Temperature fault detection circuit, detection method and converter

Abstract

The invention discloses a temperature fault detection circuit, a detection method and a converter, and the circuit comprises a plurality of temperature sampling circuits which are used for correspondingly collecting the temperatures of a plurality of target electronic devices, and outputting a plurality of corresponding temperature sampling signals; the temperature comparison circuit is used for comparing the plurality of temperature sampling signals and outputting a temperature detection signal with the highest temperature value in the plurality of temperature sampling signals; and the control circuit is used for determining that at least one of the multiple target electronic devices has a temperature fault when the temperature value corresponding to the temperature detection signal is not less than a preset temperature value. The technical scheme of the invention aims to realize temperature fault detection of a plurality of target electronic devices.

Description

Technical Field

[0001] The present invention relates to the field of temperature detection, and in particular to a temperature fault detection circuit, a detection method and a converter. Background Art

[0002] In current converter solutions, electronic devices with the highest simulated temperature or heat sink points with poor heat dissipation are usually used as monitoring points for the temperature of electronic devices. The electronic device may be an IGBT module. Monitoring only one point for multiple IGBT temperatures will cause the working status of the remaining IGBTs to be uncontrollable. When the remaining IGBTs become abnormal and the temperature is too high, it cannot be detected in time, thus affecting the service life of the IGBT and the working status of the equipment. Summary of the invention

[0003] The main purpose of the present invention is to provide a temperature fault detection circuit, a detection method and a converter, which are intended to realize temperature fault detection of multiple target electronic devices.

[0004] To achieve the above object, the present invention proposes a temperature fault detection circuit comprising:

[0005] A plurality of temperature sampling circuits, wherein the plurality of temperature sampling circuits are used to correspondingly collect temperatures of a plurality of target electronic devices and output a plurality of corresponding temperature sampling signals;

[0006] a temperature comparison circuit, used for comparing the plurality of temperature sampling signals and outputting a temperature detection signal having the highest temperature value among the plurality of temperature sampling signals; and

[0007] The control circuit is used to determine that at least one of the multiple target electronic components has a temperature fault when the temperature value corresponding to the temperature detection signal is not less than a preset temperature value.

[0008] Optionally, the temperature sampling circuit includes a first resistor and a negative temperature coefficient thermistor, the first end of the first resistor is used to access the power supply voltage, the second end of the first resistor is connected to the first end of the negative temperature coefficient thermistor and to the input end of the temperature comparison circuit, and the second end of the negative temperature coefficient thermistor is grounded;

[0009] The temperature comparison circuit includes a multi-way comparison unit and a DC power supply end. The output ends of the multi-way comparison unit are connected to each other and to the DC power supply end, and serve as the output end of the temperature comparison circuit.

[0010] Optionally, the comparison unit includes a first comparator, which has a non-phase input terminal, an inverting input terminal and an output terminal, the non-phase input terminal of the first comparator is connected to the output terminal of the temperature sampling circuit, the inverting input terminal of the first comparator and the output terminal of the first comparator are interconnected with the DC power supply terminal and serve as the output terminal of the comparison unit.

[0011] Optionally, the temperature sampling circuit includes a first resistor and a positive temperature coefficient thermistor, the first end of the first resistor is used to access the power supply voltage, the second end of the first resistor is connected to the first end of the positive temperature coefficient thermistor and to the input end of the temperature comparison circuit, and the second end of the positive temperature coefficient thermistor is grounded;

[0012] The temperature comparison circuit includes a plurality of comparison units, the plurality of comparison units are connected one-to-one with a plurality of the temperature sampling circuits, and the output ends of the plurality of comparison units are connected to each other and serve as the output ends of the temperature comparison circuit.

[0013] Optionally, the comparison unit includes a first comparator, which has a non-phase input terminal, an inverting input terminal and an output terminal, the non-phase input terminal of the first comparator is connected to the output terminal of the temperature sampling circuit, the inverting input terminal of the first comparator and the output terminal of the first comparator are connected to each other and serve as the output terminal of the comparison unit.

[0014] Optionally, the temperature comparison circuit also includes a single-phase output element, and the single-phase output element is connected between the output end of each comparison unit and the control circuit; the single-phase output element is used to isolate the output signals of the comparison units in other paths from flowing back to the comparison unit where the single-phase output element is located.

[0015] Optionally, the temperature fault detection circuit further includes:

[0016] A step-down circuit is provided in series between the temperature comparison circuit and the control circuit, and is used for stepping down the temperature comparison signal output by the temperature comparison circuit and outputting the result to the control circuit.

[0017] Optionally, the step-down circuit includes a seventh resistor and an eighth resistor, the first end of the seventh resistor is connected to the output end of the temperature comparison circuit, the second end of the seventh resistor is connected to the first end of the eighth resistor and to the input end of the control circuit, and the second end of the eighth resistor is grounded.

[0018] Optionally, the temperature fault detection circuit further includes:

[0019] A follower circuit is provided in series between the temperature comparison circuit and the control circuit, and is used for isolating and impedance matching the temperature comparison signal output by the temperature comparison circuit and then outputting it to the control circuit.

[0020] Optionally, the follower circuit includes a first operational amplifier, which has a non-phase input terminal, an inverting input terminal and an output terminal, the non-phase input terminal of the first operational amplifier is connected to the output terminal of the temperature comparison circuit, and the inverting input terminal of the first operational amplifier and the output terminal of the first operational amplifier are interconnected with the output terminal of the control circuit.

[0021] Optionally, the temperature fault detection circuit further includes:

[0022] A display, wherein a controlled end of the display is connected to an output end of the control circuit, and the control circuit is also used to control the display to display the highest temperature value among the multiple target electronic devices when the temperature value corresponding to the temperature detection signal is less than a preset temperature value.

[0023] Optionally, the temperature fault detection circuit further includes:

[0024] A connection fault detection circuit, wherein the input end of the connection fault detection circuit is connected to the plurality of temperature sampling circuits, the output end of the connection fault detection circuit is connected to the input end of the control circuit, and the connection fault detection circuit is used to output a connection fault detection signal to the control circuit when the voltage value corresponding to any temperature sampling signal is lower than a preset voltage value;

[0025] The control circuit is further configured to determine, based on the connection fault detection signal, that a connection fault exists in at least one of the plurality of target electronic devices.

[0026] Optionally, the connection fault detection circuit includes multiple second comparators, each of which has a non-phase input terminal, an inverting input terminal and an output terminal. The inverting input terminals of the multiple second comparators are connected one-to-one to the output terminals of the multiple temperature sampling circuits. The non-phase input terminals of the multiple second comparators are used to access a reference voltage. The output terminals of the multiple second comparators are connected to each other and to the input terminal of the control circuit.

