Temperature detection circuit and industrial device

Abstract

The utility model provides a kind of temperature detection circuit and industrial equipment, the temperature detection circuit includes temperature detection device, adjustable bridge circuit, amplifier circuit and proportion adjustment circuit;The adjustable bridge circuit is connected with the temperature detection device, and one end of the adjustable bridge circuit is connected with the control circuit of the industrial equipment;One end of the amplifier circuit is connected with the other end of the adjustable bridge circuit, and the other end of the amplifier circuit is connected with the control circuit;One end of the proportion adjustment circuit is connected with the amplifier circuit, and the other end of the proportion adjustment circuit is connected with the control circuit.The utility model not only can be compatible with multiple types of temperature detection device, but also can reduce replacement cost, improve convenience.

Description

Technical Field

[0001] This utility model relates to the field of temperature detection technology, specifically to a temperature detection circuit and industrial equipment. Background Technology

[0002] Industrial equipment typically requires temperature detection devices to collect temperature data. There are various types of temperature detection devices. Generally, one type of temperature detection device corresponds to one temperature detection circuit. When replacing a temperature detection device, the temperature detection circuit must also be replaced or its parameters modified, resulting in high replacement costs and poor convenience. Utility Model Content

[0003] This invention provides a temperature detection circuit and industrial equipment, aiming to solve the problem that current temperature detection circuits can only be matched with one type of temperature detection device.

[0004] In a first aspect, this utility model provides a temperature detection circuit for use in industrial equipment. The temperature detection circuit includes a temperature detection device, an adjustable bridge circuit, an amplifier circuit, and a proportional adjustment circuit. The adjustable bridge circuit is connected to the temperature detection device, and one end of the adjustable bridge circuit is connected to the control circuit of the industrial equipment. One end of the amplifier circuit is connected to the other end of the adjustable bridge circuit, and the other end of the amplifier circuit is connected to the control circuit. One end of the proportional adjustment circuit is connected to the amplifier circuit, and the other end of the proportional adjustment circuit is connected to the control circuit.

[0005] Furthermore, the adjustable bridge circuit includes a first switching circuit and a bridge circuit; one end of the first switching circuit is connected to the control circuit, the other end of the first switching circuit is connected to the bridge circuit, and the bridge circuit is connected to the temperature detection device and the amplification circuit respectively.

[0006] Furthermore, the first switching circuit includes a first switching transistor, the controlled terminal of the first switching transistor is connected to the control circuit, the first terminal of the first switching transistor is grounded, and the second terminal of the first switching transistor is connected to the bridge circuit.

[0007] Furthermore, the bridge circuit includes a first resistor, a second resistor, a third resistor, and a fourth resistor; one end of the first resistor and one end of the second resistor are both connected to the power supply terminal, the other end of the first resistor is connected to one end of the third resistor, one end of the fourth resistor, and the amplifier circuit, the other end of the second resistor is connected to the temperature detection device, the other end of the third resistor is connected to the second terminal of the first switching transistor, and the other end of the fourth resistor is grounded.

[0008] Furthermore, the proportional adjustment circuit includes a second switching circuit and a voltage divider circuit; one end of the voltage divider circuit is connected to the bridge circuit through the amplifier circuit, the other end of the voltage divider circuit is connected to the amplifier circuit, and the voltage divider circuit is also connected to the second switching circuit, which is connected to the control circuit.

[0009] Furthermore, the second switching circuit includes a second switching transistor, the controlled terminal of the second switching transistor is connected to the control circuit, the first terminal of the second switching transistor is grounded, and the second terminal of the second switching transistor is connected to the voltage divider circuit.

[0010] Furthermore, the amplification circuit includes a differential amplification circuit, a proportional amplification circuit, and a filter circuit; one end of the differential amplification circuit is connected to the bridge circuit, the other end of the differential amplification circuit is connected to one end of the proportional amplification circuit through the voltage divider circuit, the other end of the proportional amplification circuit is connected to one end of the filter circuit, and the other end of the filter circuit is connected to the control circuit.

[0011] Furthermore, the differential amplifier circuit includes a first operational amplifier, the non-inverting input terminal and the inverting input terminal of the first operational amplifier are respectively connected to different arms of the bridge circuit, and the output terminal of the first operational amplifier is connected to the proportional amplifier circuit through the voltage divider circuit.

