Over-temperature, over-voltage and over-current protection circuit and circuit board

Abstract

The embodiment of the utility model discloses an over-temperature, over-voltage and over-current protection circuit and a circuit board, and relates to the field of protection circuits, the over-temperature, over-voltage and over-current protection circuit comprises a control module, a temperature detection module, a current detection module, a voltage detection module and a protection trigger module comprising a first trigger unit and a second trigger unit, wherein the temperature detection module and the current detection module are electrically connected with the first trigger unit, the first trigger unit and the voltage detection module are electrically connected with the second trigger unit, and the second trigger unit is electrically connected with the control module. By adopting the embodiment of the invention, a good protection effect can be provided when lightning stroke surge occurs in the circuit, the circuit can be protected when over-temperature, over-voltage and over-current abnormal conditions occur in the circuit, the reliability and the stability of circuit work are improved, over-temperature, over-current and over-voltage protection is realized only by using one pin of the control unit, and the circuit integration is high.

Description

Technical Field

[0001] The present application relates to the field of protection circuits, and in particular to an over-temperature, over-voltage and over-current protection circuit and a circuit board. Background Art

[0002] With the continuous development of electronic technology, the circuit solution technology used in various electronic products is also constantly improving and perfecting. In order to ensure the stability of circuit operation, it is necessary to detect the temperature, voltage and current of the circuit during operation to ensure that the temperature, voltage and current values ​​of the circuit are maintained within the preset range during operation.

[0003] At present, multiple detection chips or multiple detection modules are generally used to detect the temperature, voltage and current of the circuit during operation, so as to timely detect abnormalities such as overcurrent, overvoltage and overtemperature in the circuit. However, the above protection circuit has the problem of low integration, which means that it requires more space to accommodate all components and circuits, thereby increasing the volume and weight of the entire circuit. This situation may limit the application of the protection circuit in some devices that need to be light and portable. In addition, low integration will also lead to an increase in manufacturing costs, reducing the practicality and economy of the protection circuit. Utility Model Content

[0004] The embodiment of the present application provides an over-temperature, over-voltage and over-current protection circuit, which can protect the circuit when abnormal conditions of over-temperature, over-voltage and over-current occur in the circuit, improve the reliability and stability of the circuit operation, and only use one pin of the control unit to achieve over-temperature, over-current and over-voltage protection, and the circuit has high integration. The technical solution is as follows:

[0005] In a first aspect, an embodiment of the present application provides an over-temperature, over-voltage and over-current protection circuit, and the over-temperature, over-voltage and over-current protection circuit includes:

[0006] A control module, a temperature detection module, a current detection module, a voltage detection module, and a protection trigger module including a first trigger unit and a second trigger unit;

[0007] Wherein, the temperature detection module and the current detection module are electrically connected to the first trigger unit respectively, the first trigger unit and the voltage detection module are electrically connected to the second trigger unit respectively, and the second trigger unit is electrically connected to the control module;

[0008] A temperature detection module, used to detect a target temperature of the over-temperature, over-voltage and over-current protection circuit, and to send a first protection signal to the first trigger unit when the temperature value of the target temperature exceeds a preset temperature value;

[0009] A current detection module, used to detect a target current of the over-temperature, over-voltage and over-current protection circuit, and to send a second protection signal to the first trigger unit when the current value of the target current exceeds a preset current value;

[0010] A voltage detection module, used to detect a target voltage of the over-temperature, over-voltage and over-current protection circuit, and to send a third protection signal to the second trigger unit when a voltage value of the target voltage exceeds a preset voltage value;

[0011] A first trigger unit, configured to send a first trigger signal to a second trigger unit upon receiving a first protection signal or a second protection signal;

[0012] A second trigger unit, configured to send a second trigger signal to the control module upon receiving the first trigger signal or the third protection signal;

[0013] The control module is used to switch to the protection mode when receiving the second trigger signal.

[0014] In a second aspect, an embodiment of the present application provides a circuit board, which includes the over-temperature, over-voltage and over-current protection circuit provided in the first aspect.

