Signal detection circuit, motor protection circuit and vehicle

Abstract

The utility model discloses a signal detection circuit, a motor protection circuit and a vehicle. The signal detection circuit comprises an isolation module and a detection module, the isolation module is used for being connected with a main control chip, performing gating processing on a first detection signal output by the main control chip, and outputting a modulation signal of a target frequency band; and the detection module is connected with the isolation module and is used for processing the modulation signal and outputting a second detection signal. The isolation module in the signal detection circuit plays a gating role on a signal output by the main control chip, only allows a modulation signal which is output by the main control chip, is used for reflecting an abnormal state of a device and has a specific frequency band and amplitude to pass through, and isolates other signals; the influence of interference signals generated in the signal transmission process on the detection result can be avoided, and the false triggering phenomenon is prevented.

Description

Technical Field

[0001] The utility model relates to the technical field of signal detection, in particular to a signal detection circuit, a motor protection circuit and a vehicle. Background Art

[0002] During the process of detecting and controlling device abnormalities, the main control chip or sensor in the signal detection circuit outputs an electrical signal based on the device's normal / abnormal state. The detection unit then detects the electrical signal and determines whether to control the device accordingly. This electrical signal is typically a single-level signal, using high and low levels to distinguish between normal and abnormal states. However, single-level signals have poor noise immunity and often experience distortion or signal jitter due to interference when transmitted over long distances. This can cause the detection unit to misjudge an abnormal state when detecting the electrical signal, ultimately leading to the false triggering of device control actions. Utility Model Content

[0003] The embodiments of the present invention provide a signal detection circuit, a motor protection circuit and a vehicle to solve the problem that the electrical signal transmitted in the existing detection circuit has poor anti-interference performance and is prone to cause errors in the detection results.

[0004] The embodiment of the utility model provides a signal detection circuit, comprising an isolation module and a detection module;

[0005] The isolation module is used to connect to the main control chip, perform gating processing on the first detection signal output by the main control chip, and output a modulated signal of the target frequency band;

[0006] The detection module is connected to the isolation module and is used to process the modulated signal and output a second detection signal.

[0007] Preferably, the detection module includes a rectifier module and a comparator module;

[0008] The rectifier module is connected to the isolation module and is used to rectify the modulated signal to obtain a first voltage signal;

[0009] The comparator module is connected to the rectifier module and is configured to process the first voltage signal and output a second detection signal.

[0010] Preferably, the isolation module includes a first capacitor;

[0011] A first end of the first capacitor is connected to the main control chip, and a second end of the first capacitor is connected to the rectifier module.

[0012] Preferably, the rectifier module includes a first diode, a second diode and a second capacitor;

[0013] The anode of the first diode is connected to the isolation module, and the cathode of the first diode is connected to the comparator module;

[0014] The cathode of the second diode is connected to the connection node between the isolation module and the first diode, and the anode of the second diode is grounded;

[0015] The first end of the second capacitor is connected to the cathode of the first diode, and the second end of the second capacitor is grounded.

[0016] Preferably, the comparator module includes a reference voltage unit and a comparison unit;

[0017] The reference voltage unit is connected to the first end of the comparison unit for outputting a reference voltage signal to the comparison unit;

[0018] The second end of the comparison unit is connected to the rectification module for processing the reference voltage signal and the first voltage signal and outputting a second detection signal.

[0019] Preferably, the reference voltage unit includes a first reference voltage unit and a second reference voltage unit. The first reference voltage unit is used for outputting a first reference voltage signal, and the second reference voltage unit is used for outputting a second reference voltage signal;

[0020] The comparison unit includes a first comparator and a second comparator;

[0021] The non-inverting input terminal of the first comparator is connected to the first reference voltage unit, the inverting input terminal of the first comparator is connected to the rectification module, and the output terminal of the first comparator is connected to the non-inverting input terminal of the first comparator;

[0022] The non-inverting input terminal of the second comparator is connected to the rectification module, the inverting input terminal of the second comparator is connected to the second reference voltage unit, and the output terminal of the second comparator is connected to the non-inverting output terminal of the second comparator;

[0023] The output terminal of the first comparator is connected to the output terminal of the second comparator;

[0024] The comparison unit is used for outputting a second detection signal when the voltage value of the first voltage signal is greater than the second reference voltage signal and less than the first reference voltage signal.