[0012] Furthermore, the proportional amplifier circuit includes a second operational amplifier, the non-inverting input terminal of the second operational amplifier is connected to the differential amplifier circuit through the voltage divider circuit, the inverting input terminal of the second operational amplifier is connected to the output terminal of the second operational amplifier, and the output terminal of the second operational amplifier is connected to the filter circuit.

[0013] Secondly, this utility model also provides an industrial device, which includes a control circuit and the temperature detection circuit described in any of the above claims.

[0014] The industrial equipment disclosed in this utility model includes a control circuit and a temperature detection circuit. The temperature detection circuit includes a temperature detection device, an adjustable bridge circuit, an amplifier circuit, and a proportional adjustment circuit. The adjustable bridge circuit is connected to the temperature detection device, the amplifier circuit, and the control circuit respectively, and can be turned on and off under the control of the control circuit to change its resistance value. The proportional adjustment circuit is connected to the amplifier circuit and the control circuit respectively, and can be turned on and off under the control of the control circuit to change the resistance value of the amplifier circuit. The amplifier circuit can send the temperature signal from the temperature detection device to the control circuit to realize temperature detection. By changing the conduction state of the adjustable bridge circuit and the proportional adjustment circuit, it can adapt to at least two types of temperature detection devices, and thus be compatible with multiple types of temperature detection devices. This not only reduces replacement costs but also improves convenience. Attached Figure Description

[0015] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a block diagram of a temperature detection circuit provided in an embodiment of the present invention; Figure 2 This is a block diagram of a temperature detection circuit provided in another embodiment of the present invention; Figure 3 This is a circuit diagram of a temperature detection circuit provided in one embodiment of the present invention. Detailed Implementation

[0017] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present utility model.

[0018] It should be understood that, when used in this specification and the appended claims, the terms “comprising” and “including” indicate the presence of the described features, integrals, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integrals, operations, elements, components and / or collections thereof.

[0019] It should also be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the scope of the invention. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used in this specification and the appended claims refers to any combination and all possible combinations of one or more of the associated listed items, and includes such combinations.

[0020] Furthermore, the directional terms used in this invention, such as "up," "down," "front," "back," "left," "right," "inner," "outer," and "side," are only for reference to the accompanying drawings and the product's usage state. Therefore, the directional terms used are for explaining and understanding this invention, and not for limiting it. Additionally, in the accompanying drawings, structures that are similar or identical are indicated by the same reference numerals.

[0021] See Figures 1 to 3 , Figure 1 This is a block diagram of a temperature detection circuit 100 provided in an embodiment of the present invention; Figure 2 This is a block diagram of a temperature detection circuit 100 provided in another embodiment of the present invention; Figure 3 This is a circuit diagram of a temperature detection circuit 100 provided in one embodiment of this utility model. Figure 1 As shown, the temperature detection circuit 100 includes a temperature detection device 10, an adjustable bridge circuit 20, an amplifier circuit 30, and a proportional adjustment circuit 40; the adjustable bridge circuit 20 is connected to the temperature detection device 10, and one end of the adjustable bridge circuit 20 is connected to the control circuit 200 of the industrial equipment; one end of the amplifier circuit 30 is connected to the other end of the adjustable bridge circuit 20, and the other end of the amplifier circuit 30 is connected to the control circuit 200; one end of the proportional adjustment circuit 40 is connected to the amplifier circuit 30, and the other end of the proportional adjustment circuit 40 is connected to the control circuit 200.

[0022] Specifically, the industrial equipment may include a control circuit 200 and a temperature detection circuit 100. The control circuit 200 may include, but is not limited to, an MCU, for controlling the industrial equipment and the temperature detection circuit 100. For example, the industrial equipment may be a motor, which has an MCU installed inside. The motor and the temperature detection circuit 100 can be controlled by the MCU.

