Over-temperature alarm circuit

Abstract

The utility model discloses an over-temperature alarm circuit, which comprises a power supply circuit, and is characterized by also comprising a comparison circuit connected with the power supply circuit, a sensor circuit connected with the comparison circuit and used for detecting the current temperature, and a control circuit connected with the comparison circuit, when the control circuit detects that the output of the comparison circuit is low, the triode Q2 cannot output, and when the control circuit detects that the output of the comparison circuit is high, the over-temperature is indicated, and the output is low after the conversion of the triode Q2, so that the buzzer and the indicator lamp work, the over-temperature alarm effect is achieved, and the MCU is replaced to realize the over-temperature alarm function. The electronic component protection circuit has the characteristics of low cost and small size.

Description

An over-temperature alarm circuit Technical Field

[0001] This utility model relates to the field of new energy vehicle technology, specifically to an over-temperature alarm circuit. Background Technology

[0002] Currently, in the field of new energy vehicles, in order to comply with safety regulations and strengthen the protection of electronic devices, more and more electronic devices are adding over-temperature alarm circuits. Existing over-temperature alarm circuits require the addition of an MCU. The MCU detects the temperature of the sensor to achieve over-temperature protection, but adding an MCU is costly and does not conform to the current principle of cost reduction and efficiency improvement. Therefore, an over-temperature alarm circuit is proposed. Summary of the Invention

[0003] The main purpose of this utility model is to provide a solution that can effectively address the problems in the background art.

[0004] To achieve the above objectives, the technical solution adopted by this utility model is as follows: an over-temperature alarm circuit, including a power supply circuit, characterized in that: it further includes a comparator circuit connected to the power supply circuit, a sensor circuit connected to the comparator circuit for detecting the current temperature, and a control circuit connected to the comparator circuit; the control circuit includes the positive terminal of diode D2 connected to the 24V power supply terminal, the positive terminal of capacitor C3 connected to the negative terminal of diode D2, the negative terminal of diode D4, the positive terminal of buzzer SP1, resistors R5 and R6, the negative terminal of capacitor C3 connected to ground, the other end of resistor R6 connected to the other end of resistor R5, the positive terminal of light-emitting diode D3, the positive terminal of diode D4 connected to the negative terminal of light-emitting diode D3, the negative terminal of buzzer SP1, the negative terminal of diode D5, the collector of transistor Q2, the BUZZER_CPU signal connected to resistor R12, resistor R14 connected to resistor R12, the base of transistor Q2, the other end of resistor R14, the emitter of transistor Q2, and the positive terminal of diode D5 connected to ground.

[0005] Preferably, the power supply circuit includes a resistor R1 connected to the 24V power supply terminal, the collector of transistor Q1, a resistor R3 connected to the other end of resistor R1, the cathode of Zener diode D1D, the base of transistor Q1, a resistor R2 connected to the emitter of transistor Q1, a 12V power supply terminal, and the other end of resistor R3, the anode of Zener diode D1, and the other end of resistor R2 connected to ground.

[0006] Preferably, the sensor circuit includes a sensor CON1, a capacitor C6 connected to pin 1 of the sensor CON1, a resistor R15, a SENSOR_DETE signal connected to the other end of the resistor R15, and pin 2 of the sensor CON1 and the other end of the capacitor C6 connected to ground.

[0007] Preferably, the comparison circuit includes capacitor C2, resistors R4, R7, C1, R10, and R11 connected to the 12V power supply terminal, the power supply terminal of integrated circuit U1A, capacitor C5, resistors R8, R13, C4, and R9 connected to the other end of capacitor C2, the positive input terminal of integrated circuit U1A, the other end of resistor R8 connected to the other end of resistor R4, the other end of capacitor C1 connected to ground, the other end of capacitor C4 connected to the other end of resistor R7, the negative input terminal of integrated circuit U1A, the SENSOR_DETE signal, the other end of capacitor C5, the other end of resistor R13, the ground terminal of integrated circuit U1A connected to ground, the other end of resistor R10 connected to the other end of resistor R9, the output terminal of integrated circuit U1A, the positive input terminal of integrated circuit U1B, the output terminal of integrated circuit U1B connected to the negative input terminal of integrated circuit U1B, the other end of resistor R11, and the FMQ_CPU signal.