[0027] Optionally, the connection fault detection circuit further includes multiple second comparators, a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, a first switch tube and a second switch tube, the second comparator has a non-phase input terminal, an inverting input terminal and an output terminal, the inverting input terminals of the multiple second comparators are connected one-to-one with the output terminals of the multiple temperature sampling circuits, the non-phase input terminals of the multiple second comparators are used to access a reference voltage, the first end of the third resistor is used to access a power supply voltage, the second end of the third resistor, the first end of the fourth resistor and the output terminals of the multiple second comparators are connected to each other, the second end of the fourth resistor, the first end of the fifth resistor and the base of the first switch tube are connected to each other, the collector of the first switch tube, the first end of the sixth resistor and the gate of the second switch tube are connected to each other, the second end of the sixth resistor is used to access the power supply voltage, the drain of the second switch tube is connected to the output terminal of the temperature comparison circuit, and the second end of the fifth resistor, the emitter of the first switch tube and the source of the second switch tube are grounded.

[0028] Optionally, the temperature fault detection circuit further includes:

[0029] A first isolation circuit, wherein the first isolation circuit is arranged in series between the temperature comparison circuit and the control circuit; and / or,

[0030] a second isolation circuit, the second isolation circuit being arranged in series between the connection fault detection circuit and the control circuit;

[0031] The first isolation circuit is used to isolate and transform the temperature comparison signal output by the temperature comparison circuit and then output it to the control circuit;

[0032] The second isolation circuit is used to isolate and transform the fault detection signal output by the connection fault detection circuit and then output it to the control circuit.

[0033] The present invention also provides a method for detecting temperature faults of multiple electronic devices, comprising the following steps:

[0034] Collecting the temperatures of multiple target electronic devices and outputting corresponding multiple temperature sampling signals;

[0035] Comparing the plurality of temperature sampling signals, and outputting a temperature detection signal having the highest temperature value among the plurality of temperature sampling signals;

[0036] When the temperature value corresponding to the temperature detection signal is not less than a preset temperature value, it is determined that at least one of the plurality of target electronic components has a temperature fault.

[0037] The present invention further provides a converter, comprising the temperature fault detection circuit as described above or using the temperature fault detection method of multiple electronic devices as described above.

[0038] The technical solution of the present invention forms a temperature fault detection circuit through multiple temperature sampling circuits, temperature comparison circuits and control circuits, wherein the multiple temperature sampling circuits are used to collect the temperatures of multiple target electronic devices and output corresponding multiple temperature sampling signals; the temperature comparison circuit is used to compare the multiple temperature sampling signals and output the temperature detection signal with the highest temperature value among the multiple temperature sampling signals; and the control circuit is used to determine that at least one of the multiple target electronic devices has a temperature fault when the temperature value corresponding to the temperature detection signal is not less than the preset temperature value. In this way, the temperature detection circuit of this scheme can compare the temperatures of multiple target electronic devices and output an alarm signal according to the comparison results of the multiple temperature sampling signals to detect the temperatures of multiple target electronic devices and perform corresponding functions according to the temperatures of multiple target electronic devices. The present invention aims to realize temperature fault detection of multiple target electronic devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the embodiments of the present invention 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 invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0040] Figure 1 It is a functional module diagram of an embodiment of a temperature fault detection circuit of the present invention;

[0041] Figure 2 A schematic diagram of functional modules of another embodiment of a temperature fault detection circuit of the present invention;

[0042] Figure 3 A schematic diagram of the circuit structure of an embodiment of a temperature fault detection circuit of the present invention;

[0043] Figure 4 A schematic diagram of the circuit structure of another embodiment of the temperature fault detection circuit of the present invention;

[0044] Figure 5 A schematic diagram of the circuit structure of another embodiment of the temperature fault detection circuit of the present invention;

[0045] Figure 6 The figure is a circuit structure diagram of another embodiment of the temperature fault detection circuit of the present invention.

[0046] Description of Figure Numbers:

[0047] Label name Label name 10 Temperature sampling circuit UA Second comparator 20 Temperature Comparator Circuit UB First operational amplifier 30 Control Circuit D Single-phase output element 40 Connection Fault Detection Circuit V Supply voltage 50 First isolation circuit Vref Reference voltage 60 Second isolation circuit Q1 The first switch NTC Negative Temperature Coefficient Thermistor Q2 The second switch PTC Positive Temperature Coefficient Thermistor R1~R8 The first resistor to the eighth resistor U First comparator

[0048] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0049] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0050] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0051] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or suggesting their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0052] The present invention provides a temperature fault detection circuit which can be applied to a converter.

[0053] The inverter usually includes multiple target electronic devices that need to detect temperature. The target electronic device can be an IGBT module. The IGBT with the highest temperature or the heat sink with poor heat dissipation is used as the monitoring point of the IGBT module temperature. In actual applications, there may be unexpected situations that cause the temperature of an IGBT module that is not a monitoring point to suddenly rise, such as when the IGBT module is short-circuited. In this way, the solution of only detecting the temperature of one IGBT module cannot comprehensively monitor and detect the temperatures of multiple IGBT modules.

[0054] Reference Figure 1 In one embodiment of the present invention, the temperature fault detection circuit includes:

[0055] A plurality of temperature sampling circuits 10, wherein the plurality of temperature sampling circuits 10 are used to correspondingly collect temperatures of a plurality of target electronic devices and output a plurality of corresponding temperature sampling signals;

[0056] A temperature comparison circuit 20, used for comparing the plurality of temperature sampling signals and outputting a temperature detection signal having the highest temperature value among the plurality of temperature sampling signals; and

[0057] The control circuit 30 is used to determine that at least one of the multiple target electronic components has a temperature fault when the temperature value corresponding to the temperature detection signal is not less than a preset temperature value.

[0058] In this embodiment, the temperature sampling circuit 10 may be composed of electronic components such as a temperature detection chip or a temperature detection element and a resistor, and the temperature detection element may be a thermocouple, a thermal resistor or a thermistor, etc. The electronic device may be an IGBT module in the converter, and the temperature detection element in the temperature sampling circuit 10 is connected to the electronic device or is arranged on the electronic device, and can collect the temperature signal of the electronic device and output a voltage signal corresponding to the temperature of the electronic device, that is, a temperature sampling signal to the temperature comparison circuit 20.