[0023] The temperature detection circuit 100 is connected to the control circuit 200 and is used to detect the motor temperature. It may include a temperature detection device 10, an adjustable bridge circuit 20, an amplifier circuit 30, and a proportional adjustment circuit 40. The temperature detection device 10 may include a resistive sensor whose resistance changes with temperature. Based on the number of resistors, resistive sensors can be divided into single-resistance sensors and multi-resistance sensors. A single-resistance sensor has one thermistor, while a multi-resistance sensor has multiple thermistors connected in series. Single-resistance sensors can be further classified into various types based on their resistance values.

[0024] The adjustable bridge circuit 20 is connected to both the control circuit 200 and the temperature detection device 10. It receives control signals from the control circuit 200 and turns on and off according to these signals. This allows it to adjust its resistance value to adapt to different types of temperature detection devices 10. For example, the resistance value can be adjusted by changing the number of resistors connected to the circuit. Specifically, the number of resistors connected to the adjustable bridge circuit 20 differs when it is on and off. For instance, when the resistance of the temperature detection device 10 is high, the control circuit 200 can turn the adjustable bridge circuit 20 off, reducing the number of resistors connected to the circuit to accommodate the higher resistance of the temperature detection device 10. Conversely, when the resistance of the temperature detection device 10 is low, the control circuit 200 can turn the adjustable bridge circuit 20 on, increasing the number of resistors connected to the circuit to accommodate the lower resistance of the temperature detection device 10.

[0025] The amplifier circuit 30 is connected to both the adjustable bridge circuit 20 and the control circuit 200. It receives the temperature signal output from the temperature detection device 10, amplifies the signal, and outputs it to the control circuit 200, which then confirms the current temperature based on the signal. Simultaneously, the amplifier circuit 30 is connected to a proportional adjustment circuit 40, which allows adjustment of the resistance value of the amplifier circuit 30 to adjust its amplification factor, thus adapting it to different types of temperature detection devices 10. For example, when a lower amplification factor is required, the proportional adjustment circuit 40 can be turned on; when a higher amplification factor is required, the proportional adjustment circuit 40 can be turned off.

[0026] Furthermore, the control signals received by the adjustable bridge circuit 20 and the proportional adjustment circuit 40 can be the same or different. If they are the same, the adjustable bridge circuit 20 and the proportional adjustment circuit 40 can simultaneously turn on and off according to the control signal. If the adjustable bridge circuit 20 and the proportional adjustment circuit 40 are simultaneously turned on to adapt to the first type of temperature detection device 10, and the adjustable bridge circuit 20 and the proportional adjustment circuit 40 are simultaneously turned off to adapt to the second type of temperature detection device 10, then at least two different types of sensors can be adapted. Alternatively, an inverter can be added to the circuit to reverse the conduction states of the adjustable bridge circuit 20 and the proportional adjustment circuit 40. For example, an inverter can be added to the proportional adjustment circuit 40, so that when the adjustable bridge circuit 20 is turned on, the proportional adjustment circuit 40 is turned off, and when the adjustable bridge circuit 20 is turned off, the proportional adjustment circuit 40 is turned on, thus also achieving adaptation to two types of temperature detection devices 10. In the above scenario, the control circuit 200 only requires one GPIO port to connect to the adjustable bridge circuit 20 and the proportional adjustment circuit 40, reducing resource consumption on the control circuit 200. Without considering resource consumption, the control circuit 200 can connect to the adjustable bridge circuit 20 via one GPIO port and to the proportional adjustment circuit 40 via another GPIO port, independently controlling the on / off state of both circuits. Figure 3 GPIO1 is the GPIO port connected to the adjustable bridge circuit 20, and GPIO is the GPIO port connected to the proportional adjustment circuit 40.

[0027] As a further embodiment, the adjustable bridge circuit 20 includes a first switching circuit 21 and a bridge circuit 22; one end of the first switching circuit 21 is connected to the control circuit 200, and the other end of the first switching circuit 21 is connected to the bridge circuit 22, and the bridge circuit 22 is connected to the temperature detection device 10 and the amplification circuit 30 respectively.

[0028] One end of the first switching circuit 21 is connected to the control circuit 200, and is used to turn on and off according to the control signal output by the control circuit 200. The other end of the first switching circuit 21 is connected to the bridge circuit 22, and can change the number of resistors connected to the bridge circuit 22 according to its own on and off state, thereby changing the resistance value of the bridge circuit 22, thus adapting to different types of temperature detection devices 10. For example, the control signal can be a level signal, then the first switching circuit 21 can be turned on according to a first level signal and turned off according to a second level signal, wherein the first level signal can be a high level and the second level signal can be a low level.