[0015] The beneficial effects brought about by the technical solutions provided by some embodiments of the present application include at least:

[0016] The over-temperature, over-voltage and over-current protection circuit provided by the present application includes: a control module, a temperature detection module, a current detection module, a voltage detection module, and a protection trigger module including a first trigger unit and a second trigger unit. The protection trigger module is used to switch to a protection mode to protect the circuit when the temperature value of the target temperature detected by the temperature detection module exceeds a preset temperature value, or the current value of the target current detected by the current detection module exceeds a preset current value, or the voltage value of the target voltage detected by the voltage detection module exceeds a preset voltage value. The protection circuit provided by the present application has a high degree of integration, and only one port of the control module is required to realize over-temperature, over-voltage and over-current protection, which reduces the volume and weight of the entire circuit, and is suitable for use in some devices that need to be light and portable, reducing the increase in manufacturing costs and improving the practicality and economy of the protection circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0018] Figure 1 It is a structural schematic diagram of an over-temperature, over-voltage and over-current protection circuit provided in an embodiment of the present application;

[0019] Figure 2 It is a structural schematic diagram of an over-temperature, over-voltage and over-current protection circuit provided in an embodiment of the present application;

[0020] Figure 3 It is a structural schematic diagram of an over-temperature, over-voltage and over-current protection circuit provided in an embodiment of the present application;

[0021] Figure 4 It is a structural schematic diagram of an over-temperature, over-voltage and over-current protection circuit provided in an embodiment of the present application;

[0022] Figure 5 It is a structural schematic diagram of an over-temperature, over-voltage and over-current protection circuit provided in an embodiment of the present application;

[0023] Figure 6 It is a structural schematic diagram of an over-temperature, over-voltage and over-current protection circuit provided in an embodiment of the present application. DETAILED DESCRIPTION

[0024] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0025] In the description of the present application, it should be understood that the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. In the description of the present application, it should be noted that, unless otherwise clearly specified and limited, "including" and "having" and any of their variations are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but optionally also includes steps or units that are not listed, or optionally also includes other steps or units inherent to these processes, methods, products or devices. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood in specific circumstances. In addition, in the description of the present application, unless otherwise specified, "multiple" refers to two or more. "And / or" describes the association relationship of associated objects, indicating that there can be three relationships, for example, A and / or B, which can represent: A exists alone, A and B exist at the same time, and B exists alone. The character " / " generally indicates that the associated objects before and after are an "or" relationship.

[0026] The present application is described in detail below with reference to specific embodiments.

[0027] With the continuous development of electronic technology, the circuit solution technology used in various electronic products is also constantly improving and perfecting. In order to ensure the stability of circuit operation, it is necessary to detect the temperature, voltage and current of the circuit during operation to ensure that the temperature, voltage and current values ​​of the circuit are maintained within the preset range during operation.

[0028] At present, multiple detection chips or multiple detection modules are generally used to detect the temperature, voltage and current of the circuit during operation, so as to timely detect abnormalities such as overcurrent, overvoltage and overtemperature in the circuit. However, the above protection circuit has the problem of low integration, which means that it requires more space to accommodate all components and circuits, thereby increasing the volume and weight of the entire circuit. This situation may limit the application of the protection circuit in some devices that need to be light and portable. In addition, low integration will also lead to an increase in manufacturing costs, reducing the practicality and economy of the protection circuit.

[0029] like Figure 1 As shown, it is a schematic diagram of an over-temperature, over-voltage and over-current protection circuit proposed in an embodiment of the present application, and the over-temperature, over-voltage and over-current protection circuit includes: a control module 101, a temperature detection module 102, a current detection module 103, a voltage detection module 104, and a protection trigger module 105 including a first trigger unit 1051 and a second trigger unit 1052. The temperature detection module 102 and the current detection module 103 are electrically connected to the first trigger unit 1051, respectively, the first trigger unit 1051 and the voltage detection module 104 are electrically connected to the second trigger unit 1052, and the second trigger unit 1052 is electrically connected to the control module 101.

[0030] The temperature detection module 102 is used to detect the target temperature of the over-temperature, over-voltage and over-current protection circuit, and send a first protection signal to the first trigger unit 1051 when the temperature value of the target temperature exceeds the preset temperature value. The target temperature can be understood as indicating the temperature of a certain component or a certain range detected by the temperature detection module 102. The first protection signal can be any signal, for example, the first protection signal is a high-level signal. The preset temperature value is a temperature value set by relevant personnel as needed. In other words, when the temperature value of the target temperature is detected to exceed the preset temperature value, the over-temperature, over-current and over-voltage protection circuit has an abnormal over-temperature condition.

[0031] The current detection module 103 is used to detect the target current of the over-temperature, over-voltage and over-current protection circuit, and to send a second protection signal to the first trigger unit 1051 when the current value of the target current exceeds the preset current value. The target current can be understood as indicating the current of a certain component or a certain circuit node detected by the current detection module 103. The second protection signal can be any signal, for example, the second protection signal is a high-level signal. The preset current value is a current value set by relevant personnel as needed. In other words, when it is detected that the current value of the target current exceeds the preset current value, an abnormal overcurrent occurs in the over-temperature, over-current and over-voltage protection circuit.

