Motor temperature detection circuit and electronic equipment

Abstract

The invention provides a motor temperature detection circuit and electronic equipment, the motor temperature detection circuit adopts a current source module to output stable current, a micro-control unit detects the type and resistance interval of a temperature sensor module, and the magnitude of current flowing through a temperature sensor is controlled and regulated through a resistance interval gating module. The temperature analysis precision of different resistance value interval sensor types and temperature intervals corresponding to different resistance value intervals is improved, so that the precision of the acquisition circuit is improved, the differential amplification module ensures stable acquisition of the voltage acquisition end of the micro-control unit, and the problems that the acquisition circuit in the existing scheme is mostly suitable for a single sensor type and the acquisition cost is low are solved. And for temperature sensors with different types and large resistance interval spans, the detection precision is poor.

Description

Technical Field

[0001] The present application relates to the technical field of motor temperature detection, and in particular to a motor temperature detection circuit and electronic equipment. Background Art

[0002] During the operation of electric vehicles, the electric drive part, especially the motor and IGBT, will generate a lot of heat. If the temperature is not controlled accurately and the heat is not dissipated in time, the electric drive components will suffer thermal failure, which may even cause safety problems in severe cases.

[0003] At present, most of them use the traditional motor temperature sampling circuit, which connects the temperature sensor in series and parallel with the resistor to form a voltage divider circuit. When the sensor resistance changes, the resistance of the series and parallel circuit changes accordingly, and the motor temperature is calculated by the voltage divider value. Furthermore, in order to improve the accuracy of the acquisition circuit, a constant current source circuit will be added. A constant current flows through the temperature sensor. When the sensor resistance changes, a changing voltage value is output, thereby calculating a more accurate motor temperature.

[0004] However, currently commonly used temperature sensors include NTC, PT100, PT1000 and other types. The acquisition circuits of existing solutions are mostly suitable for a single sensor type. For temperature sensors of different types and with a large resistance range, the detection accuracy is poor. Summary of the invention

[0005] The main purpose of the present application is to provide a motor temperature detection circuit and electronic device, so as to at least solve the problem that the acquisition circuit of the existing solution is mostly suitable for a single sensor type, and the detection accuracy is poor for temperature sensors of different types and with a wide resistance range.

[0006] In order to achieve the above object, according to one aspect of the present application, a motor temperature detection circuit is provided, and the motor temperature detection circuit includes:

[0007] Current source module;

[0008] A temperature sensor module, electrically connected to the current source module, and used to detect the temperature of the motor;

[0009] A resistance range gating module, comprising a conduction end, a first selection end, a second selection end and a third selection end, wherein the conduction end of the resistance range gating module is electrically connected to the temperature sensor module;

[0010] A differential amplifier module, having an input end and an output end, wherein the input end of the differential amplifier module is electrically connected to the conduction end of the resistance range selection module;

[0011] A microcontrol unit comprises a voltage collection end, a first control end, a second control end and a third control end. The voltage collection end of the microcontrol unit is electrically connected to the output end of the differential amplifier module, the first control end of the microcontrol unit is electrically connected to the first selection end of the resistance range gating module, the second control end of the microcontrol unit is electrically connected to the second selection end of the resistance range gating module, and the third control end of the microcontrol unit is electrically connected to the third selection end of the resistance range gating module.

[0012] Optionally, the current source module includes a first operational amplifier, a second operational amplifier, a voltage source, a first constant current source resistor module, a second constant current source resistor module, a third constant current source resistor module, a fourth constant current source resistor module and a fifth constant current source resistor module, the inverting input terminal of the first operational amplifier is electrically connected to the first end of the first constant current source resistor module and the first end of the second constant current source resistor module, respectively, the voltage source is electrically connected to the first end of the third constant current source resistor module, the in-phase input terminal of the first operational amplifier is electrically connected to the second end of the third constant current source resistor module and the second end of the fourth constant current source resistor module, respectively, the output terminal of the first operational amplifier is electrically connected to the second end of the second constant current source resistor module and the first end of the fifth constant current source resistor module, the in-phase input terminal of the second operational amplifier is electrically connected to the second end of the fifth constant current source resistor module and the current source module, the inverting input terminal of the second operational amplifier is electrically connected to the output terminal of the second operational amplifier and the first end of the fourth constant current source resistor module, and the second end of the first constant current source resistor module is grounded.

