Driving circuit fault detection system

Abstract

The invention relates to a driving circuit fault detection system and method, a vehicle-mounted buzzer control device and a vehicle. The driving circuit fault detection system comprises a first switch module which comprises a first transistor, the base electrode of the first transistor receives control signal input, and the collector electrode of the first transistor outputs a first switch signal; the second switch module comprises a second transistor, the base electrode of the second transistor receives the first switch signal, the emitter electrode of the second transistor receives the input of the power supply voltage end, and the collector electrode of the second transistor is connected to the tested device; and the detection module is connected to the collector of the second transistor and converts a level signal of the second transistor into a direct-current level, and the value of the direct-current level is used for determining the fault type of the detected device.

Description

Technical Field

[0001] The present disclosure relates to the field of detection, and in particular to a drive circuit fault detection system and method, a vehicle-mounted buzzer control device and a vehicle. Background Art

[0002] Some loads (such as vehicle-mounted equipment) need to be driven or powered by high or low levels or square waves (such as PWM signals, etc.). For such loads, how to detect faults in the load power supply circuit based on high or low level drive signals becomes a challenge. For example, for a vehicle-mounted buzzer, it uses a periodic signal with a certain frequency (such as PWM signal, etc.) for power supply to make it emit a periodic buzzing sound. It is necessary to determine the circuit faults of such devices, such as short circuit, open circuit, and abnormal frequency of periodic signals. Summary of the invention

[0003] In view of the above problems, the present disclosure aims to provide a drive circuit fault detection system and method, a vehicle-mounted buzzer control device and a vehicle.

[0004] The first aspect of the present disclosure is a drive circuit fault detection system, comprising: a first switch module, which includes a first transistor, the base of which receives a control signal input, and the collector of which outputs a first switch signal; a second switch module, which includes a second transistor, the base of which receives the first switch signal, the emitter of which receives an input from a power supply voltage terminal, and the collector of which is connected to a device under test; and a detection module, which is connected to the collector of the second transistor and converts its level signal into a DC level, and the value of the DC level is used to determine the fault type of the device under test.

[0005] According to the drive circuit fault detection system of some embodiments of the present disclosure, optionally, the second switch module also includes a third transistor, the collector of the third transistor is connected to the base of the second transistor, the base of the third transistor is connected to the emitter of the second transistor and the base of the second transistor, and the emitter of the second transistor and the emitter of the third transistor receive the input of the power supply voltage terminal.

[0006] According to the drive circuit fault detection system of some embodiments of the present disclosure, optionally, the first switch module also includes a first resistor, the first resistor is connected between the collector of the first transistor and a first connection point, and the first connection point is connected to the base of the second transistor and the collector of the third transistor.

[0007] According to the drive circuit fault detection system of some embodiments of the present disclosure, optionally, the second switch module also includes a second resistor, the second resistor is connected between a second connection point and a third connection point, the second connection point connects the base of the third transistor and the emitter of the second transistor, and the third connection point connects the emitter of the third transistor and the power supply voltage terminal.

[0008] According to the drive circuit fault detection system of some embodiments of the present disclosure, optionally, the resistance value of the second resistor is determined according to the base-emitter voltage of the third transistor and the rated current of the device under test.

[0009] According to the drive circuit fault detection system of some embodiments of the present disclosure, optionally, the second transistor and the third transistor are both PNP transistors.

[0010] According to the drive circuit fault detection system of some embodiments of the present disclosure, optionally, the second switch module also includes a third resistor, and the base of the third transistor is connected to the base of the second transistor via the third resistor.

[0011] According to the drive circuit fault detection system of some embodiments of the present disclosure, optionally, the second switch module also includes a first capacitor, and the first capacitor is connected between the base of the third transistor and the base of the second transistor.

[0012] According to some embodiments of the drive circuit fault detection system of the present disclosure, optionally, the detection module also includes a second capacitor and a fourth resistor, the first end of the fourth resistor is connected to the collector of the second transistor and the second end is connected to the output terminal that outputs the DC level, the first end of the second capacitor is connected to the output terminal that outputs the DC level and the second end is grounded.

