TWI764745B - Temperature detection device - Google Patents

Abstract

A temperature detection device is disclosed. The temperature detection device comprises a plurality of thermistors, a voltage source and a plurality of temperature detection circuits. A first terminal of each of thermistors is electrically connected to a common node. The voltage source is directly and electrically connected to the common node. The plurality of temperature detection circuits are electrically connected to the common node and a second terminal of the corresponding thermistor, respectively. Each of temperature detection circuits comprises a voltage divider circuit and a differential amplifier circuit. The voltage divider circuit comprises a first resistor and a second resistor, wherein a first terminal of the first resistor is electrically connected to the common node, a second terminal of the first resistor is electrically connected to a first terminal of the second resistor and the second terminal of the corresponding thermistor, and a second terminal of the second resistor is electrically connected to a ground. The differential amplifier circuit comprises a first input terminal, a second input terminal and an output terminal, wherein the first input terminal is electrically connected to the first terminal of the first resistor and the common node, and the second terminal is electrically connected to the second terminal of the first resistor.

Description

temperature detection device

This case relates to a temperature detection device, especially a temperature detection device that can reduce the noise effect caused by common mode noise and avoid the mutual influence of multiple temperature detection circuits depending on the loop.

In various electronic devices, a temperature detection device is generally installed, so that the electronic device has an over-temperature protection function. Taking the field of electric vehicles as an example, for electric vehicles, the charging gun and the charging gun holder are used as the medium between the charging equipment and the electric vehicle. The design specification of the gun and the charging gun holder establishes the safety specification. Among them, in order to ensure the working temperature of the charging gun and the charging gun holder, the industry will add a thermistor (Thermistor) to the charging gun holder, and cooperate with the temperature detection circuit to monitor the temperature status in real time, and the accurate temperature value report and self-diagnosis The function of error has become an important indicator of security.

Furthermore, in order to achieve multi-position detection or reliability, a plurality of thermistors with electrical connections are generally used in conjunction with a plurality of temperature detection circuits to monitor the temperature state in real time. Please refer to FIG. 1 , which is a schematic diagram of a circuit structure when a plurality of conventional thermistors are electrically connected. As shown in Figure 1, when a plurality of thermistors Rth are connected in series, in parallel, or any combination of the two, with a common node Ncom being connected (Figure 1 illustrates a plurality of thermistors The resistors Rth are connected in parallel), thereby realizing the temperature detection function of the respective thermistors Rth.

However, no matter what kind of connection method with a common contact is used for a plurality of thermistors, there are some problems when they perform respective temperature detections and cooperate with the corresponding temperature detection circuits. First of all, the first problem is that the leads are prone to common mode noise (Common Mode Noise), which affects the accuracy of the temperature return value. The second problem is that the common contact that is currently electrically connected to a plurality of thermistors is also connected to the power supply through a pull-up resistor. With the settings of the pull-up resistor and power supply, the temperature detection circuit can detect the thermistor. Whether it is empty connection or whether the two terminals of the thermistor are short-circuited to the ground, but also because of the setting of the pull-up resistor, the voltage of the common contact Ncom will change with the impedance of each loop, resulting in multiple temperature detection. The circuits form an interdependent loop and influence each other, and it is difficult to realize the function of normal temperature judgment and self-diagnosis error of each thermistor setting position.

Therefore, how to develop a temperature detection device to solve the problems faced by the prior art is a problem that needs to be faced in the art.

This case is a temperature detection device to solve the problem that when the traditional temperature detection device uses a plurality of thermistors for individual temperature detection, the lead connection method is prone to generate common mode noise, resulting in poor accuracy of the temperature report value. And because the thermistor will form a dependent loop and affect each other, it is difficult to achieve correct temperature readings and self-diagnosis errors and other functions.