[0013] Optionally, the temperature sensor module includes a resistance-type temperature sensor and a first regulating resistor module, and the resistance range gating module includes a second regulating resistor module, a third regulating resistor module, a fourth regulating resistor module, a first power switch, a second power switch and a third power switch, the first end of the first regulating resistor module is electrically connected to the current source module, the first end of the second regulating resistor module, the first end of the third regulating resistor module and the first end of the fourth regulating resistor module respectively, the second end of the first regulating resistor module is electrically connected to the first end of the resistance-type temperature sensor, the second end of the second regulating resistor module is electrically connected to the drain of the first power switch, the second end of the third regulating resistor module is electrically connected to the drain of the second power switch, the second end of the fourth regulating resistor module is electrically connected to the drain of the third power switch, the gate of the first power switch is electrically connected to the first control end of the micro control unit, the gate of the second power switch is electrically connected to the second control end of the micro control unit, the gate of the third power switch is electrically connected to the third control end of the micro control unit, and the source of the first power switch, the source of the second power switch, the source of the third power switch and the second end of the resistance-type temperature sensor are grounded respectively.

[0014] Optionally, the differential amplifier module includes a third op amp, a first op amp resistor module, a second op amp resistor module, a third op amp resistor module and a fourth op amp resistor module, the first end of the first op amp resistor module is electrically connected to the first end of the first adjustment resistor module, the second end of the first op amp resistor module is electrically connected to the second end of the third op amp resistor module and the in-phase input end of the third op amp, respectively, the inverting input end of the third op amp is electrically connected to the second end of the second op amp resistor module and the first end of the fourth op amp resistor module, respectively, the output ends of the three op amps are electrically connected to the second end of the fourth op amp resistor module and the voltage collection end of the micro control unit, and the first end of the second op amp resistor module and the first end of the third op amp resistor module are grounded, respectively.

[0015] Optionally, the micro control unit is used to perform the following steps:

[0016] When the first power switch is turned on,

[0017] according to Determining the resistance value of the resistance temperature sensor;

[0018] When the second power switch is turned on,

[0019] according to Determining the resistance value of the resistance temperature sensor;

[0020] When the third power switch is turned on,

[0021] according to Determining the resistance value of the resistance temperature sensor;

[0022] Among them, RX is the resistance type temperature sensor, R5 is the fifth constant current source resistor module of the current source module, the second end of the fifth constant current source resistor module is electrically connected to the first end of the first adjustment resistor module, R6 is the first adjustment resistor module, R7 is the second adjustment resistor module, R8 is the third adjustment resistor module, R9 is the fourth adjustment resistor module, R12 is the third op amp resistor module, Vo is the collection voltage, the collection voltage is the voltage collected by the voltage collection end of the micro control unit, and VCC is the voltage source of the current source module.

[0023] Optionally, the temperature detection circuit further includes a filter module, and the filter module is electrically connected between a voltage collection terminal of the micro control unit and an output terminal of the differential amplifier module.

[0024] Optionally, the filter module includes a first filter capacitor module and a filter resistor module, the first end of the filter resistor module is electrically connected to the output end of the differential amplifier module, the second end of the filter resistor module is electrically connected to the second end of the first filter capacitor module and the voltage collection end of the micro control unit respectively, and the first end of the first filter capacitor module is grounded.

[0025] Optionally, the temperature detection circuit also includes a second filter capacitor module, a first end of the second filter capacitor module is electrically connected to the conduction end of the resistance range selection module and the input end of the differential amplifier module, and a second end of the second filter capacitor module is grounded.

[0026] Optionally, the first power switch, the second power switch and the third power switch are all NMOS.

[0027] According to another aspect of the present application, an electronic device is provided, and the electronic device includes: any one of the motor temperature detection circuits described above.