[0013] According to the drive circuit fault detection system of some embodiments of the present disclosure, optionally, the detection module further includes a fifth resistor, a first end of the fifth resistor is connected to the output end that outputs the DC level and a second end is grounded.

[0014] According to the drive circuit fault detection system of some embodiments of the present disclosure, optionally, the drive circuit fault detection system also includes a bidirectional electrostatic discharge protection diode, one end of the bidirectional electrostatic discharge protection diode is connected to the collector of the second transistor and the other end is grounded.

[0015] According to the drive circuit fault detection system of some embodiments of the present disclosure, optionally, the drive circuit fault detection system also includes a Schottky diode, one end of the Schottky diode is connected to the collector of the second transistor and the other end is grounded.

[0016] According to the drive circuit fault detection system of some embodiments of the present disclosure, optionally, the drive circuit fault detection system further includes a third capacitor, one end of the third capacitor is connected to the control signal input and the other end is grounded.

[0017] According to the drive circuit fault detection system of some embodiments of the present disclosure, optionally, the drive circuit fault detection system further includes a filter capacitor group, wherein one end of the capacitor of the filter capacitor group is connected to the power supply voltage end and the other end is grounded.

[0018] According to some embodiments of the drive circuit fault detection system of the present disclosure, optionally, the value of the DC level is used to determine the fault type of the device under test, further including determining the fault type of the device under test based on comparison of the value of the DC level with a predetermined fault level range value.

[0019] According to the drive circuit fault detection system of some embodiments of the present disclosure, optionally, the DC level is used to determine a fault regarding the frequency of the voltage signal at the collector of the second transistor.

[0020] The second aspect of the present disclosure provides a driving circuit fault detection method, which is used in a driving circuit fault detection system of any of the aforementioned embodiments, and includes the following steps: in response to the value of the DC level being within a first predetermined fault range value, determining that the circuit under test has an open circuit fault; in response to the value of the DC level being within a second predetermined fault range value, determining that the circuit under test has a short circuit to power supply or a short circuit to ground; and determining the frequency of the voltage signal at the collector of the second transistor based on the DC level, and determining a driving frequency fault of the device under test based on the frequency.

[0021] A vehicle-mounted buzzer control device according to a third aspect of the present disclosure includes a drive circuit fault detection system according to any of the aforementioned embodiments.

[0022] The vehicle of the fourth aspect of the present disclosure includes the vehicle-mounted buzzer control device according to any of the foregoing embodiments, or includes the drive circuit fault detection system according to any of the foregoing embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 is a module diagram of a drive circuit fault detection system 100 according to some embodiments of the present disclosure.

[0024] Figure 2 is a module diagram of a drive circuit fault detection system 200 according to other embodiments of the present disclosure.

[0025] Figure 3 is a flowchart of a drive circuit fault detection method 300 according to some embodiments of the present disclosure. DETAILED DESCRIPTION

[0026] The following describes some of the various embodiments of the present disclosure, which are intended to provide a basic understanding of the present disclosure, but are not intended to identify the key or decisive elements of the present disclosure or to limit the scope of protection.

[0027] For brevity and illustrative purposes, the principles of the present disclosure are described herein mainly with reference to its exemplary embodiments. However, those skilled in the art will readily recognize that the same principles are equally applicable to and can be implemented in all types of drive circuit fault detection systems and methods, vehicle-mounted buzzer control devices and vehicles, and any such changes do not depart from the true spirit and scope of the present patent application.

[0028] Moreover, in the following description, reference is made to the accompanying drawings, which illustrate specific exemplary embodiments. Electrical, mechanical, logical and structural changes may be made to these embodiments without departing from the spirit and scope of the present disclosure. In addition, although the features of the present disclosure are disclosed in conjunction with only one of several implementations / embodiments, this feature may be combined with one or more other features of other implementations / embodiments as may be desired and / or advantageous for any given or identifiable function. Therefore, the following description should not be regarded as limiting, and the scope of the present disclosure is defined by the appended claims and their equivalents.

[0029] Terms such as “having” and “including” indicate that in addition to the units (modules) and steps directly and explicitly stated in the specification and claims, the technical solution of the present disclosure does not exclude the situation where it has other units (modules) and steps that are not directly or explicitly stated.