[0032] The voltage detection module 104 is used to detect the target voltage of the over-temperature, over-voltage and over-current protection circuit, and to send a third protection signal to the second trigger unit when the voltage value of the target voltage exceeds the preset voltage value. The target voltage can be understood as indicating the current of a certain component or a certain circuit node detected by the voltage detection module 104. The third protection signal can be any signal, for example, the third protection signal is a low-level signal. The preset voltage value is a current value set by relevant personnel as needed. In other words, when it is detected that the current value of the target current exceeds the preset voltage value, an abnormal overvoltage occurs in the over-temperature, over-current and over-voltage protection circuit.

[0033] The first trigger unit 1051 is used to send the first trigger signal to the second trigger unit when receiving the first protection signal or the second protection signal. For example, when receiving the first protection signal or the second protection signal, the first trigger unit 1051 switches from the off state to the on state, so that the second trigger unit 1052 receives a low-level signal as the first trigger signal based on the first trigger unit 1051 in the on state.

[0034] The second trigger unit 1052 is used to send a second trigger signal to the control module 101 when receiving the first trigger signal or the third protection signal. The second trigger signal can be a level signal, or a light signal, a sound signal, or any other type of signal. For example, the second trigger unit 1052 includes an optocoupler diode. When receiving the first trigger signal or the third protection signal, the optocoupler diode included in the second trigger unit 1052 emits light, thereby sending an optical signal to the control module 101 as the second trigger signal.

[0035] The control module 101 is used to switch to a protection mode when receiving a second trigger signal, so as to protect the target circuit including over-temperature, over-voltage and over-current protection current. The control module 101 may include a control chip, and the second trigger signal is received through the pin of the control chip. The control module 101 switches the protection mode, which may be to stop the operation of the target circuit, control the target circuit to enter a standby state, turn off the power input of the target circuit, cool down the target circuit, reduce the voltage and current, and other corresponding operations, etc., and the embodiments of the present application do not impose any restrictions on this.

[0036] The over-temperature, over-voltage and over-current protection circuit provided by the present application includes: a control module, a temperature detection module, a current detection module, a voltage detection module, and a protection trigger module including a first trigger unit and a second trigger unit. The protection trigger module is used to switch to a protection mode to protect the circuit when the temperature value of the target temperature detected by the temperature detection module exceeds a preset temperature value, or the current value of the target current detected by the current detection module exceeds a preset current value, or the voltage value of the target voltage detected by the voltage detection module exceeds a preset voltage value. The protection circuit provided by the present application has a high degree of integration, and only one port of the control module is required to realize over-temperature, over-voltage and over-current protection, which reduces the volume and weight of the entire circuit, and is suitable for use in some devices that need to be light and portable, reducing the increase in manufacturing costs and improving the practicality and economy of the protection circuit.

[0037] like Figure 2 As shown, it is a schematic diagram of an over-temperature, over-voltage and over-current protection circuit provided by an embodiment of the present application, and the over-temperature, over-voltage and over-current protection circuit includes: a control module 201, a temperature detection module 202, a current detection module 203, a voltage detection module 204, a protection trigger module 205 including a first trigger unit 2051 and a second trigger unit 2052, and a reference module 206. The connection method of the control module 201, the temperature detection module 202, the current detection module 203, the voltage detection module 204 and the protection trigger module 205 is as follows Figure 1 As shown, which will not be described in detail here, the reference module 206 is electrically connected to the temperature detection module 202 and the current detection module 203 respectively.

[0038] The reference module 206 is used to provide a reference voltage to the temperature detection module 202 and the current detection module 203. Specifically, based on the reference voltage provided by the reference module 206, the temperature detection module 202 detects whether the temperature value of the target temperature exceeds the preset temperature value, and enables the current detection module 203 to detect whether the current value of the target current exceeds the preset current value.

[0039] In other words, according to the voltage value of the reference voltage provided by the reference module 206 and the preset temperature value, and the mapping relationship between the preset temperature value, the preset temperature value and the preset current value are set by adjusting the voltage value of the reference module 206. Based on the circuit structure provided in this embodiment, the preset temperature value and the preset current value can be flexibly set to meet the protection range requirements corresponding to the over-temperature protection and the protection range requirements corresponding to the over-current protection.

[0040] Specifically, if Figure 2 As shown, the temperature detection module 202 includes: a temperature detection unit and a first comparison unit. The first comparison unit 2022 is connected to the temperature detection unit 2021, the reference module 206 and the first trigger unit 2051 respectively.

[0041] The first comparison unit 2022 is used to detect the target temperature of the over-temperature, over-voltage and over-current protection circuit through the temperature detection unit 2021, and when the temperature value of the target temperature exceeds the preset temperature value, send a first protection signal to the first trigger unit 2051. For example, when the target temperature exceeds the preset temperature value, the first comparison unit 2022 switches from the off state to the on state, so that the first trigger unit 2051 receives a high level signal as the first protection signal.