In order to achieve the aforementioned purpose, this case provides a temperature detection device: a plurality of thermistors, respectively including a first end and a second end, the plurality of first ends of the plurality of thermistors are electrically connected to each other at a common contact; voltage The source is directly electrically connected to the common contact and provides a stable voltage; and a plurality of temperature detection circuits, each temperature detection circuit is electrically connected to a corresponding thermistor, and each temperature detection circuit includes: a voltage divider The circuit includes a first resistor and a second resistor. The first end of the first resistor is electrically connected to the common contact, and the second end of the first resistor is electrically connected to the first end of the second resistor and the first end of the corresponding thermistor. two terminals, the second terminal of the second resistor is electrically connected to the ground terminal; and the differential amplifier circuit includes a first input terminal, a second input terminal and an output terminal, the first input terminal is electrically connected to the first terminal of the first resistor and the Common contacts, the second input terminal is electrically connected to the second terminal of the first resistor and the second terminal of the corresponding thermistor, the output terminal outputs a temperature detection signal, and the temperature detection signal reflects the resistance value of the corresponding thermistor Variety.

Some typical embodiments embodying the features and advantages of the present case will be described in detail in the description of the latter paragraph. It should be understood that this case can have various changes in different aspects, all of which do not depart from the scope of this case, and the descriptions and drawings therein are essentially used for illustration rather than for limiting this case.

The electrical connection described in the following specification, unless otherwise specified, can generally refer to the state in which electrical signals can be transmitted between two ends, such as direct electrical connection between the two ends, indirect electrical connection between the two ends through other conductors Electrical connection or the same potential between the two ends.

Please refer to FIG. 2 , which is a schematic diagram of the circuit structure of the temperature detection device according to the preferred embodiment of the present invention. As shown in the figure, the temperature detection device 1 of this embodiment can be applied to an electric vehicle, and the following will also be an exemplary description of the temperature detection device 1 applied to an electric vehicle, but it is not limited to this, and there are a plurality of The temperature detection device 1 of the present application can be applied to electronic devices with temperature detection requirements at different internal locations.

The temperature detection device 1 includes a voltage source 10 , a plurality of thermistors Rth, and a plurality of temperature detection circuits 11 , wherein each thermistor Rth has a corresponding temperature detection circuit 11 . The detection device 1 includes two thermistors Rth and two temperature detection circuits 11 for exemplary illustration. However, the number of the thermistors Rth and the temperature detection circuits 11 may be three or more respectively.

Each thermistor Rth can be disposed at different positions in the electric gun seat, for example, to change the resistance value according to the temperature change of the position, and each thermistor Rth has a first end and a second end respectively. terminals, wherein the first terminals of the plurality of thermistors Rth are electrically connected to each other at the common contact Ncom.

The voltage source 10 is directly electrically connected to the common contact Ncom (the word direct here is defined as no other electronic components exist between the voltage source 10 and the common contact Ncom), and provides a stable voltage. Each temperature detection circuit 11 is electrically connected to the first end and the second end of the corresponding thermistor Rth, and each temperature detection circuit 11 is structured to detect the resistance change of the corresponding thermistor Rth, thereby providing The temperature detection signal Vo reflecting the temperature information at the position of the corresponding thermistor Rth, wherein each temperature detection circuit 11 includes a voltage divider circuit 110 and a differential amplifier 111 . The voltage divider circuit 110 includes a first resistor R1 and a second resistor R2, the first end of the first resistor R1 is electrically connected to the common node Ncom, the second end of the first resistor R1, the first end of the second resistor R2 and The second end of the corresponding thermistor Rth is commonly connected to the detection terminal A, and the second end of the second resistor R2 is electrically connected to the ground terminal G.

The differential amplifier circuit 111 includes a first input terminal, a second input terminal and an output terminal. The first input terminal of the differential amplifier circuit 111 is electrically connected to the first terminal of the first resistor R1 and the common contact Ncom. The differential amplifier circuit The second input terminal of 111 is electrically connected to the second terminal of the first resistor R1 and the second terminal of the corresponding thermistor Rth, namely, is electrically connected to the detection terminal A, and the output terminal of the differential amplifier circuit 111 outputs the temperature Detection signal Vo. The temperature detection circuit 11 detects the resistance change of the corresponding thermistor Rth through the differential amplifier circuit 111, and then provides a temperature detection signal Vo reflecting the temperature information of the position of the corresponding thermistor Rth.