[0030] In this article, "device under test" refers to a device or equipment powered by a certain working voltage. In particular, it can include a device driven by a high-frequency square wave, such as a car buzzer, which inputs alternating high and low levels (square waves) to continuously turn on and off to form an effect corresponding to the square wave frequency (such as emitting a buzzing sound of a certain frequency).

[0031] Figure 1is a module diagram of a drive circuit fault detection system 100 according to some embodiments of the present disclosure. The drive circuit fault detection system 100 may include a first switch module 110, a second switch module 120 and a detection module 130. The first switch module 110 may include a first transistor, whose base receives a control signal input (that is, the input of the first switch module 110, such as the control signal from the main control unit MCU shown in the figure), and whose collector outputs a first switch signal (that is, the output of the first switch module 110). The second switch module 120 may include a second transistor, whose base receives the first switch signal (the first switch signal serves as the input of the second switch module 120), the emitter receives an input of a power supply voltage terminal Vb (the power supply voltage serves as another input of the second switch module 120), and the collector of the second transistor (serves as the output of the second switch module 120, such as Figure 1 The detection module 130 is connected to the collector C2 of the second transistor (that is, the output terminal of the second switch module 120) and converts its level signal (as the input level of the device under test) into a DC level (output via the P4 terminal), and the value of the DC level can be used to determine the fault type of the device under test.

[0032] In some examples, for example, the input end of the first switch module 110 can receive a PWM control signal input from a controller (e.g., a microcontroller unit MCU). The first transistor, as a switching element, can decide whether to turn on or off the entire circuit according to the state of the PWM signal. For example, when the first transistor is an NPN transistor, the PWM signal is high and the first transistor is turned on, allowing current to flow; conversely, when the PWM signal is low, the first transistor is turned off, interrupting the current path. For example, in some scenarios, the MCU sends a periodic PWM signal (e.g., a frequency of 3.8kHz and a duty cycle of 50%), and the first transistor will be periodically turned on and off according to this PWM signal, thereby achieving overall switch control of the subsequent circuit by outputting the first switch signal.

[0033] The second switch module 120 includes a second transistor, whose base receives the first switch signal from the first switch module 110, the emitter receives the input of the power supply voltage terminal, and the collector C2 is connected to the device under test RL (such as a car buzzer), so that the on and off of the second transistor is controlled by the first switch signal, thereby controlling the on and off of the power supply to the device under test. For example, in some scenarios, when the first transistor is turned on, the second transistor is also turned on, and the current flows from the positive electrode of the power supply through the second transistor to the device under test RL.

[0034] The detection module 130 is connected to the collector of the second transistor and converts its level signal into a DC level. The detection module 130 can be any circuit structure that converts high and low level signals (such as the level signal generated by the output change generated by the collector of the second transistor when the first switch signal is input to its base) into a smooth DC level, and the present disclosure is not limited to this. As an example, the detection module 130 can be composed of an RC resistor-capacitor circuit, which is used to convert the rapidly changing high and low level signals (such as the square wave level signal corresponding to the input PWM control signal) into a relatively stable DC level, and the MCU can judge the working state of the device under test based on this DC level value, and identify whether there are open circuits, short circuits or abnormal frequencies. For example, assuming that the device under test should work at a predetermined frequency (corresponding to the high and low level changes of the collector output of the second transistor), if the actually measured DC level deviates from the expected value, it indicates that the device under test may have an open circuit or short circuit fault. Among them, for example, if the DC level is low, there may be an open circuit fault; if the DC level is too low, it may be that the device under test is short-circuited to the ground. In this way, the MCU can monitor the working state of the device under test in real time, and promptly discover and report circuit fault problems.