[0029] As a further embodiment, the first switching circuit 21 includes a first switching transistor Q1, the controlled terminal of the first switching transistor Q1 is connected to the control circuit 200, the first terminal of the first switching transistor Q1 is grounded, and the second terminal of the first switching transistor Q1 is connected to the bridge circuit 22.

[0030] The first switching circuit 21 may include a first switching transistor Q1, a fifth resistor R5 and a sixth resistor R6. The first switching transistor Q1 may be a MOSFET. The gate of the first switching transistor Q1 is connected to the control circuit 200 through the fifth resistor R5. The source of the first switching transistor Q1 is grounded and the drain of the first switching transistor Q1 is connected to the bridge circuit 22. One end of the sixth resistor R6 is connected to the fifth resistor R5 and the other end of the sixth resistor R6 is grounded.

[0031] The first switch Q1 can be turned on and off according to the control signal of the control circuit 200. The number of resistors connected to the bridge circuit 22 can be adjusted by turning the first switch Q1 on and off, thereby adapting to different temperature detection devices 10.

[0032] As a further embodiment, the bridge circuit 22 includes a first resistor R1, a second resistor R2, a third resistor R3, and a fourth resistor R4; one end of the first resistor R1 and one end of the second resistor R2 are both connected to the power supply terminal, the other end of the first resistor R1 is connected to one end of the third resistor R3, one end of the fourth resistor R4, and the amplifier circuit 30, the other end of the second resistor R2 is connected to the temperature detection device 10, the other end of the third resistor R3 is connected to the second terminal of the first switching transistor Q1, and the other end of the fourth resistor R4 is grounded.

[0033] The bridge circuit 22 may include a first resistor R1, a second resistor R2, a third resistor R3, and a fourth resistor R4, such as... Figure 3 As shown, the thermistor RT can be used as a resistive sensor. One end of the first resistor R1 and the second resistor R2 are both connected to the power supply. The other end of the first resistor R1 is connected to the third resistor R3 and the fourth resistor R4 respectively. The second resistor R2 is connected to the thermistor RT. The first resistor R1, the second resistor R2, the third resistor R3, the fourth resistor R4 and the thermistor RT can form a Wheatstone bridge. The first resistor R1 and the second resistor R2 are fixed matching resistors with the same resistance value. The third resistor R3 and the fourth resistor R4 are adapter resistors. Their resistance values ​​can be adjusted according to the type of thermistor RT and the resistance value corresponding to the sampling temperature range. The resistance value can be further adjusted by whether or not the third resistor R3 is connected. The resistance value of the fourth resistor R4 is not greater than the resistance value corresponding to the lowest temperature of the large resistance sensor.

[0034] like Figure 3 As shown, the first switch Q1 is connected to GPIO1. When the first switch Q1 is on, the third resistor R3 and the fourth resistor R4 are connected in parallel, reducing the bridge arm resistance and allowing it to accommodate a small-value thermistor RT. The resistance of the third resistor R3 and the fourth resistor R4 in parallel is no greater than the resistance corresponding to the lowest temperature of the small-value sensor. When the first switch Q1 is off, the third resistor R3 and the fourth resistor R4 are disconnected, and the bridge circuit only connects to the fourth resistor R4. In this case, the bridge circuit can accommodate a large resistance range.

[0035] As a further embodiment, the proportional adjustment circuit 40 includes a second switching circuit 41 and a voltage divider circuit 42; one end of the voltage divider circuit 42 is connected to the bridge circuit 22 through the amplifier circuit 30, the other end of the voltage divider circuit 42 is connected to the proportional amplifier circuit 32, and the voltage divider circuit 42 is also connected to the second switching circuit 41, which is connected to the control circuit 200.

[0036] The proportional adjustment circuit 40 may include a second switching circuit 41 and a voltage divider circuit 42. One end of the second switching circuit 41 is connected to the control circuit 200, and the other end is connected to the voltage divider circuit 42. The voltage divider circuit 42 is connected to the bridge circuit 22 through the amplifier circuit 30 and is used to adjust the amplification factor. The proportional adjustment circuit 40 can be turned on and off according to the control signal, and the resistance of the voltage divider circuit 42 is changed by turning it on and off, thereby realizing the adjustment of the amplification factor.