[0042] The current detection module 203 includes: a second comparison unit 2032 and a current detection unit 2032. The second comparison unit 2032 is connected to the current detection unit 2031, the reference module 206 and the first trigger unit 2051 respectively.

[0043] The second comparison unit 2032 is used to detect the target current of the over-temperature, over-voltage and over-current protection circuit through the current detection unit 2031, and when the current value of the target current exceeds the preset current value, send a second protection signal to the first trigger unit 2051. For example, when the target current exceeds the preset current value, the second comparison unit 2032 switches from the off state to the on state, so that the first trigger unit 2051 receives a high level signal as the second protection signal.

[0044] In this embodiment, when the temperature value of the target temperature exceeds the preset temperature value, or the temperature value of the target current exceeds the preset current value, the first comparison unit and the second comparison unit respond quickly to send the first protection signal or the second protection signal to the first trigger unit to protect the circuit in time to prevent abnormal damage to the circuit due to overtemperature or overcurrent.

[0045] based on Figure 2 The embodiment shown, as Figure 3 , which is a schematic diagram of the structure of an over-temperature, over-voltage and over-current protection circuit provided by an embodiment of the present application. The connection structure of the control module 201, the temperature detection module 202, the current detection module 203, the voltage detection module 204, the protection trigger module 205 including the first trigger unit 2051 and the second trigger unit 2052, and the reference module 206 is shown in FIG. Figure 2 As shown, no further description is given here.

[0046] In this embodiment, the temperature detection unit 2021 includes: a thermistor NTC, and the first comparison unit 2022 includes: a first resistor R1, a second resistor R2, a third resistor R4, a fourth resistor F4, a first operational amplifier comparator U1A and a first diode D1.

[0047] Among them, the first end of the thermistor NTC is connected to the detection end V, the second end of the thermistor NTC is connected to the first end of the first resistor R1, the second end of the first resistor R1 is respectively connected to the first end of the second resistor R2 and the non-inverting input end of the first operational amplifier comparator U1A, the second end of the second resistor R2 is grounded, the first end of the third resistor R3 is respectively connected to the inverting input end of the first operational amplifier comparator U1A and the first end of the fourth resistor R4, the second end of the third resistor R3 is connected to the reference module 206, the second end of the fourth resistor R4 is grounded, the output end of the first operational amplifier comparator U1A is connected to the positive electrode of the first diode D1, and the negative electrode of the first diode D1 is connected to the first trigger unit 2051.

[0048] The resistance of the thermistor NTC decreases as the temperature decreases. When the target temperature exceeds the preset temperature value, the resistance of the thermistor NTC decreases to below the target resistance value. Based on the low resistance value of the thermistor NTC, the voltage value applied by the temperature detection terminal V to the first resistor R1 and the second resistor R2 increases. The first resistor R1 and the second resistor R2 divide the voltage value of the temperature detection terminal V based on their respective corresponding resistance values. Since the non-inverting input terminal of the first operational amplifier comparator U1A is connected to the second end of the first resistor R1 and the first end of the second resistor R2, the voltage value input to the non-inverting input terminal of the first operational amplifier comparator U1A increases, that is, the non-inverting input terminal of the first operational amplifier comparator U1A inputs a high voltage. Further, the first operational amplifier comparator U1A outputs a high level signal to the first trigger unit 2051 based on the reference voltage as the first protection signal.

[0049] The current detection unit 2031 includes: a fifth resistor R5 , and the second comparison unit includes: a sixth resistor R6 , a seventh resistor R7 , a first capacitor C1 , a second operational amplifier comparator U1B and a second diode D2 .

[0050] The first end of the sixth resistor R6 is grounded, the second end of the sixth resistor R6 is respectively connected to the first end of the seventh resistor R7, the inverting input end of the second operational amplifier comparator U1B, and the first end of the first capacitor C1, the second end of the seventh resistor R7 is connected to the reference module 206, the first end of the fifth resistor R5 is connected to the current detection end V, the second end of the fifth resistor R5 is connected to the non-inverting input end of the second operational amplifier comparator U1B, the output end of the second operational amplifier comparator U1B is respectively connected to the second end of the first capacitor C1 and the positive electrode of the second diode D2, and the negative electrode of the second diode D2 is connected to the first trigger unit 2051.

[0051] The voltage value of the voltage of the fifth resistor R5 increases with the increase of the target current. When the current value of the target current exceeds the preset current value, the voltage value of the voltage of the fifth resistor R5 increases to above the target voltage value. Based on the high voltage input to the non-inverting input terminal of the second operational amplifier comparator U1B, the second operational amplifier comparator U1B further outputs a high-level signal to the first trigger unit 2051 as a second protection signal based on the reference voltage.

