Over-temperature protection circuit and electronic equipment

Abstract

The utility model provides an over-temperature protection circuit and electronic equipment, and the over-temperature protection circuit comprises a comparison circuit and a switching circuit: the comparison circuit is connected with a temperature sensor, and is used for receiving a first signal value outputted by the temperature sensor, and generating a first comparison signal; the switching circuit is connected with the comparison circuit and used for receiving the first comparison signal and generating a first control signal, and the first control signal is used for controlling a target load; wherein the switching circuit is closed when the first comparison signal is at a low level, and is conducted when the first comparison signal is at a high level. When the first comparison signal is at a high level, the switching circuit is switched on, current is allowed to pass through and power is provided for the target load, and when the first comparison signal is at a low level, the switching circuit is switched off and the current is cut off, so that the target load is protected from overheating damage, a simple circuit is adopted to realize an over-temperature protection function, the overall hardware cost is remarkably reduced, and application is facilitated.

Description

TECHNICAL FIELD

[0001] The utility model relates to circuit technical field, concretely relates to a kind of over-temperature protection circuit and electronic equipment. BACKGROUND

[0002] With the continuous development of circuit technology, the integration of circuit is also higher and higher, leading to the power consumption of circuit work is also higher and higher, the continuous increase of power consumption makes the temperature of circuit rises continuously. High-temperature working environment can affect the reliability of circuit, and even cause the damage of circuit, so it is necessary to set over-temperature protection measure for circuit.

[0003] In the prior art, a special power chip with temperature detection function is generally used to control the conduction or disconnection of circuit, but the special power chip is high in price, and additional software programming and debugging work are needed, so the application is complex. UTILITY MODEL CONTENT

[0004] The utility model is mainly to provide a kind of over-temperature protection circuit and electronic equipment, can realize temperature detection and protection control by pure circuit structure, and it is convenient to apply.

[0005] To solve the above technical problems, the first technical solution provided by the present application is to provide an over-temperature protection circuit, which comprises a comparison circuit and a switching circuit: the comparison circuit is connected with a temperature sensor and is used to receive a first signal value output by the temperature sensor and generate a first comparison signal; the switching circuit is connected with the comparison circuit and is used to receive the first comparison signal and generate a first control signal, which is used to control a target load; wherein the switching circuit is turned off when the first comparison signal is low and is turned on when the first comparison signal is high.

[0006] Preferably, the comparison circuit comprises a first comparator and a second comparator; a positive input terminal of the first comparator is connected to one end of the first resistor, the other end of the first resistor; an output terminal of the first comparator is connected, and the positive input terminal of the first comparator is connected to one end of the third resistor, the first end of the first resistor unit, one end of the first capacitor, one end of the second capacitor, and one end of the fourth resistor, respectively, the other end of the third resistor, the other end of the first resistor unit, and the other end of the first capacitor are connected to the second power supply, respectively, and the other end of the second capacitor and the other end of the fourth resistor are grounded, one end of the fourth resistor is connected to one end of the third capacitor, the other end of the third capacitor is connected to one end of the fifth resistor and the negative input terminal of the first comparator, the other end of the fifth resistor is connected to the output terminal of the temperature sensor and one end of the fourth capacitor, the other end of the fourth capacitor is grounded, the output terminal of the first comparator is connected to the positive input terminal of the second comparator, the positive input terminal of the second comparator is connected to one end of the second resistor, the other end of the second resistor is connected to the second power supply and one end of the sixth resistor, the other end of the sixth resistor is connected to the output terminal of the second comparator, the negative input terminal of the second comparator is connected to the output terminal of the second comparator, and the output terminal of the second comparator is used to output the first comparison signal.