[0059] In this embodiment, the temperature comparison circuit 20 can be implemented by a chip integrating multiple comparators, or by multiple discrete comparators. The temperature comparison circuit 20 can receive multiple temperature sampling signals output by multiple temperature sampling circuits 10, compare the multiple temperature sampling signals, and obtain the temperature sampling signal with the highest temperature value; the temperature sampling signal can be a voltage signal, and the temperature comparison circuit 20 can obtain the temperature sampling signal with the highest temperature value by comparing the voltage value of the voltage signal, and then output the temperature comparison signal. The corresponding relationship between the voltage value of the temperature sampling signal and the temperature value is determined by the specific structure of the temperature sampling circuit 10; for example, the higher the temperature of the target electronic device sampled by the temperature sampling circuit 10, the lower the voltage value of the output temperature sampling signal, then the temperature comparison circuit 20 compares the temperature sampling signal with the lowest voltage value among the multiple temperature sampling signals, that is, the temperature sampling signal with the highest temperature value, and then outputs the temperature sampling signal with the highest temperature value as the temperature comparison signal to the control circuit 30. On the contrary, if the temperature sampling circuit 10 samples the target electronic device at a higher temperature, the higher the voltage value of the output temperature sampling signal is, then the temperature comparison circuit 20 compares the temperature sampling signal with the highest voltage value among the multiple temperature sampling signals, that is, the temperature sampling signal with the highest temperature value, and outputs the temperature sampling signal with the highest temperature value as the temperature comparison signal to the control circuit 30. The temperature comparison circuit 20 can set the comparison standard according to the user's needs, compare the temperature values ​​represented by the multiple temperature sampling signals, and output the temperature comparison signal. For example, if the user's needs are to prevent the electronic device from being overheated and affecting the normal operation of the electronic device, the temperature sampling signal with the highest temperature value can be obtained by the temperature comparison circuit 20 and then output to the control circuit 30. It should be noted that the voltage signal output by the temperature sampling signal to the temperature comparison circuit 20 is related to the characteristics of the temperature detection element. For example, the thermistor includes a negative temperature coefficient thermistor NTC and a positive temperature coefficient thermistor PTC. The higher the temperature of the negative temperature coefficient thermistor NTC, the lower the resistance value, and the lower the temperature sampling signal voltage output by the temperature sampling circuit 10; the higher the temperature of the positive temperature coefficient thermistor PTC, the higher the resistance value, and the higher the temperature sampling signal voltage output by the temperature sampling circuit 10. Therefore, for the temperature sampling circuit 10 composed of different temperature detection elements, the temperature comparison circuit 20 can set corresponding comparison standards. For example, for the temperature sampling circuit 10 composed of NTC thermistor, the comparison circuit can compare the temperature sampling signal with the lowest voltage, so that the temperature sampling signal with the lowest voltage represents the electronic device with the highest temperature value; and for the temperature sampling circuit 10 composed of PTC thermistor, the comparison circuit can compare the temperature sampling signal with the highest voltage, so that the temperature sampling signal with the highest voltage represents the electronic device with the highest temperature value.

[0060] The control circuit 30 can be composed of a digital signal control circuit 30 (Digital Signal Processor, referred to as DSP), a microcontroller circuit 30, an MCU single chip or other electronic components. The control circuit 30 can receive a temperature comparison signal, convert and obtain a specific temperature value, and then output an alarm signal according to the temperature value. The standard for the control circuit 30 to output the alarm signal can be set according to user needs; for example, the control circuit 30 can receive a temperature comparison signal output by the temperature comparison circuit 20, and the temperature comparison signal output by the temperature comparison circuit 20 can be a temperature signal representing the target electronic device with the highest temperature value. The control circuit 30 can convert the temperature comparison signal into a corresponding voltage value, and then compare the voltage value representing the highest temperature value with a preset temperature threshold. If the voltage value representing the highest temperature value is greater than the preset temperature threshold, it means that the temperature of the target electronic device is too high, which will affect the working state of the target electronic device and the service life of the target electronic device. At this time, the control circuit 30 can output an alarm signal; the alarm signal can be output to a peripheral alarm device to remind the staff that the temperature of the target electronic device is too high. The preset temperature threshold can be set according to the specific model and type of the target electronic device, and factors such as the working environment of the target electronic device can also be considered. In actual use, the control circuit can also limit the output power of the target electronic device through software control when the temperature of the target electronic device is too high, thereby reducing losses and lowering the temperature of the device; or the control circuit can also control the target electronic device through software to achieve protection.

[0061] The technical solution of the present invention forms a temperature fault detection circuit through multiple temperature sampling circuits 10, a temperature comparison circuit 20 and a control circuit 30, wherein the multiple temperature sampling circuits 10 are used to collect the temperatures of multiple target electronic devices and output corresponding multiple temperature sampling signals; the temperature comparison circuit 20 is used to compare the multiple temperature sampling signals and output a temperature detection signal with the highest temperature value among the multiple temperature sampling signals; and the control circuit 30 is used to determine that at least one of the multiple target electronic devices has a temperature fault when the temperature value corresponding to the temperature detection signal is not less than a preset temperature value. In this way, the temperature detection circuit of this solution can compare the temperatures of multiple target electronic devices and output an alarm signal according to the comparison results of the multiple temperature sampling signals to detect the temperatures of multiple target electronic devices and perform corresponding functions according to the temperatures of multiple target electronic devices. The present invention aims to realize temperature fault detection of multiple target electronic devices.

[0062] Reference Figure 3In one embodiment, the temperature sampling circuit 10 includes a first resistor R1 and a negative temperature coefficient thermistor NTC, the first end of the first resistor R1 is used to connect to the power supply voltage V, the second end of the first resistor R1 is connected to the first end of the negative temperature coefficient thermistor NTC, and is connected to the input end of the temperature comparison circuit 20, and the second end of the negative temperature coefficient thermistor NTC is grounded;

[0063] The temperature comparison circuit 20 includes a multi-way comparison unit and a DC power supply end. The output ends of the multi-way comparison unit are connected to each other and to the DC power supply end, and serve as the output end of the temperature comparison circuit 20 .

[0064] In this embodiment, the comparison unit can be implemented by a comparator or an integrated chip. In an exemplary technology, the comparison unit includes a first comparator U, which has a non-phase input terminal, an inverting input terminal and an output terminal. The non-phase input terminal of the first comparator U is connected to the output terminal of the temperature sampling circuit 10, and the inverting input terminal of the first comparator U and the output terminal of the first comparator U are interconnected with the DC power supply terminal and serve as the output terminal of the comparison unit.