In addition, in this embodiment, each temperature detection circuit 11 can detect whether the corresponding thermistor Rth is disconnected or whether the terminal of the thermistor Rth is short-circuited to ground by the setting of the voltage divider circuit 110 . To further illustrate, when the thermistor Rth is normally connected, the voltage on the detection terminal A in the corresponding temperature detection circuit 11 is equivalent to the thermistor Rth being connected in parallel with the first resistor R1 and forming a voltage divider with the second resistor R2. . When any thermistor Rth is left open, the voltage on the detection terminal A in the corresponding temperature detection circuit 11 is divided by the voltage of the voltage source 10 and the first resistor R1 and the second resistor R2. Determined, the voltage between the common contact Ncom and the detection terminal A is maintained at the first voltage level; and when the second terminal of any thermistor Rth is short-circuited to the ground, the corresponding temperature detection circuit The voltage on the detection terminal A in 11 is equivalent to a short circuit to the ground, and the voltage between the common contact Ncom and the detection terminal A is maintained at the second voltage level; if the first voltage of any thermistor Rth When the terminal is shorted to ground, the voltage between the common contact Ncom and the detection terminal A is zero, wherein the first voltage level is different from the second voltage level. Therefore, according to whether the voltage between the common contact Ncom and the detection terminal A is the first voltage level, the second voltage level or zero, it can be detected whether the thermistor Rth is empty or whether the two terminals of the thermistor Rth are connected. Is the point shorted to ground. In other words, the temperature detection signal Vo output by the temperature detection circuit 11 can be used to detect and determine whether the thermistor Rth is disconnected or whether one terminal of the thermistor Rth is short-circuited to ground.

Since the temperature detection device 1 of this application includes a plurality of thermistors Rth and a plurality of corresponding temperature detection circuits 11 , and the setting positions of the plurality of thermistors Rth are different, the detection of each temperature detection circuit 11 The result reflects the temperature information at the location of the corresponding thermistor Rth. As a result, the temperature detection device 1 of the present application can be applied to electronic devices with temperature detection requirements of different internal locations. In addition, since each temperature detection circuit 11 of the temperature detection device 1 of this application includes a differential amplifier circuit 111 , the common mode noise can be reduced by the characteristics of the differential amplifier circuit 111 , so that the temperature detection of this application can be achieved. The accuracy of the temperature report of device 1 has been improved. What's more, since the temperature detection device 1 of this application includes a voltage source 10 that is directly electrically connected to the common node Ncom, and each temperature detection circuit 11 has a voltage divider circuit 110, the temperature detection circuit 11 can be The cooperation of the voltage source 10 and the voltage divider circuit 11 is used to detect whether the thermistor Rth is disconnected or whether the two terminals of the thermistor Rth are short-circuited to the ground, so the temperature detection device 1 in this case does not need to be as conventional The temperature detection circuit needs to be provided with a pull-up resistor that is electrically connected to the common contact Ncom, which can avoid the effect of equivalent voltage division. In this way, the plurality of temperature detection circuits 11 in this case will not form a dependent loop and affect each other. , so that the temperature detection device 1 can realize the functions of normal temperature reading and self-diagnosing errors.

In some embodiments, as shown in FIG. 2, each differential amplifier circuit 111 includes a first amplifier 112, the first amplifier 112 may be an operational amplifier, and the non-inverting input terminal of the first amplifier 112 is coupled to the differential amplifier 112. The first input terminal of the differential amplifier circuit 111 and the inverting input terminal of the first amplifier 112 are coupled to the second input terminal of the differential amplifier circuit 111 , and the output terminal of the first amplifier 112 constitutes the output terminal of the differential amplifier circuit 111 .