[0028] By applying the technical solution of the present application, a current source module is used to output a stable current, a microcontroller unit detects the type and resistance range of the temperature sensor module, and a resistance range selection module is used to control and regulate the current flowing through the temperature sensor, thereby improving the temperature resolution accuracy for different resistance range sensor types and different resistance range corresponding temperature ranges, thereby improving the accuracy of the acquisition circuit, and the differential amplifier module ensures the stable acquisition of the voltage acquisition end of the microcontroller unit, thereby solving the problem that the acquisition circuit of the existing solution is mostly suitable for a single sensor type, and the detection accuracy is poor for temperature sensors of different types and with a large resistance range span. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The drawings constituting part of the present application are used to provide a further understanding of the present application. The exemplary embodiments and descriptions of the present application are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0030] Figure 1 A first schematic diagram of a motor temperature detection circuit provided in an embodiment of the present application is shown;

[0031] Figure 2 A second schematic diagram of a motor temperature detection circuit provided in an embodiment of the present application is shown.

[0032] The above drawings include the following reference numerals:

[0033] 100. Current source module; 200. Temperature sensor module; 300. Resistance range selection module; 400. Differential amplifier module; 500. Micro control unit; 600. Filter module. DETAILED DESCRIPTION

[0034] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0035] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present application.

[0036] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequential order. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present application described here. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0037] As introduced in the background technology, at present, most of them use the traditional motor temperature sampling circuit, which connects the temperature sensor in series and parallel with the resistor to form a voltage divider circuit. When the sensor resistance changes, the resistance of the series and parallel circuit changes accordingly, and the motor temperature is calculated by the voltage divider value. Furthermore, in order to improve the accuracy of the acquisition circuit, a constant current source circuit will be added, and a constant current will flow through the temperature sensor. When the sensor resistance changes, a changing voltage value will be output, so as to calculate a more accurate motor temperature. In order to solve the problem that the acquisition circuit of the existing solution is mostly suitable for a single sensor type, and the detection accuracy of temperature sensors with different types and a large resistance range span is poor, the embodiments of the present application provide a motor temperature detection circuit and electronic equipment.

[0038] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0039] The present application provides a motor temperature detection circuit, such as Figure 1 As shown, the motor temperature detection circuit includes:

[0040] Current source module 100;

[0041] A temperature sensor module 200 is electrically connected to the current source module 100 , and the temperature sensor module 200 is used to detect the temperature of the motor;

[0042] The resistance range gating module 300 has a conduction end, a first selection end, a second selection end and a third selection end, and the conduction end of the resistance range gating module 300 is electrically connected to the temperature sensor module 200;

[0043] The differential amplifier module 400 has an input end and an output end, and the input end of the differential amplifier module 400 is electrically connected to the conduction end of the resistance range selection module 300;

[0044] The micro control unit 500 has a voltage collection end, a first control end, a second control end and a third control end. The voltage collection end of the micro control unit 500 is electrically connected to the output end of the differential amplifier module 400, the first control end of the micro control unit 500 is electrically connected to the first selection end of the resistance range selection module 300, the second control end of the micro control unit 500 is electrically connected to the second selection end of the resistance range selection module 300, and the third control end of the micro control unit 500 is electrically connected to the third selection end of the resistance range selection module 300.

[0045] The above-mentioned motor temperature detection circuit adopts a current source module to output a stable current. The microcontroller unit detects the type and resistance range of the temperature sensor module, and controls the current flowing through the temperature sensor through the resistance range selection module, thereby improving the temperature analysis accuracy for different resistance range sensor types and different resistance range corresponding temperature ranges, thereby improving the accuracy of the acquisition circuit, and the differential amplifier module ensures the stable acquisition of the voltage acquisition end of the microcontroller unit, thereby solving the problem that the acquisition circuit of the existing solution is mostly suitable for a single sensor type, and the detection accuracy is poor for temperature sensors with different types and a large resistance range span.

[0046] In one embodiment of the present application, Figure 2As shown, the current source module 100 includes a first operational amplifier U1, a second operational amplifier U2, a voltage source VCC, a first constant current source resistor module R1, a second constant current source resistor module R2, a third constant current source resistor module R3, a fourth constant current source resistor module R4 and a fifth constant current source resistor module R5, the inverting input terminal of the first operational amplifier U1 is electrically connected to the first end of the first constant current source resistor module R1 and the first end of the second constant current source resistor module R2, the voltage source VCC is electrically connected to the first end of the third constant current source resistor module R3, the non-inverting input terminal of the first operational amplifier U1 is electrically connected to the third constant current source resistor module R5, and the inverting input terminal of the first operational amplifier U1 is electrically connected to the first end of the first constant current source resistor module R1 and the first end of the second constant current source resistor module R2. The second end of the resistance module R3 is electrically connected to the second end of the fourth constant current source resistance module R4, the output end of the first operational amplifier U1 is electrically connected to the second end of the second constant current source resistance module R2 and the first end of the fifth constant current source resistance module R5, the in-phase input end of the second operational amplifier U2 is electrically connected to the second end of the fifth constant current source resistance module R5 and the current source module 100, the inverting input end of the second operational amplifier U2 is electrically connected to the output end of the second operational amplifier U2 and the first end of the fourth constant current source resistance module R4, and the second end of the first constant current source resistance module R1 is grounded.