[0025] Preferably, the comparison unit further includes a first feedback resistor and a second feedback resistor;

[0026] Both ends of the first feedback resistor are respectively connected to the non-inverting input terminal and the output terminal of the first comparator;

[0027] Both ends of the second feedback resistor are respectively connected to the non-inverting input terminal and the output terminal of the second comparator.

[0028] An embodiment of the present invention further provides a motor protection circuit, including a main control chip, a drive circuit, and the signal detection circuit described in any one of the above;

[0029] The main control chip is used to connect to the motor and is connected to the signal detection circuit to output a first detection signal to the signal detection circuit according to the motor fault detection state;

[0030] The drive circuit is connected to the signal detection circuit and is used to connect to the motor to control the short circuit of the motor according to a second detection signal.

[0031] Preferably, the drive circuit includes a control tube and a drive chip;

[0032] The first end of the control tube is connected to a voltage source, the second end of the control tube is connected to the signal detection circuit, and the third end of the control tube is grounded;

[0033] The first end of the drive chip is connected to the connection node between the control tube and the voltage source, and the second end of the drive chip is used to connect to the motor. When the control tube is turned on under the control of the second detection signal, it controls the short circuit of the motor.

[0034] An embodiment of the present invention further provides a vehicle, including a motor and the motor protection circuit described in any one of the above.

[0035] In the signal detection circuit, motor protection circuit, and vehicle provided by the embodiments of the present invention, the isolation module in the signal detection circuit functions to select and pass the signal output by the main control chip, and only allows the modulation signal with a specific frequency band and amplitude, which is used to reflect the abnormal state of the device, output by the main control chip to pass through, while isolating other signals, which can avoid the influence of interference signals generated during signal transmission on the detection result and prevent false triggering. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments of the present invention. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0037] Figure 1 It is a schematic block diagram structure of a motor protection circuit in an embodiment of the present invention;

[0038] Figure 2 It is a schematic diagram of a circuit structure of a motor protection circuit in an embodiment of the present utility model.

[0039] In the figure: 1. Isolation module; 2. Detection module; 21. Rectification module; 22. Comparator module; 221. Reference voltage unit; 2211. First reference voltage unit; 2212. Second reference voltage unit; 222. Comparison unit; 3. Main control chip; 4. Drive circuit; 5. Motor. Specific implementation manners

[0040] Next, the technical solutions in the embodiments of the present utility model will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are some, but not all, of the embodiments of the present utility model. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model without making creative efforts shall fall within the protection scope of the present utility model.

[0041] It should be understood that the present utility model can be implemented in different forms and should not be construed as limited to the embodiments presented herein. On the contrary, providing these embodiments will make the disclosure thorough and complete, and will fully convey the scope of the present utility model to those skilled in the art. In the drawings, for clarity, the dimensions and relative dimensions of layers and regions may be exaggerated. The same reference numerals denote the same elements throughout the drawings.

[0042] It should be understood that when an element or layer is referred to as being "on", "adjacent to", "connected to" or "coupled to" another element or layer, it can be directly on, adjacent to, connected or coupled to the other element or layer, or there may be intervening elements or layers. In contrast, when an element is referred to as being "directly on", "directly adjacent to", "directly connected to" or "directly coupled to" another element or layer, there are no intervening elements or layers. It should be understood that although the terms first, second, third, etc. may be used to describe various elements, components, regions, layers and / or parts, these elements, components, regions, layers and / or parts should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or part from another element, component, region, layer or part. Therefore, without departing from the teachings of the present utility model, the first element, component, region, layer or part discussed below may be denoted as the second element, component, region, layer or part.