[0007] Preferably, the switch circuit comprises a first switch tube and a second switch tube, a base of the first switch tube is connected to one end of the seventh resistor and one end of the eighth resistor, the other end of the seventh resistor is connected to the output terminal of the second comparator, the other end of the eighth resistor is grounded, an emitter of the first switch tube is grounded, a collector of the first switch tube is connected to one end of the ninth resistor, the other end of the ninth resistor is connected to one end of the tenth resistor and a base of the second switch tube, the other end of the tenth resistor is connected to the second power supply, an emitter of the second switch tube is connected to the second power supply, a collector of the second switch tube is connected to one end of the first fuse and one end of the eleventh resistor, the other end of the first fuse is connected to the positive electrode of the first diode, the negative electrode of the first diode is used to output the first control signal, the other end of the eleventh resistor is grounded, and the negative electrode of the first diode is connected to the negative electrode of the second diode, the positive electrode of the second diode is grounded.

[0008] Preferably, the power supply circuit is further connected to the first power supply, and the power supply circuit is used to convert the first voltage of the first power supply into the second voltage of the second power supply and output the first voltage through the output terminal of the power supply circuit to the comparison circuit and the switch circuit.

[0009] Preferably, the power supply circuit comprises a voltage regulation chip, an input end of the voltage regulation chip is connected with a negative electrode of a third diode, a positive electrode of the third diode is connected with the first power supply, output ends of the voltage regulation chip are connected with power supply input ends of the comparison circuit and the switch circuit respectively, the input end of the voltage regulation chip is connected with a positive electrode of a sixth capacitor and one end of a seventh capacitor, a negative electrode of the sixth capacitor and the other end of the seventh capacitor are grounded, and the output ends of the voltage regulation chip are connected with a positive electrode of an eighth capacitor and one end of a ninth capacitor, a negative electrode of the eighth capacitor and the other end of the ninth capacitor are grounded.

[0010] To solve the above technical problems, the application further provides an electronic device comprising the over-temperature protection circuit.

[0011] The over-temperature protection circuit of the application comprises a comparison circuit and a switch circuit. The comparison circuit compares a first signal value output from a temperature sensor with a preset reference value in the comparison circuit. If the signal value output from the temperature sensor is higher than the preset reference value, the comparison circuit generates a high-level first comparison signal. If the signal value is lower than the reference value, the comparison circuit generates a low-level first comparison signal. The switch circuit receives the first comparison signal from the comparison circuit. When the first comparison signal is high level, the switch circuit is turned on to allow current to pass through and provide power to a target load. When the first comparison signal is low level, the switch circuit is turned off to cut off the current, thereby protecting the target load from overheating damage. The over-temperature protection function is realized by a simple circuit, which significantly reduces the overall hardware cost and facilitates application. BRIEF DESCRIPTION OF DRAWINGS

[0012] The application will be further described below in conjunction with the drawings and embodiments. In the drawings:

[0013] Figure 1 Fig. 1 is a framework schematic diagram of an embodiment of the over-temperature protection circuit provided by the application;

[0014] Figure 2 Fig. 2 is a power supply circuit schematic diagram of an embodiment of the over-temperature protection circuit provided by the application;

[0015] Figure 3 Fig. 3 is a comparison circuit circuit diagram of an embodiment of the over-temperature protection circuit provided by the application;

[0016] Figure 4 Fig. 4 is a switch circuit circuit diagram of an embodiment of the over-temperature protection circuit provided by the application;

[0017] Figure 5 Fig. 5 is a framework schematic diagram of an embodiment of the electronic device provided by the application. DETAILED DESCRIPTION

[0018] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. It can be understood that the specific embodiments described herein are only used to explain the present application, rather than limit the present application. In addition, it should be noted that, for the convenience of description, only parts related to the present application are shown in the drawings, rather than all structures. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application. The basic principles and main features of the present application and the advantages of the present application are shown and described above. It should be understood by those skilled in the art that the present application is not limited by the above embodiments, and the above embodiments and descriptions in the specification are only to illustrate the principles of the present application. Without departing from the spirit and scope of the present application, various changes and improvements can be made to the present application, and these changes and improvements all fall within the scope of the present application. The scope of protection of the present application is defined by the appended claims and their equivalents.