Please refer to FIG. 3 , which is a schematic diagram of a detailed circuit structure of the temperature detection device shown in FIG. 2 . As shown in FIG. 3 , in this embodiment, the voltage source 10 includes a second amplifier 100 , a third resistor R3 and a blocking circuit 101 . The blocking circuit 101 is electrically connected to the common node Ncom to prevent the current from flowing back to the voltage source 10 from the common contact Ncom. In some embodiments, the second amplifier 100 is an operational amplifier, and the blocking circuit 101 may include a first In the diode D1, the cathode terminal of the first diode D1 is electrically connected to the common contact Ncom. Of course, in other embodiments, the blocking circuit 101 may also include other electronic components that can limit the current flow path, such as switching components such as bipolar transistors. The first terminal of the third resistor R3 is electrically connected to the output terminal of the second amplifier 100 , the second terminal of the third resistor R3 is electrically connected to the anode terminal of the first diode D1 of the blocking circuit 10 , and the third resistor R3 is constructed in Provides the function of current limiting. In another embodiment, the third resistor R3 and the first diode D1 can be replaced with each other to maintain the current limiting and blocking functions. The non-inverting input terminal of the second amplifier 100 receives the first reference voltage Vref1 , the inverting input terminal of the second amplifier 100 is electrically connected to the cathode terminal of the first diode D1 of the blocking circuit 10 , and the second amplifier 100 The connection relationship shows that the second amplifier 100 has a negative feedback circuit structure, so that the first diode D1 cooperates with the second amplifier 100 to form a super diode, so the voltage source 10 can output a stable voltage to the common node Ncom. Of course, the circuit structure of the voltage source 10 is not limited to the above, and any circuit structure that can provide a stable voltage can constitute the voltage source 10 . The blocking circuit 101 can also be an NPN type bipolar transistor, the base of which is connected to the second terminal of the third resistor R3, and the emitter is connected to the reverse input terminal of the second amplifier 100, so that the common contact Ncom can be kept stable. the first reference voltage Vref1, and also has the function of blocking the flow of current to the first reference voltage Vref1.

In addition, in some embodiments, each differential amplifier circuit 111 includes a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, an eighth resistor R8 and a ninth resistor R9. The first end of the fourth resistor R4 is electrically connected to the common contact Ncom. The first terminal of the sixth resistor R6 is electrically connected to the second terminal of the fourth resistor R4 , and the second terminal of the sixth resistor R6 is electrically connected to the non-inverting input terminal of the first amplifier 112 . The first terminal of the eighth resistor R8 is electrically connected to the second terminal of the sixth resistor R6 and the non-inverting input terminal of the first amplifier 112 , and the second terminal of the eighth resistor R8 is electrically connected to the ground terminal G. The first end of the fifth resistor R5 is electrically connected to the second end of the corresponding thermistor Rth. The first end of the seventh resistor R7 is electrically connected to the second end of the fifth resistor R5. The first end of the ninth resistor R9 is electrically connected to the second end of the seventh resistor R7 , and the second end of the ninth resistor R9 is electrically connected to the output end of the first amplifier 112 . Through the setting of the third resistor R3, the fourth resistor R4, the fifth resistor R5, the sixth resistor R6, the seventh resistor R7, the eighth resistor R8 and the ninth resistor R9, the differential amplifier circuit 111 can realize the differential Mode amplification function, and then more effectively reduce common mode noise.

In other embodiments, each differential amplifier circuit 111 further includes a first capacitor C1, a second capacitor C2, a third capacitor C3 and a fourth capacitor C4. The first terminal of the first capacitor C1 is electrically connected to the second terminal of the fourth resistor R4 and the first terminal of the sixth resistor R6 , and the second terminal of the first capacitor C1 is electrically connected to the ground terminal G. The first terminal of the second capacitor C2 is electrically connected to the second terminal of the first capacitor C1 and the ground terminal G, and the second terminal of the second capacitor C2 is electrically connected to the second terminal of the fifth resistor R5 and the first terminal of the seventh resistor R7 one end. The first end of the third capacitor C3 is electrically connected to the second end of the fourth resistor R4 and the first end of the sixth resistor R6, and the second end of the third capacitor C3 is electrically connected to the second end of the fifth resistor R5 and the first end of the sixth resistor R6. The first terminal of seven resistor R7. The first end of the fourth capacitor C4 is electrically connected to the second end of the sixth resistor R6 and the non-inverting input end of the first amplifier 112, and the second end of the fourth capacitor C4 is electrically connected to the second end of the seventh resistor R7 , the first terminal of the ninth resistor R9 and the inverting input terminal of the first amplifier 112 . The first capacitor C1 to the fourth capacitor C4 are configured to provide a filtering function.