[0052] The over-temperature, over-voltage and over-current protection circuit provided by the present application includes: a control module, a temperature detection module, a current detection module, a voltage detection module, and a protection trigger module including a first trigger unit and a second trigger unit. The protection trigger module is used to switch to a protection mode to protect the circuit when the temperature value of the target temperature detected by the temperature detection module exceeds a preset temperature value, or the current value of the target current detected by the current detection module exceeds a preset current value, or the voltage value of the target voltage detected by the voltage detection module exceeds a preset voltage value. The protection circuit provided by the present application has a high degree of integration, and only one port of the control module is required to realize over-temperature, over-voltage and over-current protection, which reduces the volume and weight of the entire circuit, and is suitable for use in some devices that need to be light and portable, reducing the increase in manufacturing costs and improving the practicality and economy of the protection circuit.

[0053] like Figure 4 As shown, it is a structural schematic diagram of an over-current, over-temperature, over-voltage and over-current protection circuit provided by an embodiment of the present application, including: a control module 301, a temperature detection module 302, a current detection module 303, a voltage detection module 304, and a protection trigger module 305 including a first trigger unit 3051 and a second trigger unit 3052. The connection structure of the control module 301, the temperature detection module 302, the current detection module 303, the voltage detection module 304 and the protection trigger module 305 is as shown in FIG. Figure 1 As shown, no further description is given here.

[0054] In this embodiment, the voltage detection module 304 includes: a voltage detection unit 3041 and a third comparison unit 3042. The third comparison unit 3042 is connected to the voltage detection unit 3041 and the second trigger unit 3052 respectively.

[0055] The third comparison unit 3042 is used to detect the target voltage of the over-temperature, over-voltage and over-current protection circuit through the voltage detection unit 304, and when it is detected that the voltage value of the target voltage exceeds the preset voltage value, send a third protection signal to the second trigger unit 3052. For example, when the target voltage exceeds the preset voltage value, the third comparison unit 3042 switches from the off state to the on state, so that the second trigger unit 2052 receives a low level signal as the third protection signal.

[0056] based on Figure 4 The schematic diagram shown is Figure 5 As shown, it is a structural schematic diagram of an over-temperature over-voltage over-current protection circuit provided by an embodiment of the present application, the voltage detection unit 3041 includes: an eighth resistor R8, a ninth resistor R9, and the third comparison unit 3042 includes: a tenth resistor R10, a second capacitor C2 and a first three-terminal regulator U1. Among them, the first end of the eighth resistor R8 is connected to the detection terminal V, the second end of the eighth resistor R8 is respectively connected to the first end of the second capacitor C2, the first end of the first three-terminal regulator U1, and the first end of the ninth resistor R9, the second end of the second capacitor C2 is connected to the first end of the tenth resistor R10, the second end of the tenth resistor R10 is respectively connected to the second trigger unit 3052 and the second end of the first three-terminal regulator U1, and the third end of the first three-terminal regulator U1 is connected to the second end of the ninth resistor R9 and then grounded.

[0057] In this embodiment, when the voltage value of the target voltage continues to increase to exceed the preset voltage value, when the voltage value of the voltage of the ninth resistor R9 exceeds the target voltage value corresponding to the first three-terminal regulator U1, the first three-terminal regulator U1 switches to the on state, thereby sending a low-level signal to the second trigger unit 3052 as the third protection signal.

[0058] The over-temperature, over-voltage and over-current protection circuit provided by the present application includes: a control module, a temperature detection module, a current detection module, a voltage detection module, and a protection trigger module including a first trigger unit and a second trigger unit. The protection trigger module is used to switch to a protection mode to protect the circuit when the temperature value of the target temperature detected by the temperature detection module exceeds a preset temperature value, or the current value of the target current detected by the current detection module exceeds a preset current value, or the voltage value of the target voltage detected by the voltage detection module exceeds a preset voltage value. The protection circuit provided by the present application has a high degree of integration, and only one port of the control module is required to realize over-temperature, over-voltage and over-current protection, which reduces the volume and weight of the entire circuit, and is suitable for use in some devices that need to be light and portable, reducing the increase in manufacturing costs and improving the practicality and economy of the protection circuit.

[0059] like Figure 6 As shown, it is a schematic diagram of the structure of a temperature overvoltage overcurrent protection circuit provided by an embodiment of the present application, including: a control module 401, a temperature detection module 402, a current detection module 403, a voltage detection module 404, a protection trigger module 405 including a first trigger unit 4051 and a second trigger unit 4052, and a reference module 406. The connection structure of the control module 401 and the temperature detection module 402 is shown in the above Figure 3 , voltage detection module 404 see above Figure 5 , I will not go into details here.