[0035] Figure 2 is a schematic diagram of a module of a drive circuit fault detection system 200 according to other embodiments of the present disclosure. Figure 1 Similarly, the drive circuit fault detection system 200 may include a first switch module 210, a second switch module 220 and a detection module 230. The first switch module 210 may include a first transistor 212, whose base B1 receives a control signal input (that is, an input of the first switch module 210, for example Figure 2 The first switch signal is output from the collector C1 (that is, the output of the first switch module 210). The second switch module 220 may include a second transistor 222, whose base B2 receives the first switch signal (the first switch signal is used as the input of the second switch module 220), and the emitter E2 receives the input of the power supply voltage terminal Vb (the power supply voltage is used as another input of the second switch module 220), and the collector C2 of the second transistor 222 (as the output of the second switch module 220) is connected to the device under test (shown as RL). The detection module 230 is connected to the collector C2 of the second transistor 222 (that is, the output of the second switch module 220) and converts its level signal (as the input level of the device under test RL) into a DC level, and the value of the DC level can be used to determine the fault type of the device under test RL, for example, the MCU collects the value of the DC level through the level collection terminal MCU_AI (shown as P4) and performs fault judgment.

[0036] In addition, the second switch module 220 further includes a third transistor 223, the collector C3 of the third transistor 223 is connected to the base B2 of the second transistor 222, the base B3 of the third transistor 223 is connected to the emitter E2 of the second transistor 222 and the base B2 of the second transistor 222, and the emitter E2 of the second transistor 222 and the emitter E3 of the third transistor 223 receive the input of the power supply voltage terminal Vb. Under this structure, the base voltages of the third transistor 223 and the second transistor 222 are close to or equal. Take the second transistor 222 and the third transistor 223 as PNP transistors and the first transistor as NPN transistor as an example. When the input of the first switch module 210 is a high level signal, the first transistor 212 is turned on, so that the voltage of the collector C1 of the first transistor 212 drops from close to the power supply voltage Vb to substantially 0V. The base B2 voltage of the second transistor 222 is thus also substantially 0V, the second transistor 222 is turned on, and the device under test RL is powered and works at a voltage close to the power supply voltage Vb. When the input of the first switch module 210 is a low level signal, the first transistor 212 is turned off, so that the voltage of the collector C1 of the first transistor 212 rises from substantially 0V to close to the power supply voltage Vb. At this time, the voltage of the base B2 of the second transistor 222 is equal to or approximately equal to the emitter E2 of the second transistor 222. The second transistor 222 is turned off, and the power supply of the device under test changes from close to the power supply voltage Vb to close to 0V, so it no longer works. Therefore, by alternating the high and low levels of the input of the first switch module 210, the alternating conduction and cutoff of each transistor can be achieved, thereby achieving the device under test to work at a certain frequency, for example, a car buzzer is powered at a certain frequency and emits a buzzing sound corresponding to the frequency.

[0037] Continue to refer Figure 2 In some embodiments, the first switch module 210 further includes a first resistor 214, which is connected between the collector C1 of the first transistor 212 and the first connection point P1 between the base B2 of the second transistor 212 and the collector C3 of the third transistor 223. The existence of the first resistor 214 can play a role in current limiting protection for the first transistor 212 and the second transistor 222, so as to protect the first transistor 212 and the second transistor 222 from / mitigation of damage caused by excessive current and voltage when, for example, the power supply voltage is short-circuited (for example, the original 12V voltage is short-circuited to 48V voltage or a higher transient surge voltage pulse is injected into the power supply, etc.).

[0038] Continue to refer Figure 2In some embodiments, the second switch module 220 further includes a second resistor 224, the second resistor 224 is connected between the second connection point P2 and the third connection point P3, the third connection point P3 is connected to the power supply voltage terminal Vb and the emitter E3 of the third transistor 223, and the second connection point P2 is connected to the base B3 of the third transistor 223 and the emitter E2 of the second transistor 222. The second resistor 224 can protect the device under test (load RL) from / mitigate damage caused by excessive current and voltage, such as the excessive current and voltage caused by the short circuit fault from the 12V power supply described above.

[0039] Continue to refer Figure 2 In some embodiments, the resistance of the second resistor 224 is determined according to the base-emitter voltage of the third transistor 223 and the rated current of the device under test. The resistance of the second resistor 224 can be determined according to the rated operating current (rated voltage / rated internal resistance) of the device under test. For example, the resistance of the second resistor 224 can be equal to the base-emitter conduction voltage V of the third transistor 223. B3E3 In this way, the second resistor 224 can be accurately selected and adjusted according to the device under test RL.