[0047] Specifically, the first operational amplifier U1, the second operational amplifier U2, the voltage source VCC, the first constant current source resistor module R1, the second constant current source resistor module R2, the third constant current source resistor module R3, the fourth constant current source resistor module R4 and the fifth constant current source resistor module R5, so that the current source module continuously outputs a stable current.

[0048] In one embodiment of the present application, Figure 2As shown, the temperature sensor module 200 includes a resistance-type temperature sensor RX and a first regulating resistor module R6, the resistance range selection module 300 includes a second regulating resistor module R7, a third regulating resistor module R8, a fourth regulating resistor module R9, a first power switch Q1, a second power switch Q2 and a third power switch Q3, the first end of the first regulating resistor module R6 is electrically connected to the current source module 100, the first end of the second regulating resistor module R7, the first end of the third regulating resistor module R8 and the first end of the fourth regulating resistor module R9, respectively, the second end of the first regulating resistor module R6 is electrically connected to the first end of the resistance-type temperature sensor RX, and the second end of the second regulating resistor module R7 is electrically connected to the first end of the resistance-type temperature sensor RX. The first power switch Q1 is electrically connected to the drain of the first power switch Q1, the second end of the third regulating resistor module R8 is electrically connected to the drain of the second power switch Q2, the second end of the fourth regulating resistor module R9 is electrically connected to the drain of the third power switch Q3, the gate of the first power switch Q1 is electrically connected to the first control end of the micro control unit 500, the gate of the second power switch Q2 is electrically connected to the second control end of the micro control unit 500, the gate of the third power switch Q3 is electrically connected to the third control end of the micro control unit 500, and the source of the first power switch Q1, the source of the second power switch Q2, the source of the third power switch Q3 and the second end of the resistance-type temperature sensor RX are grounded respectively.

[0049] Specifically, according to the type of the resistive temperature sensor, different power switches are turned on to change the current flowing through the resistive temperature sensor, that is, the current flowing through the resistive temperature sensor is controlled and regulated by three power switches, thereby improving the temperature resolution accuracy for sensor types with different resistance ranges and temperature ranges corresponding to different resistance ranges, thereby improving the accuracy of the acquisition circuit.

[0050] Depending on the position where the resistance temperature sensor is installed on the motor, the temperature of different structures of the motor can be detected, such as the winding temperature of the motor and the bearing temperature of the motor.

[0051] In one embodiment of the present application, Figure 2As shown, the differential amplifier module 400 includes a third operational amplifier U3, a first operational amplifier resistor module R10, a second operational amplifier resistor module R11, a third operational amplifier resistor module R12 and a fourth operational amplifier resistor module R13. The first end of the first operational amplifier resistor module R10 is electrically connected to the first end of the first regulating resistor module R6, the second end of the first operational amplifier resistor module R10 is electrically connected to the second end of the third operational amplifier resistor module R12 and the non-inverting input end of the third operational amplifier U3, the inverting input end of the third operational amplifier U3 is electrically connected to the second end of the second operational amplifier resistor module R11 and the first end of the fourth operational amplifier resistor module R13, the output ends of the three operational amplifiers are electrically connected to the second end of the fourth operational amplifier resistor module R13 and the voltage collection end of the micro control unit 500, and the first end of the second operational amplifier resistor module R11 and the first end of the third operational amplifier resistor module R12 are grounded.

[0052] Specifically, the third operational amplifier U3, the first operational amplifier resistor module R10, the second operational amplifier resistor module R11, the third operational amplifier resistor module R12 and the fourth operational amplifier resistor module R13 are used to realize the differential amplification function, thereby ensuring the stable acquisition of the voltage acquisition end of the micro control unit.