[0019] The terms "first", "second", "third" in the present application are only used for description purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features limited by "first", "second", "third" can explicitly or implicitly include at least one of the features. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device including a series of steps or units is not limited to the listed steps or units, but can optionally include steps or units not listed, or can optionally include other steps or units inherent to the process, method, product or device.

[0020] The over-temperature protection circuit of the present application is suitable for temperature protection of electronic devices of new energy vehicles in the field of new energy vehicles. The over-temperature protection of the prior art often needs to increase an MCU, and the MCU realizes over-temperature protection by detecting the temperature of a sensor. However, the cost of the MCU is relatively high, and programming and debugging are required, which is difficult to apply to scenes with programming and debugging difficulties and cost limitations.

[0021] To solve the above problems, the present application provides an over-temperature protection circuit. Please refer to Figure 1 , Figure 1 is a frame schematic diagram of an embodiment of the over-temperature protection circuit provided by the present application.

[0022] The over-temperature protection circuit 10 provided by the application comprises: a comparison circuit 12 connected with a temperature sensor, configured to receive a first signal value output by the temperature sensor and generate a first comparison signal; and a switch circuit 13 connected with the comparison circuit 12, configured to receive the first comparison signal and generate a first control signal for controlling a target load, wherein the switch circuit 13 is closed when the first comparison signal is at a low level and is turned on when the first comparison signal is at a high level.

[0023] In the above scheme, by setting the comparison circuit 12 and the switch circuit 13, the comparison circuit 12 receives the first signal value output by the temperature sensor and compares the first signal value with a preset reference value in the comparison circuit 12. If the signal value output by the temperature sensor is higher than the preset reference value, the comparison circuit 12 generates a high-level first comparison signal, and if the signal value is lower than the reference value, the comparison circuit 12 generates a low-level first comparison signal. The switch circuit 13 receives the first comparison signal from the comparison circuit 12. When the first comparison signal is at a high level, the switch circuit 13 is turned on to allow current to pass through and provide power to the target load. When the first comparison signal is at a low level, the switch circuit 13 is closed to cut off the current, thereby protecting the target load from overheating damage. The over-temperature protection function is realized by using a simple circuit, which significantly reduces the overall hardware cost and facilitates application.

[0024] In some embodiments, the first power supply of the working environment is not suitable for the working voltage requirement of the over-temperature protection circuit 10 and subsequent modules, so it is necessary to add a power supply circuit 11 between the over-temperature protection circuit 10 and the first voltage, which is used to convert the first power supply into a power supply voltage suitable for the over-temperature protection circuit 10 and subsequent circuits.

[0025] The over-temperature protection circuit further comprises a power supply circuit 11 connected with the first power supply, which is configured to convert the first voltage of the first power supply into a second voltage output by a second power supply and output the first voltage to the comparison circuit 12 and the switch circuit 13 through an output end of the power supply circuit 11.

[0026] In some specific embodiments, as shown in Figure 2 Figure 2 ​is a power supply circuit schematic diagram of an embodiment of the over-temperature protection circuit provided in the present application. The power supply circuit comprises a voltage regulating chip U1. The input end of the voltage regulating chip U1 is connected with the negative electrode of a third diode D1. The positive electrode of the third diode D1 is connected with a first power supply. The output end of the voltage regulating chip U1 is connected with the power supply input end of a comparison circuit 12 and a switch circuit 13 respectively. The input end of the voltage regulating chip U1 is connected with the positive electrode of a sixth capacitor C1 and one end of a seventh capacitor C3. The negative electrode of the sixth capacitor C1 and the other end of the seventh capacitor C3 are grounded. The output end of the voltage regulating chip U1 is connected with the positive electrode of an eighth capacitor C2 and one end of a ninth capacitor C4. The negative electrode of the eighth capacitor C2 and the other end of the ninth capacitor C4 are grounded.

[0027] In some application scenarios, the voltage regulating chip U1 can be a step-down chip. The voltage regulating chip U1 is used to reduce and stabilize the voltage of the first power supply to a second voltage output, so as to meet the requirement of the comparison circuit 12 and the switch circuit 13 for a lower and stable power supply voltage. In other application scenarios, the voltage regulating chip U1 can be a step-up chip, which is used to increase and stabilize the voltage of the first power supply to a second voltage output, so as to adapt to circuit elements or specific working conditions that require a higher power supply voltage.