[0043] Spatial relationship terms such as "under", "below", "beneath", "underneath", "above", "over", etc. may be used herein for convenience of description to describe the relationship of one element or feature shown in the figure with other elements or features. It should be understood that, in addition to the orientation shown in the figure, the spatial relationship terms are also intended to include different orientations of the device in use and operation. For example, if the device in the attached drawing is flipped, then the element or feature described as "under other elements" or "beneath it" or "under it" will be oriented "above" the other elements or features. Therefore, the exemplary terms "under" and "underneath" can include both the upper and lower orientations. The device may be otherwise oriented (rotated 90 degrees or other orientations) and the spatial descriptors used herein are to be interpreted accordingly.

[0044] The purpose of the terms used herein is only to describe specific embodiments and not to limit the present utility model. When used herein, the singular forms of "a", "an" and "the" are also intended to include the plural forms unless the context clearly dictates otherwise. It should also be understood that the terms "comprising" and / or "including", when used in this specification, identify the presence of the stated features, integers, steps, operations, elements and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or groups. When used herein, the term "and / or" includes any and all combinations of the related listed items.

[0045] To thoroughly understand the present utility model, detailed structures and steps will be set forth in the following description in order to explain the technical solutions proposed by the present utility model. The preferred embodiments of the present utility model are described in detail below. However, in addition to these detailed descriptions, the present utility model may also have other embodiments.

[0046] An embodiment of the present utility model provides a signal detection circuit, including an isolation module 1 and a detection module 2; the isolation module 1 is used to connect to a main control chip 3, perform gating processing on a first detection signal output by the main control chip 3, and output a modulation signal of a target frequency band; the detection module 2 is connected to the isolation module 1 and is used to process the modulation signal and output a second detection signal.

[0047] Among them, the main control chip 3 can be used to monitor the anomalies of the device. The first detection signal is the signal output by the main control chip 3 according to the operating conditions of the device to be tested. When the main control chip 3 detects an anomaly in the device to be tested, the first detection signal output is a modulation signal with a specific frequency band and amplitude, such as a PWM signal; when the main control chip 3 detects that the device to be tested has no anomaly, the main control chip 3 outputs other signals different from the modulation signal, such as a DC signal, or other modulation signals with different frequencies or amplitudes from the modulation signal output in the abnormal situation, or the main control chip 3 may also not send a signal to the isolation module 1 when the device to be tested has no anomaly.

[0048] As an example, the signal detection circuit includes an isolation module 1 and a detection module 2. The isolation module 1 is used to be connected to the main control chip 3, receive the first detection signal sent by the main control chip 3, and screen the first detection signal sent by the main control chip 3, only allowing the modulation signal with a specific frequency band and amplitude sent by the main control chip 3 when the device to be tested has an anomaly to pass through, and isolating other signals sent by the main control chip 3. The detection module 2 is connected to the isolation module 1 and is used to process the modulation signal that has passed through the isolation module 1 and output a second detection signal. Specifically, the detection module 2 can output the second detection signal to the drive circuit 4 so that the drive circuit 4 can perform corresponding anomaly handling actions according to the second detection signal.

[0049] In this example, the isolation module 1 plays a gating role for the signal output by the main control chip 3, only allowing the modulation signal with a specific frequency band and amplitude output by the main control chip 3, which is used to reflect the abnormal state of the device, to pass through, while isolating other signals, which can avoid the interference signals generated during signal transmission from affecting the detection result and prevent false triggering phenomena.

[0050] In one embodiment, the detection module 2 includes a rectification module 21 and a comparator module 22; the rectification module 21 is connected to the isolation module 1 and is used to rectify the modulation signal to obtain a first voltage signal; the comparator module 22 is connected to the rectification module 21 and is used to process the first voltage signal and output a second detection signal.