[0060] In this embodiment, the first trigger unit 4052 includes: an eleventh resistor R11, a twelfth resistor R12 and a transistor Q, and the second trigger unit 4051 includes: an optocoupler diode PCIA, an optocoupler transistor PCIB, a thirteenth resistor R13 and a fourteenth resistor R14.

[0061] The first end of the eleventh resistor R11 is respectively connected to the cathode of the first diode D1 in the temperature detection module 401 and the cathode of the second diode D2 in the current detection module 403, the second end of the eleventh resistor R11 is respectively connected to the first end of the twelfth resistor R12 and the base of the transistor Q, the emitter of the transistor Q is connected to the second end of the twelfth resistor R12 and then grounded, the collector of the transistor Q is respectively connected to the cathode of the optocoupler diode PCIA and the first end of the fourteenth resistor R14, the anode of the optocoupler diode PCIA is respectively connected to the second end of the fourteenth resistor R14 and the first end of the thirteenth resistor R13, the second end of the thirteenth resistor R13 is connected to the detection terminal V, the base of the optocoupler transistor PCIB is connected to the optocoupler diode PCIA, and the collector and emitter of the optocoupler transistor PCIB are respectively connected to the control module 401.

[0062] The reference module 406 includes: a fifteenth resistor R15, a second three-terminal voltage regulator U2 and a third capacitor C3. The first end of the fifteenth resistor R15 is connected to the detection terminal V, the second end of the fifteenth resistor R15 is respectively connected to the first end of the second three-terminal voltage regulator U2, the second end of the second three-terminal voltage regulator U2, the first end of the third capacitor C3, the temperature detection module 402 and the current detection module 403, and the third end of the second three-terminal voltage regulator U2 is connected to the second end of the third capacitor C3 and then grounded. Specifically, the first end of the fifteenth resistor R15 is connected to the detection terminal V, the second end of the fifteenth resistor R15 is respectively connected to the first end of the second three-terminal voltage regulator U2, the second end of the second three-terminal voltage regulator U2, the first end of the third capacitor C3, the second end of the third resistor R3 in the temperature detection module 402 and the second end of the seventh resistor R7 in the current detection module 403, and the third end of the second three-terminal voltage regulator U2 is connected to the third capacitor C3 and then grounded.

[0063] The control module 401 includes: a control unit 4011 and a sixteenth resistor R16. The base of the optocoupler transistor PCIB is connected to the second trigger unit 4052, the collector of the optocoupler transistor PCIB is connected to the first end of the sixteenth resistor R16, the emitter of the optocoupler transistor PCIB is connected to the first end of the control unit 4012, and the second end of the sixteenth resistor R16 is connected to the second end of the control unit 4011.

[0064] In this embodiment, the resistance of the thermistor NTC decreases as the temperature decreases. When the target temperature exceeds the preset temperature value, the resistance of the thermistor NTC decreases below the target resistance value. Based on the low resistance value of the thermistor NTC, a high voltage is input to the non-inverting input terminal of the first operational amplifier comparator U1A. Further, the first operational amplifier comparator U1A outputs a high level signal to the base and emitter of the transistor Q as a first protection signal based on the reference voltage.

[0065] The voltage value of the voltage of the fifth resistor R5 increases with the increase of the target current. When the current value of the target current exceeds the preset current value, the voltage value of the voltage of the fifth resistor R5 increases to above the target voltage value. Based on the high voltage input to the non-inverting input terminal of the second operational amplifier comparator U1B, the second operational amplifier comparator U1B further outputs a high-level signal to the base and emitter of the transistor Q based on the reference voltage as a second protection signal.

[0066] When the voltage value of the target voltage continues to increase to exceed the preset voltage value, when the voltage value of the voltage of the ninth resistor R9 exceeds the target voltage value corresponding to the first three-terminal regulator U1, the first three-terminal regulator U1 switches to the on state, thereby sending a low-level signal to the second trigger unit 3052 as the third protection signal.

[0067] After receiving the high-level signal, the transistor Q switches from the off state to the on state, and the cathode of the optocoupler diode PCIA receives a low-level signal as the first trigger signal, or receives a third protection signal of a low-level signal, so that the optocoupler diode PCIA emits light and sends an optical signal to the control module 401 as the second trigger signal, so that the optocoupler transistor PCIB included in the control module 401 sends a level signal to the control unit 4011 based on the optical signal, and the control unit 4011 protects the target circuit including the over-temperature, over-voltage and over-current protection circuit, such as shutting off the power supply of the target circuit.