[0037] As a further embodiment, the second switching circuit 41 includes a second switching transistor Q2, the controlled terminal of the second switching transistor Q2 is connected to the control circuit 200, the first terminal of the second switching transistor Q2 is grounded, and the second terminal of the second switching transistor Q2 is connected to the voltage divider circuit 42.

[0038] The second switching circuit 41 may include a second switching transistor Q2, an eleventh resistor R11, and a twelfth resistor R12. The voltage divider circuit 42 may include a thirteenth resistor R13 and a fourteenth resistor R14. The filter circuit 33 may include a nineteenth resistor R19 and a first capacitor C1. The second switching transistor Q2 may be a MOSFET. The gate of the second switching transistor Q2 is connected to the control circuit 200 through the eleventh resistor R11. The source of the second switching transistor Q2 is grounded, and the drain of the second switching transistor Q2 is connected to the fourteenth resistor R14. The fourteenth resistor R14 is connected to the thirteenth resistor R13 and the proportional amplifier circuit 32. The thirteenth resistor R13 and the fourteenth resistor R14 constitute the voltage divider circuit 42. The twelfth resistor R12 is connected between the eleventh resistor R11 and the gate of the second switching transistor Q2. One end of the nineteenth resistor R19 is connected to the output terminal of the second operational amplifier U2, and the other end is connected to the first capacitor C1 and the control circuit 200, respectively, for outputting a temperature signal.

[0039] like Figure 3 As shown, the second switch Q2 is connected to GPIO2. When the second switch Q2 is turned on, the fourteenth resistor R14 is connected to the ground terminal, and the voltage divider circuit 42 is activated, which can reduce the signal output by the amplifier circuit 30. When the second switch Q2 is turned off, the fourteenth resistor R14 is disconnected from the ground terminal, and the signal output by the amplifier circuit 30 directly passes through the thirteenth resistor R13 and the fifteenth resistor R15, thereby realizing the adjustment of the amplification factor.

[0040] As a further embodiment, the amplifier circuit 30 includes a differential amplifier circuit 31, a proportional amplifier circuit 32, and a filter circuit 33; one end of the differential amplifier circuit 31 is connected to the bridge circuit 22, the other end of the differential amplifier circuit 31 is connected to one end of the proportional amplifier circuit 32 through the voltage divider circuit 42, the other end of the proportional amplifier circuit 32 is connected to one end of the filter circuit 33, and the other end of the filter circuit 33 is connected to the control circuit 200.

[0041] The amplifier circuit 30 may include a differential amplifier circuit 31, a proportional amplifier circuit 32, and a filter circuit 33. One end of the differential amplifier circuit 31 is connected to the bridge circuit 22, and the other end is connected to the proportional amplifier circuit 32 through the voltage divider circuit 42. The proportional amplifier circuit 32 is connected to the filter circuit 33, so that the temperature signal can be amplified by the two-stage amplifier circuit 30, and then the amplified temperature signal is output to the control circuit 200 through the filter circuit 33.

[0042] The input signal of the differential amplifier circuit 31 is the differential voltage signal of the bridge circuit 22. It amplifies the differential voltage signal for processing by subsequent circuits and suppresses common-mode noise to improve the signal-to-noise ratio of the differential voltage signal. The input signal of the proportional amplifier circuit 32 is the output signal of the differential amplifier circuit 31. It further amplifies the differentially amplified signal to the effective acquisition range of the ADC circuit (such as 0~3.3V or 0~5V of the MCU's built-in ADC). Furthermore, the amplification factor can be adjusted by changing the conduction state of the voltage divider circuit 42, ensuring that the output signals of different types of temperature detection devices 10 can be accurately acquired by the ADC. The input signal of the filter circuit 33 is the output signal of the proportional amplifier circuit 32. It is used to filter out high-frequency noise, such as circuit parasitic oscillations and interference signals introduced by electromagnetic radiation, making the final output temperature signal smoother and more stable, avoiding noise-induced ADC acquisition errors, and ensuring the accuracy of temperature detection.