[0040] Continue to refer Figure 2 In some embodiments, the second transistor 222 and the third transistor 223 are both PNP transistors. On this basis, the current Ic1 of the collector C2 of the second transistor 222 flows through the second resistor 224, so that the base-emitter conduction voltage V B3E3 The value of is fixed. Figure 2 , the base E2 of the second transistor 222 and the base E3 of the third transistor 223 can be connected to each other. For the second transistor 222, its base emitter voltage V B2E2 Equal to or approximately equal to V B3E3 At this time, if the second transistor 222 and the third transistor 223 have the same specifications, the current Ic2 flowing through the collector C3 of the third transistor 223 is equal to Ic1, that is, Ic1=Ic2=V B3E3 / R 224 , R 224 is the resistance value of the second resistor 224. In this way, the two constitute a dual PNP type constant current source structure, and the third transistor 223 can cooperate with the second resistor 224 to provide a stable rated working current output to the device under test and play a role in current limiting.

[0041] Continue to refer Figure 2In some embodiments, the second switch module 200 further includes a third resistor 226, and the base B3 of the third transistor 223 is connected to the base B2 of the second transistor 222 via the third resistor 226. The third resistor 226 makes the voltage of the base B3 of the third transistor 223 and the base B2 of the second transistor 222 substantially the same, and makes the voltage of the emitter E2 of the second transistor 222 and the base B2 of the second transistor 222 substantially the same. The third resistor 226 can ensure that the second transistor 222 is turned off when the input control signal PWM is at a low level. In addition, when the circuit does not have an input control signal (such as a PWM signal) or the entire detection system is not working, the third resistor 226 can prevent the second transistor 222 and the third transistor 223 from being mis-conducted.

[0042] Continue to refer Figure 2 In some embodiments, the second switch module 220 further includes a first capacitor 228, and the first capacitor 228 is connected between the base B3 of the third transistor 223 and the base B2 of the second transistor 222. In this way, the second transistor 222 and the third transistor 223 can be prevented from switching on too fast (i.e., the time from cutoff to on is too short) when being turned on, and the high-frequency filtering function is played to improve the electromagnetic compatibility (EMC) problem of the detection system.

[0043] Continue to refer Figure 2 In some embodiments, the detection module 230 may further include a second capacitor 232 and a fourth resistor 234, wherein the first end of the fourth resistor 234 is connected to the collector C2 of the second transistor 222 and the second end is connected to the output end (shown as P4) of the DC level, and the first end of the second capacitor 232 is connected to the output end P4 of the DC level and the second end is grounded GND. The second capacitor 232 and the fourth resistor 234 thus form an RC resistor-capacitor circuit, and the RC resistor-capacitor circuit averages the pulse voltage, so that the high and low level signals from the collector C2 of the second transistor 222 (for example, the signal generated at the collector C2 of the second transistor 222 due to the PWM input of the control signal of the first switch module 210 by the MCU) can be converted into a smooth and stable DC level, and the high frequency components in the original high and low level signals are filtered out, leaving a relatively stable DC level component, so as to be output from the output end P4 of the DC level for detection. In addition, it also avoids directly transmitting the high-speed switching signal to sensitive components (such as MCU) that may not tolerate such signals, thereby reducing the potential risk of damage.

[0044] Continue to refer Figure 2In some embodiments, the detection module 230 further includes a fifth resistor 236, the first end of which is connected to the output terminal P4 of the DC level and the second end is grounded GND. In this way, the fifth resistor 236 can form a voltage divider circuit with the fourth resistor 234, and when the high and low level signals are converted into DC level signals, the amplitude of the DC level signal is adjusted in proportion (corresponding to the voltage divider ratio of the voltage divider circuit), so that the range limit of the output terminal P4 of the DC level is met when the detection voltage of the output terminal P4 of the DC level is limited (for example, the acquisition voltage of some MCUs is low, which is 0-5V). For example, if the load voltage (the collector C2 voltage of the second transistor 222) is high, and the input pin (i.e., P4) of the MCU can only accept a voltage within a limited range (for example, 3.3V or 5V), then by adjusting the ratio of the fifth resistor 236 to the fourth resistor 234, it can be ensured that the voltage provided to the MCU is within its safe operating range.