[0065] In another exemplary technology, the temperature comparison circuit 20 may further include a second resistor R2, which is disposed between the DC power supply terminal and the output terminal of the multi-channel comparison unit. Figure 3 .

[0066] Furthermore, in this embodiment, a negative temperature coefficient thermistor NTC is used in the temperature sampling circuit 10, that is, a resistor whose resistance value decreases as the temperature increases; the structure of the temperature comparison circuit 20 is described by taking three first comparators U as an example; the three first comparators U are divided into U1, U2 and U3. The voltage division of the negative temperature coefficient thermistor NTC and the first resistor R1 is V*r2 / (r1+r2), where V represents the power supply voltage V of 5V, r1 represents the resistance value of the first resistor R1, and r2 represents the resistance value of the negative temperature coefficient thermistor NTC; in this embodiment, an operational amplifier can be used to act as a comparator. According to the working principle of the operational amplifier, the voltage at the inverting input terminal of U1 is V*r2 / (r1+r2), and the voltage at the output terminal of U1 is also V*r2 / (r1+r2). Since the output terminals of the three first comparators U1, U2 and U3 are connected together, if the target electronic device detected by the negative temperature coefficient thermistor NTC connected to U1 in the temperature sampling circuit 10 has the highest temperature, the output terminal voltage of U1 will be lower than the output terminal voltages of U2 and U3. Assuming that the 5V power supply voltage V is connected to the DC power supply terminal, the 5V power supply voltage V will be pulled down to the lowest voltage end of the three comparator output ports through the second resistor R2, that is, the output end of U1, and the voltage values ​​of U2 and U3 are greater than the voltage value of the first end of the second resistor R2. At this time, the lowest voltage of U1 will be output to the control circuit 30 of the next stage; the voltage signals output by the multiple comparators are compared by the 5V power supply voltage V through the second resistor R2, and three compared voltage signals can be obtained. Among them, the voltage signal with the smallest voltage represents the target electronic device with the highest temperature value, and the control circuit 30 can obtain the corresponding temperature value according to the output terminal voltage of the temperature sampling circuit 10.

[0067] Reference Figure 5 In one embodiment, the temperature sampling circuit 10 includes a first resistor R1 and a positive temperature coefficient thermistor PTC, the first end of the first resistor R1 is used to connect to the power supply voltage V, the second end of the first resistor R1 is connected to the first end of the positive temperature coefficient thermistor PTC, and is connected to the input end of the temperature comparison circuit 20, and the second end of the positive temperature coefficient thermistor PTC is grounded;

[0068] The temperature comparison circuit 20 includes multiple comparison units, which are connected one-to-one with the multiple temperature sampling circuits 10 . The output ends of the multiple comparison units are connected to each other and serve as the output ends of the temperature comparison circuit 20 .

[0069] In this embodiment, the comparison unit can be implemented by a comparator or an integrated chip. In an exemplary technology, the comparison unit includes a first comparator U, which has a non-phase input terminal, an inverting input terminal and an output terminal. The non-phase input terminal of the first comparator U is connected to the output terminal of the temperature sampling circuit 10, and the inverting input terminal of the first comparator U and the output terminal of the first comparator U are connected to each other and serve as the output terminal of the comparison unit.

[0070] Furthermore, in this embodiment, the temperature sampling circuit 10 uses a positive temperature coefficient thermistor PTC, that is, a resistor with a higher resistance value as the temperature increases, and the temperature comparison circuit 20 needs to make adaptive adjustments. For details, refer to Figure 5 . Take the temperature comparison circuit 20 composed of three first comparators U as an example for explanation; the three first comparators U are divided into U1, U2 and U3. The voltage division of the positive temperature coefficient thermistor PTC and the first resistor R1 is V*r2 / (r1+r2), where V represents the power supply voltage V of 5V, r1 represents the resistance value of the first resistor R1, and r2 represents the resistance value of the positive temperature coefficient thermistor PTC; in this embodiment, an operational amplifier can be used to play the role of a comparator. According to the working principle of the operational amplifier, the voltage at the inverting input terminal of U1 is V*r2 / (r1+r2), and the output terminal voltage of U1 is also V*r2 / (r1+r2). Since the output terminals of the three first comparators U1, U2 and U3 are connected together, if the target electronic device detected by the positive temperature coefficient thermistor PTC connected to U1 in the temperature sampling circuit 10 has the highest temperature, the output terminal voltage of U1 will be greater than the output terminal voltage of U2 and U3. At this time, the inverting input terminal voltage of U2 and U3 is V*r2 / (r1+r2), which is greater than the voltage of the non-inverting input terminal. Then the output voltage of U2 and U3 is 0, so the output terminal voltage of the temperature sampling circuit 10 is the maximum value voltage, which is output to the control circuit 30. In this way, the voltage signals output by multiple comparators are compared to obtain three compared voltage signals. The voltage signal with the largest voltage value represents the target electronic device with the highest temperature value, and the control circuit 30 can obtain the corresponding temperature value according to the output terminal voltage of the temperature sampling circuit 10.

[0071] Reference Figures 3 to 5 In one embodiment, the temperature comparison circuit 20 further includes a single-phase output element D, and the single-phase output element D is connected between the output end of each comparison unit and the control circuit 30; the single-phase output element D is used to isolate the output signals of the comparison units in other paths from flowing back to the comparison unit where the single-phase output element D is located.

[0072] In this embodiment, the single-phase output element D can be a diode, or other elements with an isolation function. The connection relationship of the single-phase output element D can be adjusted according to the type of thermistor in the temperature sampling circuit 10. For example, the temperature sampling circuit 10 uses a negative temperature coefficient thermistor NTC, then the cathode of the diode is connected to the output end of the comparison unit, and the anode of the diode is connected to the input end of the control circuit 30. For details, please refer to Figure 3 and Figure 4 For example, the temperature sampling circuit 10 uses a positive temperature coefficient thermistor PTC, then the anode of the diode is connected to the output end of the comparison unit, and the cathode of the diode is connected to the input end of the control circuit 30. For details, please refer to Figure 5 The single-phase output element D mainly plays the role of isolation and screening to prevent the outputs of the three comparators from crosstalking with each other.

[0073] In combination with the above embodiment, when the temperature sampling circuit 10 adopts a negative temperature coefficient thermistor NTC, three single-phase output elements D are set corresponding to the three first comparators U in the above embodiment, namely D1, D2 and D3. At this time, the output terminal voltages of U2 and U3 cannot be output to the subsequent control circuit 30 through the single-phase output element D, and only the lowest voltage value of U1 will be output to the subsequent control circuit 30.