In addition, each differential amplifier circuit 111 further includes a second diode D2 and a third diode D3, wherein the cathode terminal of the second diode D2 receives the second reference voltage Vref2, and the anode terminal of the second diode D2 receives the second reference voltage Vref2. The terminal is electrically connected to the second end of the fourth resistor R4 and the first end of the sixth resistor R6. The cathode terminal of the third diode D3 receives the second reference voltage Vref2, and the anode terminal of the third diode D3 is electrically connected to the second terminal of the fifth resistor R5 and the first terminal of the seventh resistor R7. The second diode D2 and the third diode D4 are structured to provide a voltage clamping function.

Each differential amplifier circuit 111 further includes a fifth capacitor C5 and a sixth capacitor C6. The first terminal of the fifth capacitor C5 is electrically connected to the second terminal of the sixth resistor R6 and the non-inverting input terminal of the first amplifier 112 , and the second terminal of the fifth capacitor C5 is electrically connected to the ground terminal G. The first end of the sixth capacitor C6 is electrically connected to the second end of the seventh resistor R7, the first end of the ninth resistor R9 and the reverse input end of the first amplifier 112, and the second end of the sixth capacitor C6 is electrically connected to the Ground terminal G. By setting the fifth capacitor C5 and the sixth capacitor C6, the differential amplifier circuit 111 can be configured as a low-pass filtering differential amplifier circuit.

Please refer to Fig. 4 in conjunction with Fig. 2 and Fig. 3, wherein Fig. 4 is a schematic diagram of the simulation results of the temperature detection device of the present application under different temperatures. In Figure 4, four simulation situations are simulated under the condition of multiple thermistors Rth being disconnected, at the temperature of -40°C, at the temperature of 25°C, and at the temperature of 150°C. , the curve A represents the temperature detection signal outputted by the temperature detection circuit under four simulation conditions when the temperature detection device uses a single temperature detection circuit to detect a thermistor, and the curve B and the curve C are The temperature detection signals output by the two temperature detection circuits 11 of the temperature detection device 1 of the present case shown in FIG. 2 respectively change under four simulation conditions, wherein it is assumed that the temperature detection circuit corresponding to the curve A The detected thermistor and the thermistor group Rth detected by the temperature detection circuit 11 corresponding to the curve B are the same thermistor group and are arranged in the same position. As shown in FIG. 4, when the two temperature detection circuits 11 of the temperature detection device 1 of the present case are performing temperature detection, in any simulation state, one of the temperature detection circuits 11 of the temperature detection device 1 The variation of the temperature detection signal represented by the corresponding curve B is the same as the variation of the temperature detection signal represented by the curve A, and will not be affected by another temperature detection circuit 11 (ie, curve C) of the temperature detection device 1 . Therefore, it can be proved that since the temperature detection device 1 of the present application includes a voltage source 10 that is directly electrically connected to the common contact Ncom, and the common contact Ncom is not electrically connected to any pull-up resistor, a plurality of temperature detection circuits 11 They do not form a dependent loop and influence each other.