[0043] As a further embodiment, the differential amplifier circuit 31 includes a first operational amplifier U1, the non-inverting input terminal and the inverting input terminal of the first operational amplifier U1 are respectively connected to different arms of the bridge circuit 22, and the output terminal of the first operational amplifier U1 is connected to the proportional amplifier circuit 32 through the voltage divider circuit 42.

[0044] The differential amplifier circuit 31 may include a first operational amplifier U1, a seventh resistor R7, an eighth resistor R8, a ninth resistor R9, and a tenth resistor R10. For example... Figure 3 As shown, one end of the seventh resistor R7 is connected to one arm of the bridge circuit 22, namely the second resistor R2. One end of the ninth resistor R9 is connected to the other arm of the bridge circuit 22, namely the first resistor R1. The other end of the seventh resistor R7 is connected to the non-inverting input of the first operational amplifier U1. The other end of the ninth resistor R9 is connected to the inverting input of the first operational amplifier U1. The eighth resistor R8 is connected between the seventh resistor R7 and the non-inverting input of the first operational amplifier U1. The output of the first operational amplifier U1 is connected to its inverting input through the tenth resistor R10. The output of the first operational amplifier U1 is also connected to the voltage divider circuit 42.

[0045] The first operational amplifier U1 can amplify the differential voltage signal output by the bridge circuit 22 and suppress the common-mode noise of the differential voltage signal to improve the signal-to-noise ratio of the differential voltage signal. The amplified differential voltage signal is then output to the proportional amplifier circuit 32 via the voltage divider circuit 42.

[0046] As a further embodiment, the proportional amplifier circuit 32 includes a second operational amplifier U2, the non-inverting input terminal of the second operational amplifier U2 is connected to the differential amplifier circuit 31 through the voltage divider circuit 42, the inverting input terminal of the second operational amplifier U2 is connected to the output terminal of the second operational amplifier U2, and the output terminal of the second operational amplifier U2 is connected to the filter circuit 33.

[0047] The proportional amplifier circuit 32 may include a second operational amplifier U2, a fifteenth resistor R15, a sixteenth resistor R16, a seventeenth resistor R17, and an eighteenth resistor R18. For example... Figure 3 As shown, the non-inverting input of the second operational amplifier U2 is connected to the fifteenth resistor R15, the sixteenth resistor R16 and the voltage divider circuit 42, respectively. Its inverting input is connected to the seventeenth resistor R17 and the eighteenth resistor R18, respectively. Its output is connected to the filter circuit 33 and the eighteenth resistor R18, respectively.

[0048] The second operational amplifier U2 can further amplify the differentially amplified signal to the effective acquisition range of the ADC. At the same time, the amplification factor can be flexibly adjusted through the voltage divider circuit 42 to ensure that the output signals of different types of temperature detection devices 10 can be accurately acquired by the ADC.

[0049] like Figure 3 As shown, the second switch Q2 is connected to GPIO2. When the second switch Q2 is turned on, the fourteenth resistor R14 is connected to the ground terminal, and the voltage divider circuit 42 is activated. The signal output from the first operational amplifier U1 is amplified by the voltage divider circuit 42 and then output to the second operational amplifier U2. When the second switch Q2 is turned off, the fourteenth resistor R14 is disconnected from the ground terminal, and the signal output from the first operational amplifier U1 directly enters the second operational amplifier U2 through the thirteenth resistor R13 and the fifteenth resistor R15, thereby enabling adjustment of the amplification factor. The signal output from the second operational amplifier U2 is filtered by the nineteenth resistor R19 and the first capacitor C1 and then output to the control circuit 200, as shown. Figure 3 As shown, Figure 3 Temp_AD is the temperature signal after being filtered by filter circuit 33.

[0050] This utility model also provides an industrial device, which includes a control circuit 200 and a temperature detection circuit 100 as described in any of the above embodiments; the temperature detection circuit 100 includes a temperature detection device 10, an adjustable bridge circuit 20, an amplifier circuit 30, and a proportional adjustment circuit 40; the adjustable bridge circuit 20 is connected to the temperature detection device 10, and one end of the adjustable bridge circuit 20 is connected to the control circuit 200 of the industrial device; one end of the amplifier circuit 30 is connected to the other end of the adjustable bridge circuit 20, and the other end of the amplifier circuit 30 is connected to the control circuit 200; one end of the proportional adjustment circuit 40 is connected to the amplifier circuit 30, and the other end of the proportional adjustment circuit 40 is connected to the control circuit 200.