[0051] As an example, the detection module 2 includes a rectification module 21 and a comparator module 22. The rectification module 21 is connected to the isolation module 1 and is used to rectify the modulation signal passing through the isolation module 1 and convert it into a first voltage signal with a single-level property. The comparator module 22 is connected to the rectification module 21 and is used to detect the first voltage signal output by the rectification module 21 to determine whether the first voltage signal is within a preset voltage range. The comparator module 22 is also used to be connected to the drive circuit 4. If the first voltage signal is within the preset voltage range, it outputs a second detection signal to the drive circuit 4 so that the drive circuit 4 can perform a fault emergency stop control on the device according to the second detection signal.

[0052] In one embodiment, the isolation module 1 includes a first capacitor C1; a first end of the first capacitor C1 is connected to the main control chip 3, and a second end of the first capacitor C1 is connected to the rectification module 21.

[0053] As an example, the isolation module 1 includes a first capacitor C1. A first end of the first capacitor C1 is connected to the main control chip 3, and a second end of the first capacitor C1 is connected to the rectification module 21. The parameter setting of the first capacitor C1 should match the target frequency band amplitude of the modulation signal allowed to pass through, such as a PWM signal, so that the first capacitor C1 can only allow the modulation signal of this specific frequency band and amplitude to pass through, while isolating other signals outside this kind of modulation signal, such as DC signals, etc. Utilizing the principle of blocking DC and passing AC of the first capacitor C1 to perform a gating process on the first detection signal output by the main control chip 3 can simplify the circuit structure and reduce the manufacturing cost.

[0054] In one embodiment, the rectification module 21 includes a first diode D1, a second diode D2, and a second capacitor C2; an anode of the first diode D1 is connected to the isolation module 1, and a cathode of the first diode D1 is connected to the comparator module 22; a cathode of the second diode D2 is connected to a connection node between the isolation module 1 and the first diode D1, and an anode of the second diode D2 is grounded; a first end of the second capacitor C2 is connected to the cathode of the first diode D1, and a second end of the second capacitor C2 is grounded.

[0055] As an example, the rectification module 21 includes a first diode D1 and a second diode D2. An anode of the first diode D1 is connected to the isolation module 1, a cathode of the first diode D1 is connected to the comparator module 22, a cathode of the second diode D2 is connected to a connection node between the isolation module 1 and the first diode D1, and an anode of the second diode D2 is grounded. The first diode D1 and the second diode D2 are used to rectify the modulation signal passing through the isolation module 1 into a first voltage signal with a single - level property that can be used for voltage comparison. A first end of the second capacitor C2 is connected to the cathode of the first diode D1, and a second end of the second capacitor C2 is grounded, which is used to filter the first voltage signal to make the output first voltage signal smoother.

[0056] In one embodiment, the comparator module 22 includes a reference voltage unit 221 and a comparison unit 222; the reference voltage unit 221 is connected to a first end of the comparison unit 222 and is used to output a reference voltage signal to the comparison unit 222; a second end of the comparison unit 222 is connected to the rectification module 21, and the comparison unit 222 is used to process the reference voltage signal and the first voltage signal and output a second detection signal.

[0057] As an example, the comparator module 22 includes a reference voltage unit 221 and a comparison unit 222. The reference voltage unit 221 is connected to the first end of the comparison unit 222 and is configured to output a preset reference voltage signal to the comparison unit 222. The second end of the comparison unit 222 is connected to the rectification module 21, and the third end of the comparison unit 222 is configured to be connected to the drive circuit 4. The comparison unit 222 is capable of comparing the reference voltage signal and the first voltage signal and outputting a second detection signal to the drive circuit 4 according to the comparison result.

[0058] In one embodiment, the reference voltage unit 221 includes a first reference voltage unit 2211 and a second reference voltage unit 2212. The first reference voltage unit 2211 is configured to output a first reference voltage signal, and the second reference voltage unit 2212 is configured to output a second reference voltage signal. The comparison unit 222 includes a first comparator L1 and a second comparator L2. The non-inverting input terminal of the first comparator L1 is connected to the first reference voltage unit 2211, the inverting input terminal of the first comparator L1 is connected to the rectification module 21, and the output terminal of the first comparator L1 is connected to the non-inverting input terminal of the first comparator L1. The non-inverting input terminal of the second comparator L2 is connected to the rectification module 21, the inverting input terminal of the second comparator L2 is connected to the second reference voltage unit 2212, and the output terminal of the second comparator L2 is connected to the inverting output terminal of the second comparator L2. The output terminal of the first comparator L1 is connected to the output terminal of the second comparator L2. The comparison unit 222 is configured to output a second detection signal when the first voltage signal is greater than the second reference voltage signal and the first voltage signal is less than the first reference voltage signal.