[0045] Continue to refer Figure 2 In some embodiments, the drive circuit fault detection system 200 also includes a bidirectional electrostatic discharge (ESD) protection diode 240, one end of which is connected to the collector C2 of the second transistor 222 and the other end is grounded GND. The bidirectional ESD protection diode 240 can be turned on when voltage is applied in the forward and reverse directions, thereby providing effective protection against transient high voltages. When external static electricity or transient high-voltage shocks reach the collector C2 of the second transistor 222, the bidirectional ESD protection diode 240 can respond quickly and turn on, safely directing excess energy to the ground line to prevent these transient voltages from damaging the transistor and its connected circuits. In this way, the entire detection system not only enhances the ability to resist sudden electrostatic events, but also improves the reliability and stability of the system, and reduces the risk of failures caused by ESD.

[0046] Continue to refer Figure 2 In some embodiments, the drive circuit fault detection system 200 further includes a Schottky diode 250, one end of which is connected to the collector C2 of the second transistor 222 and the other end is grounded GND. When an abnormally high voltage peak occurs, the Schottky diode 250 can be quickly turned on to shunt the current to the ground, thereby protecting the subsequent circuit from overvoltage. This configuration not only improves the anti-interference capability of the system, but also, due to the fast response characteristics of the Schottky diode, it can effectively suppress switching noise, improve EMC performance, and reduce potential electromagnetic radiation problems. In addition, for some inductive loads (such as buzzers), there are relatively large inductance devices inside. When the inductive load works normally, the internal inductance device stores potential energy or current, so the Schottky diode 250 can discharge the electromotive force or current stored inside the inductive load.

[0047] Continue to refer Figure 2 In some embodiments, the drive circuit fault detection system 200 also includes a third capacitor 260, one end of the third capacitor 260 is connected to the control signal input and the other end is grounded GND. The third capacitor 260 is mainly used for decoupling and filtering, especially for the input path of the control signal. When the control signal is provided to the first switch module 210, it may be accompanied by high-frequency noise or transient fluctuations. The third capacitor 260, as a bypass capacitor, can provide a low-impedance path between the power supply and the ground, so that these high-frequency components can be directly shorted to the ground without affecting the quality of the control signal. This helps to maintain the purity of the control signal, ensure its stability and accuracy, while reducing electromagnetic interference to the external environment and improving the overall EMC performance of the system. In addition, it can also help maintain the voltage stability of the control signal source, especially when the load changes greatly.

[0048] Continue to refer Figure 2 In some embodiments, the drive circuit fault detection system 200 further includes a filter capacitor group 270 (e.g., 270-1 and 270-2 shown in the figure, but it can be understood that it is not limited to 2), one end of the capacitor of the filter capacitor group 270 is connected to the power supply voltage terminal Vb and the other end is grounded GND. The filter capacitor group 270 is usually composed of a plurality of capacitors of different capacities, which is intended to smooth the power supply voltage and remove the AC component and other unwanted frequency components therein. Before the power supply voltage enters the drive circuit, the filter capacitor group 270 will first process the power supply voltage signal, absorb the ripple and noise on the power line, and provide a cleaner and more stable DC voltage for the subsequent circuit. In some examples, the filter capacitor group 270 is two capacitors (e.g., 270-1 and 270-2), which are respectively used for filtering high-frequency power supply voltage signals and low-frequency power supply voltage signals. In this way, the stability and reliability of the system can be improved, the electromagnetic interference from the power supply can be reduced, and the EMC characteristics of the system can be optimized.

[0049] In terms of fault detection, the value of the DC level (P4) can be used to determine the fault type of the device under test, which can further include determining the fault type of the device under test based on the comparison of the DC level value with the predetermined fault level range value. It can be understood that after passing through the detection module 230, the high and low levels output from C2 are processed into relatively smooth DC levels, and the output frequencies of the high and low levels output by C2 can reflect whether the load RL and the drive circuit (210 and 230) connected to the load RL have open circuits, short circuits (short circuits to the power supply and short circuits to the ground) and other faults, and the output frequencies of the high and low levels can be reflected as DC level values ​​after smoothing. Therefore, the type of fault in the circuit can be determined based on the DC level value.