[0028] In some embodiments, please refer to Figure 3 , Figure 3is a comparison circuit diagram of an embodiment of the over-temperature protection circuit provided by the present application, and the comparison circuit includes a first comparator U2A and a second comparator U2B; one end of a first resistor R7 is connected to the positive input end of the first comparator U2A, and the other end of the first resistor R7 is connected to the output end of the first comparator U2A; the positive input end of the first comparator U2A is respectively connected to one end of a third resistor R3, one end of a first resistor unit, one end of a first capacitor C6, one end of a second capacitor C8, and one end of a fourth resistor R12; the other end of the third resistor R3, the other end of the first resistor unit, and the other end of the first capacitor C6 are respectively connected to a second power supply; the other end of the second capacitor C8 and the other end of the fourth resistor R12 are grounded; one end of the fourth resistor R12 is connected to one end of a third capacitor C7; the other end of the third capacitor C7 is connected to one end of a fifth resistor R13 and the negative input end of the first comparator U2A; the other end of the fifth resistor R13 is connected to the output end of a temperature sensor and one end of a fourth capacitor C9; the other end of the fourth capacitor C9 is grounded; the output end of the first comparator U2A is connected to the positive input end of the second comparator U2B; the positive input end of the second comparator U2B is connected to one end of a second resistor R8; the other end of the second resistor R8 is connected to the second power supply and one end of a sixth resistor R9; the other end of the sixth resistor R9 is connected to the output end of the second comparator U2; the negative input end of the second comparator U2 is connected to the output end of the second comparator U2; and the output end of the second comparator U2 is used to output a first comparison signal.

[0029] In some specific embodiments, the power supply end of the first comparator U2B is connected to the second power supply and one end of a capacitor C5, and the other end of the capacitor C5 is grounded. The first resistor unit can be composed of one resistor or a plurality of series-connected resistor strings, for example, as shown in Figure 3 the first resistor unit includes the resistor R6 and the resistor R7 connected in series, one end of the resistor R6 is connected as one end of the first resistor unit, the other end of the resistor R6 is connected to the resistor R7, and the other end of the resistor R7 is the other end of the first resistor unit, wherein the resistor R2, the resistor R5, the resistor R6, the resistor R12, the resistor R13, the capacitor C7, and the capacitor C9 together with the temperature sensor constitute a voltage division circuit, which is used to adjust the voltage range of the temperature sensor output signal to match the input range of the first comparator. In specific use scenarios, the reference voltage of the positive input end of the first comparator U2A can be changed by adjusting the values of the resistors and capacitors and selecting a sensor with specific temperature characteristics. For example, if it is necessary to set the protection temperature at about 4°C, it is necessary to adjust the values of the resistors and capacitors to ensure that when the temperature of the sensor is higher than 4°C, the voltage of the negative input end of the first comparator U2A is lower than that of the positive input end, so that the voltage of the negative input end of the first comparator U2A is lower than that of the positive input end, thereby triggering the second comparator C to output a high-level signal.

[0030] In some embodiments, see Figure 4 , Figure 4 This is a circuit diagram of a switching circuit according to an embodiment of the over-temperature protection circuit provided in this application. The switching circuit includes a first switching transistor Q2 and a second switching transistor Q1. The base of the first switching transistor Q2 is connected to one end of a seventh resistor R10 and one end of an eighth resistor R11. The other end of the seventh resistor R10 is connected to the output terminal of a second comparator U2B. The other end of the eighth resistor R11 is grounded. The emitter of the first switching transistor Q2 is grounded. The collector of the first switching transistor Q2 is connected to one end of a ninth resistor R3. The other end of the ninth resistor R3 is connected to one end of a tenth resistor R1. The base of the first diode is connected to the first diode, and the other end of the tenth resistor R1 is connected to the second power supply. The emitter of the second diode Q1 is connected to the second power supply. The collector of the second diode Q1 is connected to one end of the first fuse F1 and one end of the eleventh resistor R4. The other end of the first fuse F1 is connected to the anode of the first diode D2. The cathode of the first diode D2 is used to output the first control signal. The other end of the eleventh resistor R4 is grounded. The cathode of the first diode D2 is connected to the cathode of the second diode D1. The anode of the second diode D1 is grounded.