[0008] This utility model has the following beneficial effects: This circuit is an over-temperature alarm circuit. When the control circuit detects that the output of the comparator circuit is low, the transistor Q2 cannot output. When the output of the comparator circuit is high, it indicates over-temperature. After the transistor Q2 is converted to output low, the buzzer and indicator light will work to achieve the effect of over-temperature alarm. It replaces the MCU to realize the over-temperature alarm function, thereby protecting electronic components. It has the characteristics of low cost and small size. Attached Figure Description

[0009] Figure 1 is a schematic diagram of the over-temperature alarm circuit structure of this utility model;

[0010] Figure 2 is a power supply circuit connection diagram of this utility model;

[0011] Figure 3 is a comparison circuit connection diagram of this utility model;

[0012] Figure 4 is a circuit connection diagram of the sensor of this utility model;

[0013] Figure 5 is a control circuit connection diagram of this utility model.

[0014] Diagram illustrations: 1. Power supply circuit; 2. Comparison circuit; 3. Sensor circuit; 4. Control circuit. Detailed Implementation

[0015] To make the technical means, creative features, objectives and effects of this utility model easier to understand, the present utility model will be further described below in conjunction with specific embodiments.

[0016] As shown in Figures 1-5, an over-temperature alarm circuit includes a power supply circuit 1, characterized in that it further includes a comparator circuit 2 connected to the power supply circuit 1, a sensor circuit 3 connected to the comparator circuit 2 for detecting the current temperature, and a control circuit 4 connected to the comparator circuit 2; the control circuit 4 includes the positive terminal of diode D2 connected to the 24V power supply, the positive terminal of capacitor C3 connected to the negative terminal of diode D2, the negative terminal of diode D4, the positive terminal of buzzer SP1, resistors R5 and R6, the negative terminal of capacitor C3 connected to ground, the other end of resistor R6 connected to the other end of resistor R5, the positive terminal of LED D3, the positive terminal of diode D4 connected to the negative terminal of LED D3, and a buzzer. The negative terminal of SP1, the negative terminal of diode D5, the collector of transistor Q2, the BUZZER_CPU signal connected to resistor R12, resistor R14 connected to resistor 12, the base of transistor Q2, the other end of resistor R14, the emitter of transistor Q2, and the positive terminal of diode D5 are connected to ground. This circuit is an over-temperature alarm circuit. When the control circuit 4 detects that the output of comparator circuit 2 is low, transistor Q2 cannot output. When the output of comparator circuit 2 is high, it indicates an over-temperature. After conversion by transistor Q2, the output is low, which makes the buzzer and indicator light work to achieve the effect of over-temperature alarm. It replaces the MCU to realize the over-temperature alarm function, thereby protecting electronic components. It has the characteristics of low cost and small size.

[0017] In one embodiment, the power supply circuit 1 includes a resistor R1 connected to the 24V power supply terminal, the collector of a transistor Q1, a resistor R3 connected to the other end of the resistor R1, the cathode of a Zener diode D1D, the base of the transistor Q1, a resistor R2 connected to the emitter of the transistor Q1, and the 12V power supply terminal. The other end of the resistor R3, the anode of the Zener diode D1, and the other end of the resistor R2 are connected to ground. After the 24V power is applied, the transistor Q1 turns on after being divided by the resistors R1 and R3, reducing the 24V voltage to 12V to provide voltage to other components.

[0018] In one embodiment, the sensor circuit 3 includes a sensor CON1, a capacitor C6 connected to pin 1 of the sensor CON1, a resistor R15, a SENSOR_DETE signal connected to the other end of the resistor R15, and pin 2 of the sensor CON1 and the other end of the capacitor C6 connected to ground. The sensor CON1 detects the current temperature and feeds back the corresponding resistance value to the negative input terminal of the integrated circuit U1A in the comparator circuit 2 through the SENSOR_DETE signal.

[0019] In one embodiment, the comparator circuit 2 includes a capacitor C2, resistors R4 and R7, a capacitor C1, resistors R10 and R11 connected to the 12V power supply, the power supply terminal of integrated circuit U1A, a capacitor C5, resistors R8 and R13 connected to the other end of capacitor C2, a capacitor C4, resistor R9 connected to the positive input terminal of integrated circuit U1A, the other end of resistor R8 connected to the other end of resistor R4, the other end of capacitor C1 connected to ground, the other end of capacitor C4 connected to the other end of resistor R7, the negative input terminal of integrated circuit U1A, the SENSOR_DETE signal, and the other ends of capacitor C5 and resistor R13. The ground terminal of integrated circuit U1A is connected to ground, the other end of resistor R10 is connected to the other end of resistor R9, the output terminal of integrated circuit U1A, the positive input terminal of integrated circuit U1B, the output terminal of integrated circuit U1B is connected to the negative input terminal of integrated circuit U1B, the other end of resistor R11, and the FMQ_CPU signal; a preset voltage of power supply circuit 1 is connected to the positive input terminal of integrated circuit U1A, and the voltage divider of sensor CON1 is connected to the negative input terminal of integrated circuit U1A. When the negative input terminal of integrated circuit U1A is higher than the positive input terminal of integrated circuit U1A, it indicates normal operation; when the negative input terminal of integrated circuit U1A is lower than the positive input terminal of integrated circuit U1A, it indicates over-temperature.