[0050] Specifically, the time constant of the RC resistor-capacitor circuit composed of the resistor 234 and the capacitor 232 can be set to τ=R*C, where R is the resistance value of the resistor 234 (ohm Ω), C is the capacitance value of the capacitor 232 (farad F), and the average voltage Vavg of the high and low levels output at C2=D*Vc2, where D is the duty cycle of the high and low level signals (for example, 50%). Based on these premises, the output voltage (DC level value) of the P4 point of the RC circuit composed of the resistor 234 and the capacitor 232 is Vout≈Vavg*(1-e -t / τ ). Therefore, under steady-state conditions (i.e., when the time is long enough, such as after several time constants), the output voltage Vout is close to the average voltage Vavg. Therefore, in the drive circuit and the load, different circuit faults correspond to different load input voltages (i.e. Figure 2 For example, when there is an open circuit in the circuit, the voltage range at C2 is s1, and when there is a short circuit to ground in the circuit, the voltage range at C2 is s2 (a short circuit to ground is generally close to 0V, for example, s2 is 0-0.8V), and so on. These voltage ranges s1 and s2 can be mapped to different voltage values ​​at point P4. Therefore, it is possible to determine in which voltage range the voltage at C2 is through the real-time measurement value of Vout, and thus determine the corresponding circuit fault.

[0051] Furthermore, additionally or alternatively, the DC level can also be used to determine a fault with respect to the frequency of the voltage signal at the collector of the second transistor. For certain loads RL that require a certain frequency for power supply and driving, the frequency of the high and low levels output from C2 can be detected. This is because the DC level values ​​of the high and low levels of different frequencies are correspondingly different after being smoothed. Specifically, according to the formula Vout(t)≈Vavg*(1-e -t / τ ) It can be seen that the Vout value read by the MCU is known, the time constant τ=R*C is also known, and Vavg=D*Vc2 is also known, so the value of t can be obtained, and t=1 / f, so the frequency f of the high and low levels output by C2 can be determined. By comparing the frequency f with the ideal driving voltage frequency of the device under test, it can be checked whether there is a voltage frequency fault.

[0052] Therefore, the present disclosure may also include a method for detecting a driving circuit fault, which may, for example, include the following steps: in response to the value of the DC level being within a first predetermined fault range value, determining that the circuit under test has an open circuit fault; in response to the value of the DC level being within a second predetermined fault range value, determining that the circuit under test has a short circuit to power supply or a short circuit to ground; and determining the frequency of the voltage signal at the collector of the second transistor based on the DC level, and determining a driving frequency fault of the device under test based on the frequency.

[0053] Figure 3 300 is a flow chart of a drive circuit fault detection method 300 according to some embodiments of the present disclosure. The method 300 can be directly executed in an MCU for determining the fault type according to the DC level value at P4, for example. First, the process of the method is started at 302, and in 304, the DC level value is read by the MCU. Then, in box 306, it is determined whether the DC level value is within the interval 1 indicating that the circuit (load RL and its drive circuit) does not have a fault. If it is (Y), it enters 308 and determines that the DC level value is normal, and the process ends directly at 324. If it is not (N), it enters box 310 and determines that the DC level value is abnormal. Then, after 310, in box 312, it continues to determine whether the DC level value is in the interval 2 indicating that the circuit has an open circuit fault. If it is (Y), it enters 314 and determines that the circuit has an open circuit fault, and then the process ends directly at 324. If it is not (N), it enters box 316 and determines that the DC level value is abnormal. Then, after 316, it is further determined in box 318 whether the DC level value is in interval 3 indicating that the circuit has a short circuit fault. If it is (Y), it proceeds to 320 and determines that the circuit has a short circuit fault, and then the process ends directly at 324. If it is not (N), it proceeds to box 322 and determines that the circuit does not have the detected fault (short circuit or open circuit), and the process ends at 324. It can be understood that the above intervals 1-3 can be determined according to different circuit parameter values ​​(for example Figure 2 The specific value range of interval 1-3 can be gradually determined by testing the Vout value of the circuit under short circuit and open circuit faults for multiple times.