[0053] In one embodiment of the present application, Figure 2 As shown, the temperature detection circuit further includes a filter module 600 , and the filter module 600 is electrically connected between the voltage collection terminal of the micro control unit 500 and the output terminal of the differential amplifier module 400 .

[0054] Specifically, the filter module is used to filter the voltage output by the differential amplifier module.

[0055] In one embodiment of the present application, Figure 2 As shown, the above-mentioned filter module 600 includes a first filter capacitor module C2 and a filter resistor module R14, the first end of the above-mentioned filter resistor module R14 is electrically connected to the output end of the above-mentioned differential amplifier module 400, the second end of the above-mentioned filter resistor module R14 is electrically connected to the second end of the above-mentioned first filter capacitor module C2 and the voltage collection end of the above-mentioned micro control unit 500, and the first end of the above-mentioned first filter capacitor module C2 is grounded.

[0056] Specifically, the first filter capacitor module C2 and the filter resistor module R14 form an RC filter circuit, thereby improving the filtering effect.

[0057] In one embodiment of the present application, Figure 2As shown, the temperature detection circuit further includes a second filter capacitor module C1, a first end of the second filter capacitor module C1 is electrically connected to the conduction end of the resistance range selection module 300 and the input end of the differential amplifier module 400, and a second end of the second filter capacitor module C1 is grounded.

[0058] Specifically, each capacitor module includes a plurality of capacitors connected in parallel or in series, and the second filter capacitor module is used to filter the voltage at the conduction end of the resistance range selection module.

[0059] In one embodiment of the present application, the first power switch, the second power switch and the third power switch are all NMOS.

[0060] Each resistor module may include a plurality of resistors connected in parallel or in series.

[0061] In one embodiment of the present application, the micro control unit is used to perform the following steps:

[0062] When the first power switch is turned on,

[0063] According to formula 1: Determining the resistance value of the above-mentioned resistance temperature sensor;

[0064] When the second power switch is turned on,

[0065] According to formula 2: Determining the resistance value of the above-mentioned resistance temperature sensor;

[0066] When the third power switch is turned on,

[0067] According to formula 3: Determining the resistance value of the above-mentioned resistance temperature sensor;

[0068] Among them, RX is the above-mentioned resistance type temperature sensor, R5 is the fifth constant current source resistor module of the above-mentioned current source module, the second end of the above-mentioned fifth constant current source resistor module is electrically connected to the first end of the above-mentioned first adjustment resistor module, R6 is the first adjustment resistor module, R7 is the second adjustment resistor module, R8 is the third adjustment resistor module, R9 is the fourth adjustment resistor module, R12 is the above-mentioned third op amp resistor module, Vo is the collection voltage, the above-mentioned collection voltage is the voltage collected by the voltage collection end of the above-mentioned micro control unit, and VCC is the voltage source of the above-mentioned current source module.

[0069] Look up the relationship between the resistance values ​​of PT100, PT1000, NTC, etc. at the current temperature, and confirm the current temperature sensor type (for example, at 25°C, the resistance value of PT100 is 109.7 ohms, the resistance value of PT1000 is 1097 ohms, and the resistance value of NTC is 5000 ohms);

[0070] 0 to 500 ohms is listed as the first resistance range, which includes the high temperature resistance of PT100 and NTC. At this time, Q1 is selected, and the resistance value of the resistance temperature sensor is analyzed as Formula 1;

[0071] 600 to 2500 ohms is listed as the second resistance range, which includes the resistance of PT1000 and NTC at normal temperature. At this time, Q2 is selected, and the resistance of the resistance temperature sensor is analyzed as formula 2;

[0072] 2500 to 500k ohms is listed as the third resistance range, which includes the low temperature resistance of the NTC. At this time, Q3 is selected, and the resistance of the resistance temperature sensor is analyzed as Formula 3.