[0059] As an example, the comparison unit 222 includes a first comparator L1 and a second comparator L2; the reference voltage unit 221 includes a first reference voltage unit 2211 and a second reference voltage unit 2212. The first reference voltage signal is used to generate a first reference voltage signal. The first reference voltage unit 2211 is connected to the non-inverting input terminal of the first comparator L1. The inverting input terminal of the first comparator L1 is connected to the rectification module 21. When the first voltage signal output by the rectification module 21 is less than the first reference voltage signal, the output terminal of the first comparator L1 outputs a high-level signal, that is, the second detection signal. When the first voltage signal output by the rectification module 21 is greater than the first reference voltage signal, the first comparator L1 outputs a low-level signal. The second reference voltage signal is used to generate a second reference voltage signal. The second reference voltage unit 2212 is connected to the inverting input terminal of the second comparator L2. The non-inverting input terminal of the second comparator L2 is connected to the rectification module 21. When the first voltage signal output by the rectification module 21 is greater than the second reference voltage signal, the output terminal of the first comparator L1 outputs a high-level signal, that is, the second detection signal. When the first voltage signal output by the rectification module 21 is less than the second reference voltage signal, the first comparator L1 outputs a low-level signal. At the same time, the output terminal of the first comparator L1 is connected to its own non-inverting input terminal, and the output terminal of the second comparator L2 is also connected to its own non-inverting input terminal, and the output terminals of the first comparator L1 and the second comparator L2 are short-circuited. Therefore, when at least one of the first comparator L1 and the second comparator L2 outputs a low level, the low-level signal will be fed back to the non-inverting input terminals of the first comparator L1 and the second comparator L2, causing both the first comparator L1 and the second comparator L2 to output low-level signals, forming an AND logic, and only when both the first comparator L1 and the second comparator L2 output high-level signals, a high-level signal is output, that is, when the first voltage signal is greater than the second reference voltage signal and less than the first reference voltage signal, the comparison unit 222 outputs a high-level signal, that is, the second detection signal.

[0060] In this example, by setting the first comparator L1, the second comparator L2, the first reference voltage unit 2211, and the second reference voltage unit 2212, the first voltage signal can be detected to determine whether the first voltage signal is within a preset voltage range.

[0061] In an embodiment, the comparison unit 222 further includes a first feedback resistor R1 and a second feedback resistor R2. Two ends of the first feedback resistor R1 are respectively connected to the non-inverting input terminal and the output terminal of the first comparator L1. Two ends of the second feedback resistor R2 are respectively connected to the non-inverting input terminal and the output terminal of the second comparator L2.

[0062] As an example, the comparison unit 222 further includes a first feedback resistor R1 and a second feedback resistor R2. The first feedback resistor R1 is disposed between the non-inverting input terminal and the output terminal of the first comparator L1, and the second feedback resistor R2 is disposed between the non-inverting input terminal and the output terminal of the second comparator L2. The first feedback resistor R1 is disposed on the positive feedback loop of the first comparator L1, and the second feedback resistor R2 is disposed on the positive feedback loop of the second comparator L2, both of which are used to prevent circuit oscillation and improve the stability of the circuit.

[0063] The embodiment of the present utility model further provides a motor protection circuit, including a main control chip 3, a driving circuit 4, and the signal detection circuit in the above embodiment; the main control chip 3 is used to connect to the motor 5 and is connected to the signal detection circuit to output a first detection signal to the signal detection circuit according to the fault detection state of the motor 5; the driving circuit 4 is connected to the signal detection circuit and is used to connect to the motor 5 to control the short circuit of the motor 5 according to the second detection signal.