[0031] In practical use, the first power supply can be 24V, and the second power supply can be 12V. After the first power supply of 24V is powered on, it enters the voltage regulation chip U1 through the third diode D1. The voltage regulation chip U1 reduces the 24V voltage to 12V. By adjusting the resistors, capacitors, and selected temperature sensor parameters in the circuit, the circuit is set so that when the sensor temperature is higher than 4℃, the voltage entering the negative input terminal of the first comparator U2A is lower than the voltage entering the positive input terminal of the first comparator U2A. The high-level signal output from the output terminal of the first comparator U2A is input to the positive input terminal of the second comparator U2B. The negative input terminal of the second comparator U2B is connected to the second comparator U2B. At the positive input terminal of U2B, the second comparator U2B also outputs a high level. This high-level signal is divided by resistors R10 and R11, which controls the first switch Q2 to turn on and pull it low, and the second switch Q1 to turn on and pull it high, thus controlling the target load to work. When the temperature sensor temperature is below 1℃, the voltage entering the negative input terminal of the first comparator U2A is not lower than the voltage entering the positive input terminal of the first comparator U2A. The second comparator U2B outputs a low level. After being divided by resistors R10 and R11, the low level is pulled low through resistor R4. Neither the first switch Q2 nor the second switch Q1 is turned on, and the switching circuit 13 does not control the target load to work, thus achieving the purpose of over-temperature protection.

[0032] In the above solution, the over-temperature protection circuit 10 provided in this application includes a comparator circuit 12 and a switch circuit 13. The comparator circuit 12 receives a first signal value output from the temperature sensor and compares it with a preset reference value inside the comparator circuit 12. If the signal value output by the temperature sensor is higher than the preset reference value, the comparator circuit 12 will generate a high-level first comparison signal. If it is lower than the reference value, the comparator circuit 12 will generate a low-level first comparison signal. The switch circuit 13 receives the first comparison signal from the comparator circuit 12. When the first comparison signal is high, the switch circuit 13 is turned on, allowing current to flow and providing power to the target load. When the first comparison signal is low, the switch circuit 13 is turned off, cutting off the current, thereby protecting the target load from overheating damage. The over-temperature protection function is achieved with a simple circuit, significantly reducing the overall hardware cost and facilitating application.

[0033] This application also provides an electronic device, please refer to [link to application]. Figure 5 , Figure 5 This is a schematic diagram of a framework of an embodiment of the electronic device provided in this application. The electronic device 50 of this embodiment includes the over-temperature protection circuit 10 of the above embodiment. Optionally, the electronic device 50 includes devices such as a drive unit or energy storage unit in a new energy vehicle that contain the over-temperature protection circuit 10.

[0034] The electronic device 50 provided in this application includes the over-temperature protection circuit 10 in the above embodiments, which includes a comparison circuit 12 and a switching circuit 13. The comparison circuit 12 receives a first signal value output from a temperature sensor and compares it with a preset reference value inside the comparison circuit 12. If the signal value output by the temperature sensor is higher than the preset reference value, the comparison circuit 12 generates a high-level first comparison signal. If it is lower than the reference value, the comparison circuit 12 generates a low-level first comparison signal. The switching circuit 13 receives the first comparison signal from the comparison circuit 12. When the first comparison signal is high, the switching circuit 13 is turned on, allowing current to flow and providing power to the target load. When the first comparison signal is low, the switching circuit 13 is turned off, cutting off the current, thereby protecting the target load from overheating damage. The over-temperature protection function is achieved using a simple circuit, significantly reducing the overall hardware cost and facilitating application.