[0073] The current source module outputs current Io, and the current formula is:

[0074]

[0075] Let R10 = R11, R12 = R3, Q1 is turned on, Q2 and Q3 are not turned on, then the output Vo (i.e. the voltage collected by the voltage collection terminal of the micro control unit) is:

[0076]

[0077] Q2 is conducting, Q1 and Q3 are not conducting, and the output Vo is:

[0078]

[0079] Q3 is conducting, Q1 and Q2 are not conducting, and the output Vo is:

[0080]

[0081] The present application also provides an electronic device, which includes: any one of the above-mentioned motor temperature detection circuits. A current source module is used to output a stable current, a microcontroller unit detects the type and resistance range of the temperature sensor module, and a resistance range selection module is used to control and regulate the current flowing through the temperature sensor, thereby improving the temperature resolution accuracy for different resistance range sensor types and temperature ranges corresponding to different resistance ranges, thereby improving the accuracy of the acquisition circuit, and the differential amplifier module ensures the stable acquisition of the voltage acquisition end of the microcontroller unit, thereby solving the problem that the acquisition circuit of the existing solution is mostly suitable for a single sensor type, and the detection accuracy is poor for temperature sensors of different types and with a large resistance range span.

[0082] It should be noted that the above electrical connection can be a direct electrical connection or an indirect electrical connection. Direct electrical connection means that two devices are directly connected, and indirect electrical connection means that other devices such as capacitors and resistors are also connected between the connected A and B.

[0083] It should also be noted that the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, commodity or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, commodity or device. In the absence of more restrictions, the elements defined by the sentence "comprises a ..." do not exclude the existence of other identical elements in the process, method, commodity or device including the elements.

[0084] From the above description, it can be seen that the above embodiments of the present application achieve the following technical effects:

[0085] 1) The motor temperature detection circuit of the present application adopts a current source module to output a stable current. The microcontroller unit detects the type and resistance range of the temperature sensor module, and controls the current flowing through the temperature sensor through the resistance range selection module, thereby improving the temperature analysis accuracy for different resistance range sensor types and different resistance range corresponding temperature ranges, thereby improving the accuracy of the acquisition circuit, and the differential amplifier module ensures the stable acquisition of the voltage acquisition end of the microcontroller unit, thereby solving the problem that the acquisition circuit of the existing solution is mostly suitable for a single sensor type, and the detection accuracy is poor for temperature sensors of different types and with a large resistance range span.

[0086] 2) The electronic device of the present application adopts a current source module to output a stable current, and a microcontroller unit detects the type and resistance range of the temperature sensor module, and controls and regulates the current flowing through the temperature sensor through a resistance range selection module, thereby improving the temperature analysis accuracy for different resistance range sensor types and different resistance range corresponding temperature ranges, thereby improving the accuracy of the acquisition circuit, and the differential amplifier module ensures the stable acquisition of the voltage acquisition end of the microcontroller unit, thereby solving the problem that the acquisition circuit of the existing solution is mostly suitable for a single sensor type, and the detection accuracy is poor for temperature sensors of different types and with a large resistance range span.

[0087] The above description is only the preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A motor temperature detection circuit, characterized in that: include: Current source module; A temperature sensor module, electrically connected to the current source module, and used to detect the temperature of the motor; A resistance range gating module, comprising a conduction end, a first selection end, a second selection end and a third selection end, wherein the conduction end of the resistance range gating module is electrically connected to the temperature sensor module; A differential amplifier module, having an input end and an output end, wherein the input end of the differential amplifier module is electrically connected to the conduction end of the resistance range selection module; A microcontrol unit comprises a voltage collection end, a first control end, a second control end and a third control end. The voltage collection end of the microcontrol unit is electrically connected to the output end of the differential amplifier module, the first control end of the microcontrol unit is electrically connected to the first selection end of the resistance range gating module, the second control end of the microcontrol unit is electrically connected to the second selection end of the resistance range gating module, and the third control end of the microcontrol unit is electrically connected to the third selection end of the resistance range gating module.

2. The motor temperature detection circuit according to claim 1, characterized in that: The current source module includes a first operational amplifier, a second operational amplifier, a voltage source, a first constant current source resistor module, a second constant current source resistor module, a third constant current source resistor module, a fourth constant current source resistor module and a fifth constant current source resistor module, the inverting input terminal of the first operational amplifier is electrically connected to the first end of the first constant current source resistor module and the first end of the second constant current source resistor module, respectively, the voltage source is electrically connected to the first end of the third constant current source resistor module, the in-phase input terminal of the first operational amplifier is electrically connected to the second end of the third constant current source resistor module and the second end of the fourth constant current source resistor module, respectively, the output terminal of the first operational amplifier is electrically connected to the second end of the second constant current source resistor module and the first end of the fifth constant current source resistor module, the in-phase input terminal of the second operational amplifier is electrically connected to the second end of the fifth constant current source resistor module and the current source module, the inverting input terminal of the second operational amplifier is electrically connected to the output terminal of the second operational amplifier and the first end of the fourth constant current source resistor module, and the second end of the first constant current source resistor module is grounded.