[0064] As an example, the motor protection circuit includes a main control chip 3, a driving circuit 4, and the signal detection circuit in the above example. The main control chip 3 is connected to the motor 5, specifically, it can be connected to the detection element disposed in the motor 5. Through the detection element, it can be detected whether the motor 5 is in a fault state, and it can be judged whether the motor 5 needs to perform ASC (active short circuit) currently. The main control chip 3 is also connected to the signal detection circuit. When the motor 5 is in a fault state and needs to perform ASC, the main control chip 3 outputs a modulation signal with a specific frequency band and amplitude, such as a PWM signal, to the signal detection circuit. When the motor 5 is not in a fault state or does not need to perform ASC, the main control chip 3 outputs other signals other than the modulation signal with a specific frequency band and amplitude to the signal detection circuit, or does not output a signal. The signal detection circuit is also connected to the driving circuit 4 and is used to detect and process the first detection signal output by the main control chip 3. When it detects that the main control chip 3 outputs a modulation signal with a specific frequency band and amplitude, it will output a second detection signal to the driving circuit 4. The driving circuit 4 controls the short circuit of the motor 5 according to the second detection signal to complete the active short circuit operation.

[0065] In this example, the signal detection circuit in the motor protection circuit can function as a gating for the first detection signal output by the main control chip 3, allowing only the modulation signal with a specific frequency band and amplitude output by the main control chip 3 to pass through, while isolating other signals, which can avoid the influence of interference signals generated during signal transmission on the detection result and prevent the occurrence of active short circuit mis-trigger phenomena.

[0066] In one embodiment, the drive circuit 4 includes a control transistor S1 and a drive chip U1; a first end of the control transistor S1 is connected to a voltage source VCC, a second end of the control transistor S1 is connected to a signal detection circuit, and a third end of the control transistor S1 is grounded; a first end of the drive chip U1 is connected to a connection node between the control transistor S1 and the voltage source VCC, and a second end of the drive chip U1 is used to connect to the motor 5. When the control transistor S1 is turned on under the control of the second detection signal, the motor 5 is controlled to be short-circuited.

[0067] As an example, the drive circuit 4 includes a control transistor S1 and a driver chip U1. The control transistor S1 can be an NPN-type MOS transistor, wherein the first end of the control transistor S1 serves as the drain electrode of the MOS transistor, the second end of the control transistor S1 serves as the gate electrode of the MOS transistor, and the third end of the control transistor S1 serves as the source electrode of the MOS transistor. The first end of the control transistor S1 is connected to the voltage source VCC, the second end of the control transistor S1 is connected to the signal detection circuit, and the third end of the control transistor S1 is grounded. The first end of the driver chip U1 is connected to the connection node between the control transistor S1 and the voltage source VCC, and the second end of the driver chip U1 is connected to the motor 5. When the second detection signal is input to the second end of the control transistor S1, the control transistor S1 is turned on. When the control transistor S1 is turned on, the first end of the driver chip U1 is converted from a high level to a low level, and the second end of the driver chip U1 outputs a control signal to the motor 5, causing the motor 5 to short-circuit.

[0068] An embodiment of the present utility model further provides a vehicle, comprising a motor 5 and the motor protection circuit in the above embodiment.

[0069] As an example, the vehicle includes a motor 5 and the motor protection circuit in the above example. The signal detection circuit in the motor protection circuit can play a gating role on the signal output by the main control chip 3, allowing only the modulated signal with a specific frequency band and amplitude output by the main control chip 3 to pass through, while isolating other signals, and can avoid the interference signal generated during the signal transmission process from affecting the detection result. When the motor protection circuit is connected to the motor 5, it can accurately transmit the control signal to the motor 5, and prevent the active short circuit false triggering phenomenon when the motor 5 does not need to be actively short-circuited. When the motor protection circuit and the motor 5 are used in the vehicle, they can eliminate the active short circuit false triggering phenomenon of the motor 5 caused by interference, so that the active short circuit can be performed normally and reliably, and the safety of the vehicle and passengers can be guaranteed as much as possible.