[0074] When the temperature sampling circuit 10 uses a positive temperature coefficient thermistor PTC, due to the isolation effect of the single-phase output element D, the output voltages of U2 and U3 will not affect the output terminal voltage of the temperature sampling circuit 10 .

[0075] Therefore, the single-phase output element D is provided in this embodiment to isolate the output signals of the comparison units in other paths from flowing back to the comparison unit where the single-phase output element D is located, so that the comparison result of the temperature comparison circuit 20 will not be affected.

[0076] Reference Figures 3 to 5 In one embodiment, the temperature fault detection circuit further includes:

[0077] A step-down circuit is provided in series between the temperature comparison circuit 20 and the control circuit 30 , and is used for stepping down the temperature comparison signal output by the temperature comparison circuit 20 and outputting the result to the control circuit 30 .

[0078] In this embodiment, in order to prevent the voltage value of the temperature comparison signal from being too high and causing the control circuit 30 to be unable to receive and process it normally, a step-down circuit can be set to step down the temperature comparison signal output by the temperature comparison circuit 20, such as stepping down the voltage value of the temperature comparison signal to a voltage range of 0V to 3V. In this way, the control circuit 30 can process the temperature comparison signal and will not cause abnormal operation of the control circuit 30 due to excessive voltage. The specific voltage division ratio and the voltage range of the voltage division can be determined according to the voltage range that the control circuit 30 can receive and process, and the voltage range that the control circuit 30 can receive and process can be determined by the specific model of the control circuit 30.

[0079] Reference Figures 3 to 5 In one embodiment, the step-down circuit includes a seventh resistor R7 and an eighth resistor R8, the first end of the seventh resistor R7 is connected to the output end of the temperature comparison circuit 20, the second end of the seventh resistor R7 is connected to the first end of the eighth resistor R8, and is connected to the input end of the control circuit 30, and the second end of the eighth resistor R8 is grounded.

[0080] In this embodiment, the step-down circuit can be composed of a seventh resistor R7 and an eighth resistor R8. After the voltage is divided by the seventh resistor R7 and the eighth resistor R8, the voltage value output to the control circuit 30 can be reduced. The voltage division ratio of the step-down circuit can be determined by setting the resistance values ​​of the eighth resistor R8 and the ninth resistor, and the specific voltage division ratio that needs to be set for the step-down circuit can be determined by the voltage range of the temperature comparison signal and the voltage range that the control circuit 30 can handle; the specific structure of the step-down circuit can also be adjusted according to actual needs.

[0081] Reference Figures 3 to 5 In one embodiment, the temperature fault detection circuit further includes:

[0082] A follower circuit is provided in series between the temperature comparison circuit 20 and the control circuit 30 , and is used for isolating and impedance matching the temperature comparison signal output by the temperature comparison circuit 20 and then outputting it to the control circuit 30 .

[0083] In this embodiment, the follower circuit can be composed of an operational amplifier. Since the input impedance of the operational amplifier is high and the output impedance is low, the operational amplifier can be used as a buffer stage and an isolation stage. Because the temperature comparison circuit 20 of the previous stage can use an amplifier to compare the voltage value, and the output impedance of the operational amplifier is generally relatively high, usually in the thousands of ohms to tens of thousands of ohms, if the input impedance of the subsequent stage is relatively small, then a considerable part of the signal will be lost in the output resistance of the previous stage. At this time, an operational amplifier can be set to perform isolation and buffering, which plays a role in connecting the upper and lower stages. In addition, the operational amplifier can also isolate the signal output by the temperature comparison circuit 20, and protect the control circuit 30 of the subsequent stage.

[0084] Furthermore, in one embodiment, the follower circuit includes a first operational amplifier UB, the first operational amplifier UB having a non-phase input terminal, an inverting input terminal and an output terminal, the non-phase input terminal of the first operational amplifier UB is connected to the output terminal of the temperature comparison circuit 20, and the inverting input terminal of the first operational amplifier UB and the output terminal of the first operational amplifier UB are interconnected with the output terminal of the control circuit 30.

[0085] In this embodiment, the follower circuit may use an operational amplifier with an amplification ratio of 1:1, so that the temperature comparison signal output by the temperature comparison circuit 20 can be buffered and isolated and then output to the control circuit 30 without changing the voltage value of the temperature comparison signal.

[0086] In one embodiment, the temperature fault detection circuit further includes:

[0087] A display, wherein the controlled end of the display is connected to the output end of the control circuit 30, and the control circuit 30 is also used to control the display to display the highest temperature value among the multiple target electronic devices when the temperature value corresponding to the temperature detection signal is less than a preset temperature value.

[0088] In this embodiment, the control circuit 30 can also compare the temperature comparison signal representing the target electronic device with the highest temperature value with a preset temperature threshold. The preset temperature threshold can be the highest temperature value at which the target electronic device can work normally. The temperature value of the specific preset temperature threshold can be set according to the specific model and type of the target electronic device, and factors such as the working environment of the target electronic device can also be considered. When the voltage value of the temperature comparison signal is less than or equal to the preset temperature threshold, it means that the target electronic device with the highest temperature value can work normally. At this time, no alarm is required, and the control circuit 30 can control the display to display the temperature value of the target electronic device. The display can be an LED display, and the staff can see the highest temperature value of the target electronic device through the display, which can also play a warning role. When it is found that the temperature value of the target electronic device is about to exceed the preset temperature threshold, the target electronic device is controlled to stop working or perform protection, reduce output power and other operations.

[0089] Reference Figures 2 to 5 In one embodiment, the temperature fault detection circuit further includes:

[0090] A connection fault detection circuit 40, wherein the input end of the connection fault detection circuit 40 is connected to the plurality of temperature sampling circuits 10, the output end of the connection fault detection circuit 40 is connected to the input end of the control circuit 30, and the connection fault detection circuit 40 is used to output a connection fault detection signal to the control circuit 30 according to the plurality of temperature sampling signals;

[0091] The control circuit 30 is used to determine whether any one of the plurality of target electronic devices has a connection fault according to the connection fault detection signal.

[0092] In this embodiment, the connection fault detection circuit 40 can determine whether there is a temperature sampling circuit 10 that is not connected to the target electronic device based on the temperature sampling signal. For example, if any target electronic device is not connected to the temperature sampling circuit 10, the connection fault detection circuit 40 can output a low-level electrical signal, that is, a fault detection signal to the control circuit 30, based on the temperature sampling signal output by the temperature sampling circuit 10 that is not connected to the target electronic device; if multiple target electronic devices and multiple temperature sampling circuits 10 are all connected normally, then at this time, the connection fault detection circuit 40 can output a high-level electrical signal, that is, a fault detection signal to the control circuit 30, based on the temperature sampling signal output by the temperature sampling circuit 10 that is connected to the target electronic device.