3. The motor temperature detection circuit according to claim 1, characterized in that: The temperature sensor module includes a resistance-type temperature sensor and a first regulating resistor module, and the resistance range gating module includes a second regulating resistor module, a third regulating resistor module, a fourth regulating resistor module, a first power switch, a second power switch and a third power switch. The first end of the first regulating resistor module is electrically connected to the current source module, the first end of the second regulating resistor module, the first end of the third regulating resistor module and the first end of the fourth regulating resistor module respectively. The second end of the first regulating resistor module is electrically connected to the first end of the resistance-type temperature sensor, the second end of the second regulating resistor module is electrically connected to the drain of the first power switch, the second end of the third regulating resistor module is electrically connected to the drain of the second power switch, and the second end of the fourth regulating resistor module is electrically connected to the drain of the third power switch. The gate of the first power switch is electrically connected to the first control end of the micro control unit, the gate of the second power switch is electrically connected to the second control end of the micro control unit, and the gate of the third power switch is electrically connected to the third control end of the micro control unit. The source of the first power switch, the source of the second power switch, the source of the third power switch and the second end of the resistance-type temperature sensor are grounded respectively.

4. The motor temperature detection circuit according to claim 3, characterized in that: The differential amplifier module includes a third operational amplifier, a first operational amplifier resistor module, a second operational amplifier resistor module, a third operational amplifier resistor module and a fourth operational amplifier resistor module. The first end of the first operational amplifier resistor module is electrically connected to the first end of the first regulating resistor module. The second end of the first operational amplifier resistor module is electrically connected to the second end of the third operational amplifier resistor module and the in-phase input end of the third operational amplifier, respectively. The inverting input end of the third operational amplifier is electrically connected to the second end of the second operational amplifier resistor module and the first end of the fourth operational amplifier resistor module, respectively. The output ends of the three operational amplifiers are electrically connected to the second end of the fourth operational amplifier resistor module and the voltage collection end of the micro control unit, respectively. The first end of the second operational amplifier resistor module and the first end of the third operational amplifier resistor module are grounded, respectively.

5. The motor temperature detection circuit according to claim 4, characterized in that: The microcontroller unit is used to perform the following steps: When the first power switch is turned on, according to Determining the resistance value of the resistance temperature sensor; When the second power switch is turned on, according to Determining the resistance value of the resistance temperature sensor; When the third power switch is turned on, according to Determining the resistance value of the resistance temperature sensor; Among them, RX is the resistance type temperature sensor, R5 is the fifth constant current source resistor module of the current source module, the second end of the fifth constant current source resistor module is electrically connected to the first end of the first adjustment resistor module, R6 is the first adjustment resistor module, R7 is the second adjustment resistor module, R8 is the third adjustment resistor module, R9 is the fourth adjustment resistor module, R12 is the third op amp resistor module, Vo is the collection voltage, the collection voltage is the voltage collected by the voltage collection end of the micro control unit, and VCC is the voltage source of the current source module.

6. The motor temperature detection circuit according to claim 1, characterized in that: The temperature detection circuit further includes a filter module, which is electrically connected between a voltage collection terminal of the micro control unit and an output terminal of the differential amplifier module.

7. The motor temperature detection circuit according to claim 6, characterized in that: The filter module includes a first filter capacitor module and a filter resistor module, the first end of the filter resistor module is electrically connected to the output end of the differential amplifier module, the second end of the filter resistor module is electrically connected to the second end of the first filter capacitor module and the voltage collection end of the micro control unit respectively, and the first end of the first filter capacitor module is grounded.

8. The motor temperature detection circuit according to claim 1, characterized in that: The temperature detection circuit also includes a second filter capacitor module, a first end of the second filter capacitor module is electrically connected to the conduction end of the resistance range selection module and the input end of the differential amplifier module, and a second end of the second filter capacitor module is grounded.

9. The motor temperature detection circuit according to claim 3, characterized in that: The first power switch, the second power switch and the third power switch are all NMOS.

10. An electronic device, characterized in that: include: A motor temperature detection circuit as claimed in any one of claims 1 to 9.

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