[0035] It is understood that those skilled in the art can make equivalent substitutions or modifications based on the technical solution and inventive concept of this utility model, and all such substitutions or modifications should fall within the protection scope of the appended claims of this utility model.

Claims

1. An over-temperature protection circuit, characterized in that, include: Comparison circuit: connected to the temperature sensor, used to receive the first signal value output by the temperature sensor and generate the first comparison signal; Switching circuit: connected to the comparison circuit, used to receive the first comparison signal and generate a first control signal, the first control signal being used to control the target load; The switching circuit is turned off when the first comparison signal is low and turned on when the first comparison signal is high. The comparison circuit includes a first comparator and a second comparator. The output terminal of the first comparator is connected to the positive input terminal of the second comparator, and the negative input terminal of the second comparator is connected to the output terminal of the second comparator. The output terminal of the second comparator is used to output the first comparison signal.

2. The over-temperature protection circuit according to claim 1, characterized in that, The positive input terminal of the first comparator is connected to one end of the first resistor, and the other end of the first resistor is connected to the output terminal of the first comparator. The positive input terminal of the first comparator is connected to one end of the third resistor, one end of the first resistor unit, one end of the first capacitor, one end of the second capacitor, and one end of the fourth resistor. The other ends of the third resistor, the first resistor unit, and the first capacitor are respectively connected to the second power supply. The other ends of the second capacitor and the fourth resistor are grounded. One end of the fourth resistor is connected to one end of the third capacitor. The other end of the third capacitor is connected to one end of the fifth resistor and the negative input terminal of the first comparator. The other end of the fifth resistor is connected to the output terminal of the temperature sensor and one end of the fourth capacitor. The other end of the fourth capacitor is grounded. The positive input terminal of the second comparator is connected to one end of the second resistor. The other end of the second resistor is connected to the second power supply and one end of the sixth resistor. The other end of the sixth resistor is connected to the output terminal of the second comparator.

3. The over-temperature protection circuit according to claim 2, characterized in that, The switching circuit includes a first switching transistor and a second switching transistor. The base of the first switching transistor is connected to one end of a seventh resistor and one end of an eighth resistor. The other end of the seventh resistor is connected to the output terminal of the second comparator. The other end of the eighth resistor is grounded. The emitter of the first switching transistor is grounded. The collector of the first switching transistor is connected to one end of a ninth resistor. The other end of the ninth resistor is connected to one end of a tenth resistor and the base of the second switching transistor. The other end of the tenth resistor is connected to the second power supply. The emitter of the second switching transistor is connected to the second power supply. The collector of the second switching transistor is connected to one end of a first fuse and one end of an eleventh resistor. The other end of the fuse is connected to the anode of a first diode. The cathode of the first diode is used to output the first control signal. The other end of the eleventh resistor is grounded. The cathode of the first diode is connected to the cathode of a second diode. The anode of the second diode is grounded.

4. The over-temperature protection circuit according to claim 2 or 3, characterized in that, It also includes a power supply circuit, which is connected to a first power supply. The power supply circuit is used to convert a first voltage of the first power supply into a second voltage output of the second power supply, and to supply the first voltage output to the comparison circuit and the switching circuit through the output terminal of the power supply circuit.

5. The over-temperature protection circuit according to claim 4, characterized in that, The power supply circuit includes a voltage regulator chip. The input terminal of the voltage regulator chip is connected to the negative terminal of the third diode, and the positive terminal of the third diode is connected to the first power supply. The output terminal of the voltage regulator chip is connected to the power input terminals of the comparator circuit and the switching circuit, respectively. The input terminal of the voltage regulator chip is connected to the positive terminal of the sixth capacitor and one end of the seventh capacitor. The negative terminal of the sixth capacitor and the other end of the seventh capacitor are grounded. The output terminal of the voltage regulator chip is connected to the positive terminal of the eighth capacitor and one end of the ninth capacitor. The negative terminal of the eighth capacitor and the other end of the ninth capacitor are grounded.

6. An electronic device, characterized in that, Includes the over-temperature protection circuit described in any one of claims 1-5.

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