[0093] It can be understood that the control circuit 30 can first determine whether there is a temperature sampling circuit 10 that is not connected to the target electronic device based on the fault detection signal. If there is a temperature sampling circuit 10 that is not connected to the target electronic device, a fault signal is output to prompt the staff to check. If multiple temperature sampling circuits 10 are connected to multiple target electronic devices normally, it can be determined whether the temperature of the target electronic device is normal based on the temperature comparison signal output by the temperature comparison circuit 20, and an alarm signal is output when the temperature of the target electronic device is too high.

[0094] Reference Figure 3 In one embodiment, the connection fault detection circuit 40 includes a plurality of second comparators UA, each of which has a non-inverting input terminal, an inverting input terminal and an output terminal. The inverting input terminals of the plurality of second comparators UA are connected one-to-one with the output terminals of the plurality of temperature sampling circuits 10. The non-inverting input terminals of the plurality of second comparators UA are used to access a reference voltage Vref. The output terminals of the plurality of second comparators UA are connected to each other and to the input terminal of the control circuit 30.

[0095] In this embodiment, the connection fault detection circuit 40 can receive the temperature sampling signals output by the plurality of temperature sampling circuits 10 through the plurality of second comparators UA, and the reference voltage Vref connected to the non-phase input terminals of the plurality of second comparators UA can be set according to the characteristics of the second comparator UA and the sampling voltage value corresponding to the temperature range sampled by the temperature sampling circuit 10; it can be understood that when the voltage of the non-phase input terminal of the second comparator UA is higher than the voltage of the inverting input terminal, a high level is output, and when the voltage of the non-phase input terminal is lower than the voltage of the inverting input terminal, a low level is output; assuming that the preset temperature value in the above embodiment is 125 degrees, when the temperature of the target electronic device is lower than 125 degrees, it is in a normal connection state, then the voltage of the non-phase input terminal of the second comparator UA needs to be higher than the voltage output by the temperature sampling circuit 10 when the temperature of the target electronic device is 125 degrees, and lower than the voltage output by the temperature sampling circuit 10 when the target electronic device is not connected to the temperature sampling circuit 10, so as to avoid erroneous detection of a connection fault when the temperature of the target electronic device is normally detected. If all target electronic devices are connected to the temperature sampling circuit 10 normally, the output of the second comparator UA is high. If any target electronic device is not connected to the temperature sampling circuit 10 or has poor contact with the temperature sampling circuit 10, the voltage value corresponding to the temperature sampling signal corresponding to the target electronic device is higher than the preset voltage value. At this time, the second comparator UA outputs a low-level electrical signal to the control circuit 30. The control circuit 30 can determine that a target electronic device is not connected to the temperature sampling circuit 10 or has poor contact with the temperature sampling circuit 10 based on the low-level electrical signal. At this time, the output end of the connection fault detection circuit 40 and the output end of the temperature comparison circuit 20 are respectively connected to the two input ends of the control circuit 30, and the control circuit 30 can determine the temperature fault and connection fault of multiple target electronic devices based on the signals input from the two input ends.

[0096] Reference Figure 4In one embodiment, the connection fault detection circuit 40 further includes a plurality of second comparators UA, a third resistor R3, a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, a first switch tube Q1 and a second switch tube Q2, the second comparator UA having a non-inverting input terminal, a negative input terminal and an output terminal, the negative input terminals of the plurality of second comparators UA are connected one-to-one with the output terminals of the plurality of temperature sampling circuits 10, the positive input terminals of the plurality of second comparators UA are used to access a reference voltage Vref, the first terminal of the third resistor R3 is used to access a power supply voltage V, the second terminal of the third resistor R3, the The fourth resistor R4 and a first end are connected to the output ends of the plurality of second comparators UA, the second end of the fourth resistor R4, the first end of the fifth resistor R5 and the base of the first switch tube Q1 are connected to each other, the collector of the first switch tube Q1, the first end of the sixth resistor R6 and the gate of the second switch tube Q2 are connected to each other, the second end of the sixth resistor R6 is used to access the power supply voltage V, the drain of the second switch tube Q2 is connected to the output end of the temperature comparison circuit 20, and the second end of the fifth resistor R5, the emitter of the first switch tube Q1 and the source of the second switch tube Q2 are grounded.

[0097] In this embodiment, the connection fault detection circuit 40 can receive the temperature sampling signals output by the plurality of temperature sampling circuits 10 through the plurality of second comparators UA, and the reference voltage Vref connected to the non-phase input terminals of the plurality of second comparators UA can be set according to the characteristics of the second comparator UA and the sampling voltage value corresponding to the temperature range sampled by the temperature sampling circuit 10; it can be understood that when the voltage of the non-phase input terminal of the second comparator UA is higher than the voltage of the inverting input terminal, a high level is output, and when the voltage of the non-phase input terminal is lower than the voltage of the inverting input terminal, a low level is output; assuming that the preset temperature value in the above embodiment is 125 degrees, when the temperature of the target electronic device is lower than 125 degrees, it is in a normal connection state, then the voltage of the non-phase input terminal of the second comparator UA needs to be higher than the voltage output by the temperature sampling circuit 10 when the temperature of the target electronic device is 125 degrees, and lower than the voltage output by the temperature sampling circuit 10 when the target electronic device is not connected to the temperature sampling circuit 10, so as to avoid erroneous detection of a connection fault when the temperature of the target electronic device is normally detected. If all target electronic devices are connected to the temperature sampling circuit 10 normally, the output of the second comparator UA is high. If any target electronic device is not connected to the temperature sampling circuit 10 or has poor contact with the temperature sampling circuit 10, the voltage value corresponding to the temperature sampling signal corresponding to the target electronic device is higher than the preset voltage value. At this time, the second comparator UA outputs a low-level electrical signal to the control circuit 30. The control circuit 30 can determine that a target electronic device is not connected to the temperature sampling circuit 10 or has poor contact with the temperature sampling circuit 10 according to the low-level electrical signal. The output signal of the second comparator UA in the connection fault detection circuit 40 will not be directly output to the control circuit 30; if all the target electronic devices are connected to the temperature sampling circuit 10 normally, the comparator output is high impedance, and the power supply voltage V is output to the base of the first switch tube Q1 after being divided by the third resistor R3, the fourth resistor R4 and the fifth resistor R5. The base voltage of the first switch tube Q1 can be prevented from being too high by voltage division. After the base of the first switch tube Q1 receives a high level, the first switch tube Q1 is turned on, and the power supply voltage V is connected to the ground through the sixth resistor R6. At this time, the gate of the second switch tube Q2 is grounded, and the second switch tube Q2 is not turned on. The temperature ratio The temperature comparison signal output by the comparison circuit 20 can be normally output to the control circuit 30; if the thermistor of any target electronic device is not connected to the sampling circuit or is in poor contact with the sampling circuit, the second comparator UA outputs a low-level electrical signal, the power supply voltage V is pulled down through the third resistor R3, the first switch tube Q1 is not turned on, and the power supply voltage V is output to the gate of the second switch tube Q2 through the sixth resistor R6. The gate of the second switch tube Q2 receives a high level, and the second switch tube Q2 is turned on. At this time, the electrical signal output by the temperature comparison circuit 20, that is, the temperature comparison signal, will be pulled down to a low level, so that the control circuit 30 detects the low voltage and issues a temperature fault alarm.In this embodiment, the first switch tube Q1 can be a triode, and the second switch tube Q2 can be an NMOS tube. The specific type of switch tube can be selected according to the actual situation and user needs. In this embodiment, the output signal of the second comparator UA is processed and output to the control circuit 30, so that the control circuit 30 can alarm when any target electronic device is not connected to the temperature sampling circuit 10, and will not perform the function of judging whether the temperature value exceeds the preset temperature threshold. At this time, the output end of the fault detection circuit 40 and the output end of the temperature comparison circuit 20 are connected to an input end of the control circuit 30, so that the use of the input port of the control circuit 30 can be saved.