[0051] Specifically, the industrial equipment may include a control circuit 200 and a temperature detection circuit 100. The control circuit 200 may include, but is not limited to, an MCU, for controlling the industrial equipment and the temperature detection circuit 100. For example, the industrial equipment may be a motor, which has an MCU installed inside. The motor and the temperature detection circuit 100 can be controlled by the MCU.

[0052] The temperature detection circuit 100 is connected to the control circuit 200 and is used to detect the motor temperature. It may include a temperature detection device 10, an adjustable bridge circuit 20, an amplifier circuit 30, and a proportional adjustment circuit 40. The temperature detection device 10 may include a resistive sensor whose resistance changes with temperature. Based on the number of resistors, resistive sensors can be divided into single-resistance sensors and multi-resistance sensors. A single-resistance sensor has one thermistor, while a multi-resistance sensor has multiple thermistors connected in series. Single-resistance sensors can be further classified into various types based on their resistance values.

[0053] The adjustable bridge circuit 20 is connected to both the control circuit 200 and the temperature detection device 10. It receives control signals from the control circuit 200 and turns on and off according to these signals. This allows it to adjust its resistance value to adapt to different types of temperature detection devices 10. For example, the resistance value can be adjusted by changing the number of resistors connected to the circuit. Specifically, the number of resistors connected to the adjustable bridge circuit 20 differs when it is on and off. For instance, when the resistance of the temperature detection device 10 is high, the control circuit 200 can turn the adjustable bridge circuit 20 off, reducing the number of resistors connected to the circuit to accommodate the higher resistance of the temperature detection device 10. Conversely, when the resistance of the temperature detection device 10 is low, the control circuit 200 can turn the adjustable bridge circuit 20 on, increasing the number of resistors connected to the circuit to accommodate the lower resistance of the temperature detection device 10.

[0054] The amplifier circuit 30 is connected to both the adjustable bridge circuit 20 and the control circuit 200. It receives the temperature signal output from the temperature detection device 10, amplifies the signal, and outputs it to the control circuit 200, which then confirms the current temperature based on the signal. Simultaneously, the amplifier circuit 30 is connected to a proportional adjustment circuit 40, which allows adjustment of the resistance value of the amplifier circuit 30 to adjust its amplification factor, thus adapting it to different types of temperature detection devices 10. For example, when a lower amplification factor is required, the proportional adjustment circuit 40 can be turned on; when a higher amplification factor is required, the proportional adjustment circuit 40 can be turned off.

[0055] Furthermore, the control signals received by the adjustable bridge circuit 20 and the proportional adjustment circuit 40 can be the same or different. If they are the same, the adjustable bridge circuit 20 and the proportional adjustment circuit 40 can simultaneously turn on and off according to the control signal. If the adjustable bridge circuit 20 and the proportional adjustment circuit 40 are simultaneously turned on to adapt to the first type of temperature detection device 10, and the adjustable bridge circuit 20 and the proportional adjustment circuit 40 are simultaneously turned off to adapt to the second type of temperature detection device 10, then at least two different types of sensors can be adapted. Alternatively, an inverter can be added to the circuit to reverse the conduction states of the adjustable bridge circuit 20 and the proportional adjustment circuit 40. For example, an inverter can be added to the proportional adjustment circuit 40, so that when the adjustable bridge circuit 20 is turned on, the proportional adjustment circuit 40 is turned off, and when the adjustable bridge circuit 20 is turned off, the proportional adjustment circuit 40 is turned on, thus also achieving adaptation to two types of temperature detection devices 10. In the above scenario, the control circuit 200 only requires one GPIO port to connect to the adjustable bridge circuit 20 and the proportional adjustment circuit 40, reducing resource consumption on the control circuit 200. Without considering resource consumption, the control circuit 200 can connect to the adjustable bridge circuit 20 via one GPIO port and to the proportional adjustment circuit 40 via another GPIO port, independently controlling the on / off state of both circuits. Figure 3 GPIO1 is the GPIO port connected to the adjustable bridge circuit 20, and GPIO is the GPIO port connected to the proportional adjustment circuit 40.