[0070] The above-described embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the various embodiments of the present invention, and should all be included within the protection scope of the present invention.

Claims

1. A signal detection circuit, characterized in that, It includes an isolation module and a detection module; The isolation module is used to connect to the main control chip, perform gating processing on the first detection signal output by the main control chip, and output a modulation signal in a target frequency band; The detection module is connected to the isolation module and is used to process the modulation signal and output a second detection signal.

2. The signal detection circuit according to claim 1, wherein The detection module includes a rectification module and a comparator module; The rectification module is connected to the isolation module and is used to rectify the modulation signal to obtain a first voltage signal; The comparator module is connected to the rectification module and is used to process the first voltage signal and output a second detection signal.

3. The signal detection circuit according to claim 2, wherein The isolation module includes a first capacitor; The first end of the first capacitor is connected to the main control chip, and the second end of the first capacitor is connected to the rectification module.

4. The signal detection circuit according to claim 2, wherein The rectification module includes a first diode, a second diode, and a second capacitor; The anode of the first diode is connected to the isolation module, and the cathode of the first diode is connected to the comparator module; The cathode of the second diode is connected to the connection node between the isolation module and the first diode, and the anode of the second diode is grounded; The first end of the second capacitor is connected to the cathode of the first diode, and the second end of the second capacitor is grounded.

5. The signal detection circuit according to claim 2, wherein The comparator module includes a reference voltage unit and a comparison unit; The reference voltage unit is connected to the first end of the comparison unit and is used to output a reference voltage signal to the comparison unit; The second end of the comparison unit is connected to the rectification module and is used to process the reference voltage signal and the first voltage signal and output a second detection signal.

6. The signal detection circuit according to claim 5, wherein The reference voltage unit includes a first reference voltage unit and a second reference voltage unit. The first reference voltage unit is used to output a first reference voltage signal, and the second reference voltage unit is used to output a second reference voltage signal; The comparison unit includes a first comparator and a second comparator; The non-inverting input terminal of the first comparator is connected to the first reference voltage unit, the inverting input terminal of the first comparator is connected to the rectification module, and the output terminal of the first comparator is connected to the non-inverting input terminal of the first comparator; The non-inverting input terminal of the second comparator is connected to the rectification module, the inverting input terminal of the second comparator is connected to the second reference voltage unit, and the output terminal of the second comparator is connected to the non-inverting output terminal of the second comparator; The output terminal of the first comparator is connected to the output terminal of the second comparator; The comparison unit is used to output a second detection signal when the voltage value of the first voltage signal is greater than the second reference voltage signal and less than the first reference voltage signal.

7. The signal detection circuit according to claim 6, wherein The comparison unit further includes a first feedback resistor and a second feedback resistor; Both ends of the first feedback resistor are respectively connected to the non-inverting input terminal and the output terminal of the first comparator; Both ends of the second feedback resistor are respectively connected to the non-inverting input terminal and the output terminal of the second comparator.

8. A motor protection circuit, characterized in that, It includes a main control chip, a drive circuit, and the signal detection circuit according to any one of claims 1-7; The main control chip is used to connect to the motor and is connected to the signal detection circuit to output a first detection signal to the signal detection circuit according to the motor fault detection status; The drive circuit is connected to the signal detection circuit and is used to connect to the motor to control the short circuit of the motor according to the second detection signal.

9. The motor protection circuit according to claim 8, wherein The drive circuit includes a control tube and a drive chip; The first end of the control tube is connected to the voltage source, the second end of the control tube is connected to the signal detection circuit, and the third end of the control tube is grounded; The first end of the drive chip is connected to the connection node between the control tube and the voltage source, and the second end of the drive chip is used to connect to the motor. When the control tube is turned on under the control of the second detection signal, it controls the short circuit of the motor.

10. A vehicle, characterized in that, It includes a motor and the motor protection circuit according to any one of claims 8-9.

Images