In summary, the present application provides a temperature detection device, wherein the temperature detection device includes a plurality of thermistors and a plurality of temperature detection circuits, whereby the temperature detection device of the present application can be used to detect different positions in an electronic device temperature. In addition, each temperature detection circuit of the temperature detection device of the present application can reduce the common mode noise by the characteristics of the differential amplifier circuit, so that the accuracy of the temperature report of the temperature detection device of the present application is improved. What's more, since the temperature detection device in this case includes a voltage source directly electrically connected to the common contact, and each temperature detection circuit has a voltage divider circuit, the temperature detection circuit can be divided by the voltage source and the voltage divider circuit. The matching of the circuit can detect whether the thermistor is empty or whether the two terminals of the thermistor are short-circuited to the ground, so there is no need to set any pull-up resistor to electrically connect with the common contact, so the multiple temperature detection circuits are not connected to the ground. It will not form an interdependent loop and influence each other, so that the temperature detection device of this case can realize the functions of correct temperature reading and self-diagnosis error.

This case can be modified by a person who is familiar with this technology, and all kinds of modifications can be made without departing from the protection of the scope of the patent application attached.

Rth: thermistor Ncom: common contact 1: Temperature detection device 10: Voltage source 11: Temperature detection circuit 110: Voltage divider circuit 111: Difference amplifier circuit R1: first resistor R2: Second resistor A: Detection endpoint G: ground terminal 112: First Amplifier Vo: temperature detection signal 100: Second amplifier R3: the third resistor 101: Blocking Circuits D1: first diode Vref1: The first reference voltage R4: Fourth resistor R5: Fifth resistor R6: sixth resistor R7: seventh resistor R8: Eighth resistor R9: ninth resistor C1: first capacitor C2: second capacitor C3: the third capacitor C4: Fourth capacitor D2: Second diode D3: Third diode Vref2: The second reference voltage C5: Fifth capacitor C6: sixth capacitor A, B, C: Curves

Figure 1 is a schematic diagram of the circuit structure when a plurality of traditional thermistors are electrically connected; FIG. 2 is a schematic diagram of the circuit structure of the temperature detection device according to the preferred embodiment of the present invention; Figure 3 is a schematic diagram of a detailed circuit structure of the temperature detection device shown in Figure 2; FIG. 4 is a schematic diagram of the simulation results of the temperature detection device of the present case simulating at different temperatures.

Rth: thermistor

Ncom: common contact

1: Temperature detection device

10: Voltage source

11: Temperature detection circuit

110: Voltage divider circuit

111: Difference amplifier circuit

R1: first resistor

R2: Second resistor

G: ground terminal

112: First Amplifier

A: Detection endpoint

Vo: temperature detection signal

Claims (10)