[0020] In use, after the 24V power-on, the voltage is divided by resistors R1 and R3, turning on transistor Q1 and reducing the voltage to 12V. A preset voltage is connected to the positive input terminal of integrated circuit U1A in comparator circuit 2. The voltage division between sensor CON1 and resistors R15 and R7 is connected to the negative input terminal of integrated circuit U1A. When the temperature of sensor CON1 is higher than 85 degrees Celsius, the voltage entering the negative input terminal of integrated circuit U1A is greater than the voltage entering the positive input terminal, resulting in a low output from integrated circuit U1A. The output of integrated circuit U1B is connected to the negative input terminal of comparator U1B, and the output of integrated circuit U1B also... When the output is low, the low level cannot drive transistor Q2 to turn on. Transistor Q2 is not turned on, and the buzzer and indicator light do not work. When the temperature of sensor CON1 is below 80 degrees, the voltage at the negative input terminal of integrated circuit U1A is less than the voltage at the positive input terminal, and the output terminal of integrated circuit U1A outputs high. This high level signal enters the positive input terminal of integrated circuit U1B. The output terminal of integrated circuit U1B is connected to the negative input terminal of integrated circuit U1B, and integrated circuit U1B outputs high. After the high level signal is divided by resistors R12 and R14, it controls transistor Q2 to turn on and then pull it low. After transistor Q2 is pulled low, buzzer SP1 sounds an alarm, and LED D3 lights up to achieve the purpose of over-temperature alarm.

[0021] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of this utility model. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claims. The scope of protection of this utility model is defined by the appended claims and their equivalents.

Claims

1. An over-temperature alarm circuit, comprising a power supply circuit (1), characterized in that: It also includes a comparator circuit (2) connected to the power supply circuit (1), a sensor circuit (3) connected to the comparator circuit (2) for detecting the current temperature, and a control circuit (4) connected to the comparator circuit (2); the control circuit (4) includes the positive terminal of diode D2 connected to the power supply terminal 24V, the positive terminal of capacitor C3 connected to the negative terminal of diode D2, the negative terminal of diode D4, the positive terminal of buzzer SP1, resistor R5, resistor R6, the negative terminal of capacitor C3 connected to ground, the other end of resistor R6 connected to the other end of resistor R5, the positive terminal of light-emitting diode D3, the positive terminal of diode D4 connected to the negative terminal of light-emitting diode D3, the negative terminal of buzzer SP1, the negative terminal of diode D5, the collector of transistor Q2, the BUZZER_CPU signal connected to resistor R12, the resistor R14 connected to resistor R12, the base of transistor Q2, the other end of resistor R14, the emitter of transistor Q2, and the positive terminal of diode D5 connected to ground.

2. The over-temperature alarm circuit according to claim 1, characterized in that: The power supply circuit (1) includes a resistor R1 connected to the 24V power supply terminal, the collector of transistor Q1, a resistor R3 connected to the other end of resistor R1, the negative terminal of Zener diode D1D, the base of transistor Q1, a resistor R2 connected to the emitter of transistor Q1, a 12V power supply terminal, and the other end of resistor R3, the positive terminal of Zener diode D1, and the other end of resistor R2 connected to ground.

3. The over-temperature alarm circuit according to claim 1, characterized in that: The sensor circuit (3) includes sensor CON1, capacitor C6 connected to pin 1 of sensor CON1, resistor R15, SENSOR_DETE signal connected to the other end of resistor R15, and pin 2 of sensor CON1 and the other end of capacitor C6 connected to ground.

4. The over-temperature alarm circuit according to claim 1, characterized in that: The comparator circuit (2) includes a capacitor C2 connected to the 12V power supply, resistors R4, R7, C1, R10, R11, the power supply terminal of integrated circuit U1A, a capacitor C5 connected to the other end of capacitor C2, resistors R8, R13, C4, R9, the positive input terminal of integrated circuit U1A, the other end of resistor R8 connected to the other end of resistor R4, the other end of capacitor C1 connected to ground, the other end of capacitor C4 connected to the other end of resistor R7, the negative input terminal of integrated circuit U1A, the SENSOR_DETE signal, the other end of capacitor C5, the other end of resistor R13, the ground terminal of integrated circuit U1A connected to ground, the other end of resistor R10 connected to the other end of resistor R9, the output terminal of integrated circuit U1A, the positive input terminal of integrated circuit U1B, the output terminal of integrated circuit U1B connected to the negative input terminal of integrated circuit U1B, the other end of resistor R11, and the FMQ_CPU signal.

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