a PNP transistor.

[0029] Specifically, in the power protection circuit described in this embodiment, when the voltage is normal, the voltage across resistor R2 is relatively high. Since transistor Q4 is a PNP transistor, the high voltage across resistor R2 keeps transistor Q4 in an off state. When the voltage at input port 1 is low and undervoltage occurs, the voltage across resistor R2 decreases, causing transistor Q3 to conduct. This reduces the voltage at the base of transistor Q1, causing transistor Q1 to disconnect, thus cutting off the output to the load and providing undervoltage protection.

[0030] The power protection circuit described in this embodiment includes an undervoltage protection module that further includes a light-emitting diode (LED) D4. The LED D4 is located between the emitter of transistor Q4 and the ground port 2. Specifically, with this configuration, when the voltage at input port 1 is low and undervoltage occurs, the voltage across resistor R2 decreases, causing transistor Q3 to conduct and LED D4 to illuminate, thus alerting the user to the undervoltage condition.

[0031] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit the scope of protection of this utility model. Although this utility model has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of this utility model without departing from the essence and scope of the technical solutions of this utility model.

Claims

1. A power supply protection circuit, characterized in that: It includes an input port (1), an output port (3), and a ground port (2); the power protection circuit also includes an overcurrent protection module, an overtemperature protection module, an undervoltage protection module, a transistor Q1, and a resistor R4; One end of the resistor R4 is connected to the input port (1); the other end of the resistor R4 is connected to the base of the transistor Q1; the collector of the transistor Q1 is connected to the input port (1); and the emitter of the transistor Q1 is connected to the output port (3). The overcurrent protection module, overtemperature protection module, and undervoltage protection module are respectively connected to the base of transistor Q1.

2. A power supply protection circuit according to claim 1, characterized in that: The overcurrent protection module includes a resistor R5 and a transistor Q2; one end of the resistor R5 is connected to the emitter of the transistor Q1; the other end of the resistor R5 is connected to the output port (3); the base of the transistor Q2 is connected to the emitter of the transistor Q1; the emitter of the transistor Q2 is connected to the output port (3); and the collector of the transistor Q2 is connected to the base of the transistor Q1.

3. A power supply protection circuit according to claim 2, characterised in that: The power protection circuit also includes a light-emitting diode D1; the light-emitting diode D1 is located between one end of the resistor R5 and the emitter of the transistor Q1.

4. A power supply protection circuit according to claim 2, wherein: The overcurrent protection module also includes a light-emitting diode D2; the light-emitting diode D2 is located between the emitter of transistor Q2 and the output port (3).

5. The power supply protection circuit of claim 1, wherein: The over-temperature protection module includes a thermistor (4), a resistor R3, and a transistor Q3; one end of the thermistor (4) is connected to the input port (1); the other end of the thermistor (4) is connected to the ground port (2) through the resistor R3; the other end of the thermistor (4) is connected to the base of the transistor Q3; the collector of the transistor Q3 is connected to the base of the transistor Q1; and the emitter of the transistor Q3 is grounded.

6. A power protection circuit according to claim 5, characterized in that: The over-temperature protection module also includes a light-emitting diode D3; the light-emitting diode D3 is located between the emitter of transistor Q3 and the ground port (2).

7. A power supply protection circuit according to claim 1, characterized in that: The undervoltage protection module includes resistors R1 and R2 and transistor Q4; one end of resistor R1 is connected to the input port (1); the other end of resistor R1 is connected to the ground port (2) through resistor R2; the other end of resistor R1 is connected to the base of transistor Q4; the collector of transistor Q4 is connected to the base of transistor Q1; and the emitter of transistor Q4 is grounded.

8. A power protection circuit according to claim 7, characterized in that: The undervoltage protection module also includes a light-emitting diode D4; the light-emitting diode D4 is located between the emitter of transistor Q4 and the ground port (2); the transistor Q4 is a PNP transistor.

9. A power supply protection circuit according to claim 2, wherein: Both transistors Q1 and Q2 are NPN transistors.

10. A power supply protection circuit according to claim 5, wherein: The transistor Q3 is an NPN transistor.

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