[0068] The over-temperature, over-voltage and over-current protection circuit provided by the present application includes: a control module, a temperature detection module, a current detection module, a voltage detection module, and a protection trigger module including a first trigger unit and a second trigger unit. The protection trigger module is used to switch to a protection mode to protect the circuit when the temperature value of the target temperature detected by the temperature detection module exceeds a preset temperature value, or the current value of the target current detected by the current detection module exceeds a preset current value, or the voltage value of the target voltage detected by the voltage detection module exceeds a preset voltage value. The protection circuit provided by the present application has a high degree of integration, and only one port of the control module is required to realize over-temperature, over-voltage and over-current protection, which reduces the volume and weight of the entire circuit, and is suitable for use in some devices that need to be light and portable, reducing the increase in manufacturing costs and improving the practicality and economy of the protection circuit.

[0069] In one embodiment, the present application also provides a circuit board, the circuit board comprising: Figure 1 - Figure 6 Any over-temperature, over-voltage and over-current protection circuit shown. It can be understood that the circuit board provided in the embodiment of the present application can be a whole circuit board, or can be formed by splicing multiple circuit boards.

[0070] The over-temperature, over-voltage and over-current protection circuit provided by the present application includes: a control module, a temperature detection module, a current detection module, a voltage detection module, and a protection trigger module including a first trigger unit and a second trigger unit. The protection trigger module is used to switch to a protection mode to protect the circuit when the temperature value of the target temperature detected by the temperature detection module exceeds a preset temperature value, or the current value of the target current detected by the current detection module exceeds a preset current value, or the voltage value of the target voltage detected by the voltage detection module exceeds a preset voltage value. The protection circuit provided by the present application has a high degree of integration, and only one port of the control module is required to realize over-temperature, over-voltage and over-current protection, which reduces the volume and weight of the entire circuit, and is suitable for use in some devices that need to be light and portable, reducing the increase in manufacturing costs and improving the practicality and economy of the protection circuit.

[0071] The above disclosure is only the preferred embodiment of the present application, which certainly cannot be used to limit the scope of rights of the present application. Therefore, equivalent changes made according to the claims of the present application are still within the scope covered by the present application.

Claims

1. An over-temperature, over-voltage and over-current protection circuit, characterized in that: The over-temperature, over-voltage and over-current protection circuit comprises: A control module, a temperature detection module, a current detection module, a voltage detection module, and a protection trigger module including a first trigger unit and a second trigger unit; The temperature detection module and the current detection module are electrically connected to the first trigger unit respectively, the first trigger unit and the voltage detection module are electrically connected to the second trigger unit respectively, and the second trigger unit is electrically connected to the control module; The temperature detection module is used to detect the target temperature of the over-temperature, over-voltage and over-current protection circuit, and send a first protection signal to the first trigger unit when the temperature value of the target temperature exceeds a preset temperature value; The current detection module is used to detect the target current of the over-temperature, over-voltage and over-current protection circuit, and send a second protection signal to the first trigger unit when the current value of the target current exceeds a preset current value; The voltage detection module is used to detect the target voltage of the over-temperature, over-voltage and over-current protection circuit, and send a third protection signal to the second trigger unit when the voltage value of the target voltage exceeds a preset voltage value; The first trigger unit is configured to send a first trigger signal to the second trigger unit upon receiving the first protection signal or the second protection signal; The second trigger unit is configured to send a second trigger signal to the control module upon receiving the first trigger signal or the third protection signal; The control module is used to switch to the protection mode when receiving the second trigger signal.

2. The over-temperature, over-voltage and over-current protection circuit according to claim 1, characterized in that: The over-temperature, over-voltage and over-current protection circuit further includes: a reference module; The reference module is electrically connected to the temperature detection module and the current detection module respectively; The reference module provides reference voltages to the temperature detection module and the current detection module respectively.

3. The over-temperature, over-voltage and over-current protection circuit according to claim 2, characterized in that: The temperature detection module includes: a temperature detection unit and a first comparison unit; The first comparison unit is connected to the temperature detection unit, the reference module and the first trigger unit respectively; The first comparison unit is used to detect the target temperature of the over-temperature, over-voltage and over-current protection circuit through the temperature detection unit, and send the first protection signal to the first trigger unit when the temperature value of the target temperature exceeds a preset temperature value.

4. The over-temperature, over-voltage and over-current protection circuit according to claim 3, characterized in that: The temperature detection unit includes: a thermistor, and the first comparison unit includes: a first resistor, a second resistor, a third resistor, a fourth resistor, a first operational amplifier comparator and a first diode; The first end of the thermistor is connected to the detection end, the second end of the thermistor is connected to the first end of the first resistor, the second end of the first resistor is respectively connected to the first end of the second resistor and the non-inverting input end of the first operational amplifier comparator, the second end of the second resistor is grounded, the first end of the third resistor is respectively connected to the inverting input end of the first operational amplifier comparator and the first end of the fourth resistor, the second end of the third resistor is connected to the reference module, the second end of the fourth resistor is grounded, the output end of the first operational amplifier comparator is connected to the positive electrode of the first diode, and the negative electrode of the first diode is connected to the first trigger unit.