A temperature detection device: a plurality of thermistors, respectively including a first end and a second end, the plurality of the first ends of the plurality of thermistors are electrically connected to each other in a common contact; a voltage source, directly electrically connected to the common contact, and providing a stable voltage; and A plurality of temperature detection circuits, each of the temperature detection circuits is electrically connected to the corresponding thermistor, and each of the temperature detection circuits includes: A voltage divider circuit includes a first resistor and a second resistor, a first end of the first resistor is electrically connected to the common contact, and a second end of the first resistor is electrically connected to the second resistor A first end of the corresponding thermistor and the second end of the thermistor, a second end of the second resistor is electrically connected to a ground end; and A differential amplifier circuit includes a first input end, a second input end and an output end, the first input end is electrically connected to the first end of the first resistor and the common contact, the second input end The terminal is electrically connected to the second terminal of the first resistor and the second terminal of the corresponding thermistor, the output terminal outputs a temperature detection signal, and the temperature detection signal reflects the resistance of the corresponding thermistor value changes. The temperature detection device of claim 1, wherein the differential amplifier circuit comprises a first amplifier, a non-inverting input terminal of the first amplifier is coupled to the first input terminal, and an inverting terminal of the first amplifier is coupled to the first input terminal. The second input end is coupled to the input end, and an output end of the first amplifier constitutes the output end of the differential amplifier circuit. The temperature detection device of claim 1, wherein the voltage source comprises: a blocking circuit, electrically connected to the common contact, configured to prevent the current on the common contact from flowing back to the voltage source; a second amplifier, a non-inverting input terminal of the second amplifier receives a first reference voltage, and an inverting input terminal of the first amplifier is electrically connected to the blocking circuit; and A third resistor, a first end of the third resistor is electrically connected to an output end of the second amplifier, and a second end of the third resistor is electrically connected to the blocking circuit. The temperature detection device of claim 3, wherein the blocking circuit comprises a first diode, a cathode terminal of the first diode is electrically connected to the common contact, and an anode of the first diode is electrically connected to the common contact. The terminal is electrically connected to the second end of the third resistor. The temperature detection device as claimed in claim 3, wherein the blocking circuit comprises an NPN type bipolar transistor, a base of the NPN type bipolar transistor is connected to the second end of the third resistor, the NPN type bipolar transistor An emitter of the bipolar transistor is connected to the inverting input of the second amplifier. The temperature detection device of claim 2, wherein the differential amplifier circuit comprises a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor and a ninth resistor, the A first end of the fourth resistor is electrically connected to the common contact, a first end of the sixth resistor is electrically connected to a second end of the fourth resistor, and a second end of the sixth resistor is electrically connected to The non-inverting input end of the first amplifier, a first end of the eighth resistor is electrically connected to the second end of the sixth resistor and the non-inverting input end of the first amplifier, the eighth resistor The second terminal is electrically connected to the ground terminal, a first terminal of the fifth resistor is electrically connected to the corresponding second terminal of the thermistor, and a first terminal of the seventh resistor is electrically connected to the fifth resistor A second end of the ninth resistor is electrically connected to a second end of the seventh resistor, and a second end of the ninth resistor is electrically connected to the output end of the first amplifier. The temperature detection device according to claim 6, wherein the differential amplifier circuit further comprises a first capacitor, a second capacitor, a third capacitor and a fourth capacitor, and a first terminal of the first capacitor is electrically connected to connected to the second terminal of the fourth resistor and the first terminal of the sixth resistor, a second terminal of the first capacitor is electrically connected to the ground terminal, and a first terminal of the second capacitor is electrically connected to The second end of the first capacitor and the ground end, a second end of the second capacitor is electrically connected to the second end of the fifth resistor and the first end of the seventh resistor, the third capacitor A first end of the third capacitor is electrically connected to the second end of the fourth resistor and the first end of the sixth resistor, and a second end of the third capacitor is electrically connected to the second end of the fifth resistor and the The first end of the seventh resistor, a first end of the fourth capacitor are electrically connected to the second end of the sixth resistor and the non-inverting input end of the first amplifier, and a second end of the fourth capacitor It is electrically connected to the second end of the seventh resistor, the first end of the ninth resistor and the reverse input end of the first amplifier. The temperature detection device of claim 6, wherein the differential amplifier circuit further comprises a second diode and a third diode, wherein a cathode terminal of the second diode receives a second reference voltage, an anode terminal of the second diode is electrically connected to the second terminal of the fourth resistor and the first terminal of the sixth resistor, and a cathode terminal of the third diode receives the second reference voltage , an anode end of the third diode is electrically connected to the second end of the fifth resistor and the first end of the seventh resistor. The temperature detection device of claim 6, wherein the differential amplifier circuit further comprises a fifth capacitor and a sixth capacitor, a first end of the fifth capacitor is electrically connected to the second end of the sixth resistor terminal and the non-inverting input terminal of the first amplifier, a second terminal of the fifth capacitor is electrically connected to the ground terminal, and a first terminal of the sixth capacitor is electrically connected to the second terminal of the seventh resistor , the first terminal of the ninth resistor and the reverse input terminal of the first amplifier, and a second terminal of the sixth capacitor is electrically connected to the ground terminal. The temperature detection device of claim 1, wherein the second end of the first resistor and the first end of the second resistor of each temperature detection circuit are electrically connected to the corresponding temperature detection circuit A detection terminal in the temperature detection circuit, and when any of the thermistors is disconnected, the voltage between the common contact and the detection terminal in the corresponding temperature detection circuit is maintained at a first voltage level When the second terminal of any of the thermistors is short-circuited to ground, the voltage between the common contact and the detection terminal in the corresponding temperature detection circuit is maintained at a second voltage level bit, wherein the first voltage level is different from the second voltage level.

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