[0056] The temperature detection circuit and industrial equipment disclosed in this utility model can adapt to at least two types of temperature detection devices by changing the conduction state of the adjustable bridge circuit and the proportional adjustment circuit, and thus can be compatible with a variety of temperature detection devices. This not only reduces replacement costs but also improves convenience.

[0057] The above description is merely a specific embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this utility model, and these modifications or substitutions should all be covered within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the scope of the claims.

Claims

1. A temperature detection circuit, characterized in that, The temperature detection circuit includes: Temperature detection device; An adjustable bridge circuit is provided, wherein the adjustable bridge circuit is connected to the temperature detection device, and one end of the adjustable bridge circuit is connected to the control circuit. An amplifier circuit, one end of which is connected to the other end of the adjustable bridge circuit, and the other end of which is connected to the control circuit; A proportional adjustment circuit, one end of which is connected to the amplifier circuit, and the other end of which is connected to the control circuit.

2. The temperature detection circuit as described in claim 1, characterized in that, The adjustable bridge circuit includes a first switching circuit and a bridge circuit. One end of the first switching circuit is connected to the control circuit, and the other end of the first switching circuit is connected to the bridge circuit. The bridge circuit is connected to the temperature detection device and the amplification circuit, respectively.

3. The temperature detection circuit as described in claim 2, characterized in that, The first switching circuit includes a first switching transistor, the controlled terminal of the first switching transistor is connected to the control circuit, the first terminal of the first switching transistor is grounded, and the second terminal of the first switching transistor is connected to the bridge circuit.

4. The temperature detection circuit as described in claim 3, characterized in that, The bridge circuit includes a first resistor, a second resistor, a third resistor, and a fourth resistor; One end of the first resistor and one end of the second resistor are both connected to the power supply terminal. The other end of the first resistor is connected to one end of the third resistor, one end of the fourth resistor, and the amplifier circuit, respectively. The other end of the second resistor is connected to the temperature detection device. The other end of the third resistor is connected to the second terminal of the first switching transistor. The other end of the fourth resistor is grounded.

5. The temperature detection circuit as described in claim 2, characterized in that, The proportional adjustment circuit includes a second switching circuit and a voltage divider circuit; One end of the voltage divider circuit is connected to the bridge circuit through the amplifier circuit, and the other end of the voltage divider circuit is connected to the amplifier circuit. The voltage divider circuit is also connected to the second switch circuit, and the second switch circuit is connected to the control circuit.

6. The temperature detection circuit as described in claim 5, characterized in that, The second switching circuit includes a second switching transistor, the controlled terminal of the second switching transistor is connected to the control circuit, the first terminal of the second switching transistor is grounded, and the second terminal of the second switching transistor is connected to the voltage divider circuit.

7. The temperature detection circuit as described in claim 5, characterized in that, The amplifier circuit includes a differential amplifier circuit, a proportional amplifier circuit, and a filter circuit. One end of the differential amplifier circuit is connected to the bridge circuit, the other end of the differential amplifier circuit is connected to one end of the proportional amplifier circuit through the voltage divider circuit, the other end of the proportional amplifier circuit is connected to one end of the filter circuit, and the other end of the filter circuit is connected to the control circuit.

8. The temperature detection circuit as described in claim 7, characterized in that, The differential amplifier circuit includes a first operational amplifier, the non-inverting input terminal and the inverting input terminal of the first operational amplifier are respectively connected to different arms of the bridge circuit, and the output terminal of the first operational amplifier is connected to the proportional amplifier circuit through the voltage divider circuit.

9. The temperature detection circuit as described in claim 7, characterized in that, The proportional amplifier circuit includes a second operational amplifier. The non-inverting input of the second operational amplifier is connected to the differential amplifier circuit through the voltage divider circuit. The inverting input of the second operational amplifier is connected to the output of the second operational amplifier. The output of the second operational amplifier is connected to the filter circuit.

10. An industrial device, characterized in that, The industrial equipment includes a control circuit and a temperature detection circuit as described in any one of claims 1-9.

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