5. The over-temperature, over-voltage and over-current protection circuit according to claim 2, characterized in that: The current detection module includes: a second comparison unit and a current detection unit; The second comparison unit is connected to the current detection unit, the reference module and the first trigger unit respectively; The second comparison unit is used to detect the target current of the over-temperature, over-voltage and over-current protection circuit through the current detection unit, and send the second protection signal to the first trigger unit when the current value of the target current exceeds a preset current value.

6. The over-temperature, over-voltage and over-current protection circuit according to claim 5, characterized in that: The current detection unit includes: a fifth resistor, and the second comparison unit includes: a sixth resistor, a seventh resistor, a first capacitor, a second operational amplifier comparator and a second diode; The first end of the sixth resistor is grounded, the second end of the sixth resistor is respectively connected to the first end of the seventh resistor, the inverting input end of the second operational amplifier comparator, and the first end of the first capacitor, the second end of the seventh resistor is connected to the reference module, the first end of the fifth resistor is connected to the current detection end, the second end of the fifth resistor is connected to the non-inverting input end of the second operational amplifier comparator, the output end of the second operational amplifier comparator is respectively connected to the second end of the first capacitor and the positive electrode of the second diode, and the negative electrode of the second diode is connected to the first trigger unit.

7. The over-temperature, over-voltage and over-current protection circuit according to claim 1, characterized in that: The voltage detection module includes: a voltage detection unit and a third comparison unit; The third comparison unit is connected to the voltage detection unit and the second trigger unit respectively; The third comparison unit sends the third protection signal to the second trigger unit when the voltage value of the target voltage exceeds a preset voltage value.

8. The over-temperature, over-voltage and over-current protection circuit according to claim 7, characterized in that: The voltage detection unit includes: an eighth resistor and a ninth resistor, and the third comparison unit includes: a tenth resistor, a second capacitor and a first three-terminal regulator; The first end of the eighth resistor is connected to the detection end, the second end of the eighth resistor is respectively connected to the first end of the second capacitor, the first end of the first three-terminal regulator, and the first end of the ninth resistor, the second end of the second capacitor is connected to the first end of the tenth resistor, the second end of the tenth resistor is respectively connected to the second trigger unit and the second end of the first three-terminal regulator, and the third end of the first three-terminal regulator is connected to the second end of the ninth resistor and then grounded.

9. The over-temperature, over-voltage and over-current protection circuit according to claim 1, characterized in that: The first trigger unit includes: an eleventh resistor, a twelfth resistor and a transistor, and the second trigger unit includes: an optical coupling diode, an optical coupling transistor, a thirteenth resistor and a fourteenth resistor; The first end of the eleventh resistor is respectively connected to the temperature detection module and the current detection module, the second end of the eleventh resistor is respectively connected to the first end of the twelfth resistor and the base of the transistor, the emitter of the transistor is connected to the second end of the twelfth resistor and then grounded, the collector of the transistor is respectively connected to the negative electrode of the optocoupler diode and the first end of the fourteenth resistor, the positive electrode of the optocoupler diode is respectively connected to the second end of the fourteenth resistor and the first end of the thirteenth resistor, the second end of the thirteenth resistor is connected to the detection end, the base of the optocoupler transistor is connected to the optocoupler diode, and the collector and emitter of the optocoupler transistor are respectively connected to the control module.

10. The over-temperature, over-voltage and over-current protection circuit according to claim 2, characterized in that: The reference module includes: a fifteenth resistor, a second three-terminal regulator and a third capacitor; The first end of the fifteenth resistor is connected to the detection end, the second end of the fifteenth resistor is respectively connected to the first end of the second three-terminal regulator, the second end of the second three-terminal regulator, the first end of the third capacitor, the temperature detection module and the current detection module, and the third end of the second three-terminal regulator is connected to the second end of the third capacitor and then grounded.

11. The over-temperature, over-voltage and over-current protection circuit according to claim 9, characterized in that: The control module includes: a control unit and a sixteenth resistor; The collector of the optocoupler transistor is connected to the first end of the sixteenth resistor, and the second end of the sixteenth resistor is connected to the second end of the control unit.

12. A circuit board, characterized in that: The circuit board includes the over-temperature, over-voltage and over-current protection circuit as described in any one of claims 1-11.

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