[0098] Reference Figures 3 to 5 In one embodiment, the temperature fault detection circuit further includes:

[0099] A first isolation circuit 50, wherein the first isolation circuit 50 is arranged in series between the temperature comparison circuit 20 and the control circuit 30; and / or,

[0100] A second isolation circuit 60, wherein the second isolation circuit 60 is arranged in series between the connection fault detection circuit 40 and the control circuit 30;

[0101] The first isolation circuit 50 is used to isolate and transform the temperature comparison signal output by the temperature comparison circuit 20 and then output it to the control circuit 30;

[0102] The second isolation circuit 60 is used to isolate and transform the fault detection signal output by the connection fault detection circuit 40 and then output it to the control circuit 30 .

[0103] In this embodiment, the first isolation circuit 50 and the second isolation circuit 60 can use an isolation operational amplifier or other devices with isolation function; the isolation operational amplifier is a special type of operational amplifier, which has the function of isolating input and output. The isolation operational amplifier can be used to electrically isolate two circuits to prevent signal interference and position difference. Therefore, by setting the first isolation circuit 50 and the second isolation circuit 60, the temperature comparison circuit 20 and the control circuit 30 and the connection fault detection circuit 40 and the control circuit 30 can be isolated to prevent signal interference, so that the control circuit 30 receives and processes the signal more accurately. It can be understood that the first isolation circuit 50 and the second isolation circuit 60 can be selected and set according to the design of the previous circuit; for example, the follower circuit in the above embodiment is set between the temperature comparison circuit 20 and the control circuit 30, and the follower circuit also has an isolation function, then the first isolation circuit 50 can be selected not to be set, thereby simplifying the circuit structure, or the first isolation circuit 50 can be set after the circuit to play a further isolation role. Alternatively, when the connection fault detection circuit 40 is composed of multiple second comparators UA, a third resistor R3, a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, a first switch tube Q1 and a second switch tube Q2, the output end of the connection fault detection circuit 40 is connected to the output end of the temperature comparison circuit 20, and there is no need to set up a second isolation circuit 60.

[0104] The invention also provides a temperature fault detection method.

[0105] In one embodiment, the temperature fault detection method comprises the following steps:

[0106] Collecting the temperatures of multiple target electronic devices and outputting corresponding multiple temperature sampling signals;

[0107] Comparing the plurality of temperature sampling signals, and outputting a temperature detection signal having the highest temperature value among the plurality of temperature sampling signals;

[0108] When the temperature value corresponding to the temperature detection signal is not less than a preset temperature value, it is determined that at least one of the plurality of target electronic components has a temperature fault.

[0109] In this embodiment, the temperature of multiple target electronic devices can be collected first, and multiple temperature sampling signals corresponding to the multiple target electronic devices can be obtained and output; the temperature sampling signal can be a voltage signal, and different voltage magnitudes correspond to different voltage values. By comparing the magnitudes of the voltage values ​​of multiple temperature sampling signals, a temperature detection signal with the highest temperature value among the multiple temperature sampling signals can be obtained; for example, the temperature sampling signal with the largest voltage value corresponds to the highest temperature value, or the temperature sampling signal with the smallest voltage value corresponds to the highest temperature value; the specific relationship between the voltage value magnitude and the temperature value can be determined according to the actual temperature detection device used. The sampling signal with the highest temperature value among the multiple temperature sampling signals is the temperature detection signal. When the temperature value represented by the temperature detection signal is not less than the preset temperature value, it indicates that the temperature of the target electronic device exceeds the maximum safe temperature value, which will affect the normal operation of the target electronic device or surrounding devices. At this time, it can be determined that at least one of the multiple target electronic devices has a temperature fault. The preset temperature value can be determined according to the model of the target electronic device and the actual application.

[0110] The present invention also provides a converter.

[0111] In one embodiment, the converter includes the temperature fault detection circuit as described above. The specific structure of the temperature fault detection circuit refers to the above embodiment. Since the converter adopts all the technical solutions of all the above embodiments, it at least has all the beneficial effects brought by the technical solutions of the above embodiments, which will not be described one by one here.

[0112] The above descriptions are only optional embodiments of the present invention, and are not intended to limit the patent scope of the present invention. All equivalent structural changes made using the contents of the present invention's specification and drawings under the technical concept of the present invention, or directly / indirectly applied in other related technical fields, are included in the patent protection scope of the present invention.

Claims

1. A temperature fault detection circuit, characterized in that: include: A plurality of temperature sampling circuits, wherein the plurality of temperature sampling circuits are used to correspondingly collect temperatures of a plurality of target electronic devices and output a plurality of corresponding temperature sampling signals; A temperature comparison circuit, used for comparing the multiple temperature sampling signals and outputting a temperature detection signal having the highest temperature value among the multiple temperature sampling signals; as well as The control circuit is used to determine that at least one of the multiple target electronic components has a temperature fault when the temperature value corresponding to the temperature detection signal with the highest temperature value is not less than a preset temperature value.