[0054] According to another aspect of the present disclosure, a vehicle-mounted buzzer control device is also provided. The vehicle-mounted buzzer control device may include the drive circuit fault detection system 100 or 200 according to any of the aforementioned embodiments. For example, the vehicle-mounted buzzer may be Figure 1 or Figure 2 The load RL (device under test) is shown in FIG.

[0055] According to another aspect of the present disclosure, a vehicle is also provided, which may include the drive circuit fault detection system 100 or 200 according to any of the foregoing embodiments, or may include the vehicle-mounted buzzer control device according to any of the foregoing embodiments. The vehicle referred to in this application is intended to represent any appropriate vehicle having a drive system, for example, a fuel-powered vehicle, a hybrid vehicle, an electric vehicle, a plug-in hybrid electric vehicle, etc.

[0056] The above mainly describes the drive circuit fault detection system and method, vehicle-mounted buzzer control device and vehicle disclosed in the present invention. Although only some of the specific embodiments of the present invention are described, it should be understood by those skilled in the art that the present invention can be implemented in many other forms without departing from its subject matter and scope. Therefore, the examples and embodiments shown are regarded as illustrative rather than restrictive, and the present invention may cover various modifications and substitutions without departing from the spirit and scope of the present invention as defined in the appended claims.

Claims

1. A drive circuit fault detection system, characterized in that: include: A first switch module, comprising a first transistor, wherein a base of the first transistor receives a control signal input, and a collector outputs a first switch signal; A second switch module, comprising a second transistor, a base of the second transistor receiving the first switch signal, an emitter receiving an input of a power supply voltage terminal, and a collector of the second transistor connected to a device under test; as well as The detection module is connected to the collector of the second transistor and converts its level signal into a direct current level, wherein the value of the direct current level is used to determine the fault type of the device under test.

2. The drive circuit fault detection system according to claim 1, characterized in that: The second switch module also includes a third transistor, the collector of the third transistor is connected to the base of the second transistor, the base of the third transistor is connected to the emitter of the second transistor and the base of the second transistor, and the emitter of the second transistor and the emitter of the third transistor receive the input of the power supply voltage terminal.

3. The drive circuit fault detection system according to claim 2, characterized in that: The first switch module further includes a first resistor, wherein the first resistor is connected between the collector of the first transistor and a first connection point, and the first connection point is connected to the base of the second transistor and the collector of the third transistor.

4. The drive circuit fault detection system according to claim 2, characterized in that: The second switch module also includes a second resistor, which is connected between a second connection point and a third connection point, the second connection point connects the base of the third transistor and the emitter of the second transistor, and the third connection point connects the emitter of the third transistor and the power supply voltage terminal.

5. The drive circuit fault detection system according to claim 4, characterized in that: The resistance value of the second resistor is determined according to the base-emitter voltage of the third transistor and the rated current of the device under test.

6. The drive circuit fault detection system according to claim 2, characterized in that: The second transistor and the third transistor are both PNP transistors.

7. The drive circuit fault detection system according to claim 1, characterized in that: The detection module also includes a second capacitor and a fourth resistor, the first end of the fourth resistor is connected to the collector of the second transistor and the second end is connected to the output end outputting the DC level, the first end of the second capacitor is connected to the output end outputting the DC level and the second end is grounded.

8. A drive circuit fault detection method, characterized in that: The drive circuit fault detection method is used in a drive circuit fault detection system according to any one of claims 1 to 7, comprising the following steps: In response to the value of the DC level being within a first predetermined fault range value, determining that an open circuit fault exists in the circuit under test; In response to the value of the DC level being within a second predetermined fault range, determining that the circuit under test has a short circuit to power supply or a short circuit to ground fault; as well as The frequency of the voltage signal at the collector of the second transistor is determined according to the DC level, and a driving frequency fault of the device under test is determined according to the frequency.

9. A vehicle-mounted buzzer control device, characterized in that: The vehicle-mounted buzzer control device comprises a drive circuit fault detection system according to any one of claims 1-7.

10. A vehicle, characterized in that: The vehicle comprises the drive circuit fault detection system according to any one of claims 1 to 7, or comprises the vehicle-mounted buzzer control device according to claim 9.

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