2. The temperature fault detection circuit according to claim 1, characterized in that: The temperature sampling circuit comprises a first resistor and a thermistor, wherein the first end of the first resistor is used to access the power supply voltage, the second end of the first resistor is connected to the first end of the thermistor and to the input end of the temperature comparison circuit, and the second end of the thermistor is grounded; The temperature comparison circuit includes a plurality of comparison units, the plurality of comparison units are connected one-to-one with a plurality of the temperature sampling circuits, and the output ends of the plurality of comparison units are connected to each other and serve as the output ends of the temperature comparison circuit.

3. The temperature fault detection circuit according to claim 2, characterized in that: The thermistor is a positive temperature coefficient thermistor.

4. The temperature fault detection circuit according to claim 2, characterized in that: The thermistor is a negative temperature coefficient thermistor; The temperature comparison circuit also includes a DC power supply terminal, and the output terminal of the multi-channel comparison unit is also connected to the DC power supply terminal and serves as the output terminal of the temperature comparison circuit.

5. The temperature fault detection circuit according to claim 2, characterized in that: The comparison unit includes a first comparator, which has a non-phase input terminal, an inverting input terminal and an output terminal. The non-phase input terminal of the first comparator is connected to the output terminal of the temperature sampling circuit, and the inverting input terminal of the first comparator is connected to the output terminal of the first comparator and serves as the output terminal of the comparison unit.

6. The temperature fault detection circuit according to any one of claims 2 to 4, characterized in that: The temperature comparison circuit also includes a single-phase output element, and the single-phase output element is connected between the output end of each comparison unit and the control circuit; the single-phase output element is used to isolate the output signals of the comparison units in other paths from flowing back to the comparison unit where the single-phase output element is located.

7. The temperature fault detection circuit according to claim 1, characterized in that: The temperature fault detection circuit also includes: A step-down circuit is provided in series between the temperature comparison circuit and the control circuit, and is used for stepping down the temperature comparison signal output by the temperature comparison circuit and outputting the result to the control circuit.

8. The temperature fault detection circuit according to claim 7, characterized in that: The step-down circuit includes a seventh resistor and an eighth resistor, the first end of the seventh resistor is connected to the output end of the temperature comparison circuit, the second end of the seventh resistor is connected to the first end of the eighth resistor and to the input end of the control circuit, and the second end of the eighth resistor is grounded.

9. The temperature fault detection circuit according to claim 1, characterized in that: The temperature fault detection circuit also includes: A follower circuit is provided in series between the temperature comparison circuit and the control circuit, and is used for isolating and impedance matching the temperature comparison signal output by the temperature comparison circuit and then outputting it to the control circuit.

10. The temperature fault detection circuit according to claim 9, characterized in that: The follower circuit includes a first operational amplifier, which has a non-phase input terminal, an inverting input terminal and an output terminal. The non-phase input terminal of the first operational amplifier is connected to the output terminal of the temperature comparison circuit, and the inverting input terminal of the first operational amplifier and the output terminal of the first operational amplifier are interconnected with the output terminal of the control circuit.

11. The temperature fault detection circuit according to claim 1, characterized in that: The temperature fault detection circuit also includes: A display, wherein a controlled end of the display is connected to an output end of the control circuit, and the control circuit is also used to control the display to display the highest temperature value among the multiple target electronic devices when the temperature value corresponding to the temperature detection signal is less than a preset temperature value.

12. The temperature fault detection circuit according to claim 1, characterized in that: The temperature fault detection circuit also includes: A connection fault detection circuit, wherein the input end of the connection fault detection circuit is connected to the plurality of temperature sampling circuits, the output end of the connection fault detection circuit is connected to the input end of the control circuit, and the connection fault detection circuit is used to output a connection fault detection signal to the control circuit when the voltage value corresponding to any temperature sampling signal is not less than a preset voltage value; The control circuit is further configured to determine, based on the connection fault detection signal, that a connection fault exists in at least one of the plurality of target electronic devices.

13. The temperature fault detection circuit according to claim 12, characterized in that: The connection fault detection circuit includes multiple second comparators, each of which has a non-phase input terminal, an inverting input terminal and an output terminal. The inverting input terminals of the multiple second comparators are connected one-to-one with the output terminals of the multiple temperature sampling circuits. The non-phase input terminals of the multiple second comparators are used to access a reference voltage. The output terminals of the multiple second comparators are connected to each other and to the input terminal of the control circuit.

14. The temperature fault detection circuit according to claim 12, characterized in that: The connection fault detection circuit also includes multiple second comparators, a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, a first switch tube and a second switch tube. The second comparator has a non-phase input terminal, an inverting input terminal and an output terminal. The inverting input terminals of the multiple second comparators are connected one-to-one with the output terminals of the multiple temperature sampling circuits. The non-phase input terminals of the multiple second comparators are used to access a reference voltage. The first end of the third resistor is used to access a power supply voltage. The second end of the third resistor, the first end of the fourth resistor and the output terminals of the multiple second comparators are connected to each other. The second end of the fourth resistor, the first end of the fifth resistor and the base of the first switch tube are connected to each other. The collector of the first switch tube, the first end of the sixth resistor and the gate of the second switch tube are connected to each other. The second end of the sixth resistor is used to access the power supply voltage. The drain of the second switch tube is connected to the output terminal of the temperature comparison circuit. The second end of the fifth resistor, the emitter of the first switch tube and the source of the second switch tube are grounded.

15. The temperature fault detection circuit according to claim 12, characterized in that: The temperature fault detection circuit also includes: A first isolation circuit, wherein the first isolation circuit is arranged in series between the temperature comparison circuit and the control circuit; and / or, a second isolation circuit, the second isolation circuit being arranged in series between the connection fault detection circuit and the control circuit; The first isolation circuit is used to isolate and transform the temperature comparison signal output by the temperature comparison circuit and then output it to the control circuit; The second isolation circuit is used to isolate and transform the fault detection signal output by the connection fault detection circuit and then output it to the control circuit.

16. A temperature fault detection method, characterized in that: The following steps are involved: Collecting the temperatures of multiple target electronic devices and outputting corresponding multiple temperature sampling signals; Comparing the plurality of temperature sampling signals, and outputting a temperature detection signal having the highest temperature value among the plurality of temperature sampling signals; When the temperature value corresponding to the temperature detection signal is not less than a preset temperature value, it is determined that at least one of the plurality of target electronic components has a temperature fault.

17. A converter, characterized in that: The method comprises the temperature fault detection circuit as described in any one of claims 1 to 15 or uses the temperature fault detection method as described in claim 16.

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