Buzzer circuit system and detection method

Abstract

The invention relates to a buzzer circuit system, and the circuit system comprises a working circuit which comprises an oscillation part with a buzzer, and the oscillation part can start oscillation according to an input working voltage, so as to enable the buzzer to make a sound; a sampling circuit that collects a voltage output from the oscillation portion to form a sampled voltage; and the processing circuit is configured to perform waveform shaping on the sampling voltage and determine the state of the working circuit at least based on the pulse width time of the shaped signal. The invention further relates to a method for detecting the state of the working circuit comprising the buzzer, a computer readable storage medium, a computer program product and a micro-control unit MCU.

Description

Technical Field

[0001] The present application relates to the detection of a buzzer, and in particular, to a buzzer circuit system, a detection circuit system of a buzzer circuit, a method for detecting the state of a working circuit including a buzzer, a computer-readable storage medium, a computer program product, and a microcontroller unit MCU. Background Art

[0002] Buzzers have been widely used as a component of alarm systems. However, the buzzer circuit itself is also prone to failure due to short circuit, open circuit and other faults, which can cause the buzzer to fail. Once the buzzer fails to work properly, the alarm signal cannot be output in time. If this happens at a disaster site such as a fire, it will be extremely dangerous.

[0003] In the prior art, there are solutions that rely on manual detection, such as manually controlling each buzzer to sound, and then the detection personnel determine whether each buzzer is working properly by listening. This manual detection solution is inefficient and cannot determine the working status of the buzzer or locate the fault in time.

[0004] In addition, in the prior art, there is a method of determining the working state of the buzzer by comparing the sampled voltage with the reference voltage (i.e., voltage comparison). However, this voltage comparison method can only determine two working states of the buzzer, which cannot meet the current need to test multiple working states. Summary of the invention

[0005] According to one aspect of the present application, a buzzer circuit system is provided, which includes: a working circuit, which includes an oscillation part having a buzzer, and the oscillation part can oscillate according to an input working voltage so that the buzzer makes a sound; a sampling circuit, which collects the voltage output from the oscillation part to form a sampling voltage; and a processing circuit, which is configured to perform waveform shaping on the sampling voltage and determine the state of the working circuit based on at least the pulse width time of the shaped signal.

[0006] As a supplement or alternative to the above scheme, in the above circuit system, the processing circuit includes: a Schmitt trigger circuit for shaping the sampled voltage into a square wave waveform; and a determination circuit for determining the state of the working circuit according to the pulse width time of the square wave waveform.

[0007] As a supplement or replacement for the above solution, the above circuit system also includes: a switch circuit for controlling whether the working circuit is working.

[0008] As a supplement or alternative to the above scheme, in the above circuit system, the switching circuit is configured to receive an excitation pulse control signal from the processing circuit and control the working circuit to operate within a pulse time, and the determination circuit is configured to: when the pulse width time of the shaped signal is greater than a first threshold, determine that the working circuit is in a normal working state; and when the pulse width time is less than a second threshold, determine that the buzzer in the working circuit is open, wherein the first threshold is greater than the second threshold.

[0009] As a supplement or alternative to the above scheme, in the above circuit system, the processing circuit is also configured to: determine that the inductor in the working circuit is open when the shaped signal is a low pulse and there is no signal oscillation; and determine that the working circuit is short-circuited when the shaped signal is a stabilized signal.

[0010] As a supplement or alternative to the above scheme, in the above circuit system, the sampling circuit includes: a clamping circuit, coupled to the processing circuit, for clamping the peak value of the sampling voltage below a preset threshold; a voltage divider circuit, coupled to the clamping circuit, for providing a steady-state voltage; and a capacitor, one end of the capacitor is coupled to the voltage divider circuit, and the other end is coupled to the working circuit.

[0011] As a supplement or alternative to the above solution, in the above circuit system, the capacitance of the capacitor is smaller than the equivalent capacitance of the buzzer.

[0012] According to another aspect of the present application, a method for detecting the state of a working circuit including a buzzer is provided, the method comprising: applying an excitation pulse control signal to a switching circuit so as to control the working circuit to operate within a pulse time, wherein the switching circuit is coupled to the working circuit, and the working circuit has an oscillation part of a buzzer; receiving a sampling voltage formed by the output of the oscillation part via a sampling circuit, and waveform shaping the sampling voltage; and determining the state of the working circuit based at least on the pulse width time of the shaped signal.

[0013] As a supplement or replacement of the above solution, in the above method, performing waveform shaping on the sampled voltage includes: shaping the sampled voltage into a square wave waveform using a Schmitt trigger circuit.

[0014] As a supplement or alternative to the above solution, in the above method, determining the state of the working circuit at least based on the pulse width time of the shaped signal includes: determining the state of the working circuit according to the pulse width time of the square wave waveform.

[0015] As a supplement or alternative to the above-mentioned scheme, in the above-mentioned method, determining the state of the working circuit at least based on the pulse width time of the shaped signal includes: when the pulse width time of the shaped signal is greater than a first threshold, determining that the working circuit is in a normal working state; and when the pulse width time is less than a second threshold, determining that the buzzer in the working circuit is open, wherein the first threshold is greater than the second threshold.

[0016] As a supplement or alternative to the above-mentioned scheme, in the above-mentioned method, determining the state of the working circuit based at least on the pulse width time of the shaped signal also includes: when the shaped signal is a low pulse and there is no signal oscillation, determining that the inductor in the working circuit is open-circuited; and when the shaped signal is a regulated signal, determining that the working circuit is short-circuited.

[0017] According to another aspect of the present application, a computer-readable storage medium is provided, wherein instructions are stored in the computer-readable storage medium. When the instructions are executed by a processor, the processor executes the method as described above.

[0018] According to another aspect of the present application, a computer program is provided, which implements the above-mentioned method when executed by a processor.

[0019] According to yet another aspect of the present application, a micro control unit MCU is provided, wherein the micro control unit is configured to execute the above-mentioned method.

[0020] The buzzer circuit system and detection method of the embodiment of the present application can determine four states of the working circuit (e.g., normal, short circuit, buzzer disconnection, and inductor disconnection) based at least on the pulse width time of the (shaped) signal, which is conducive to increasing the reliability of the entire circuit system. In addition, the detection method of the embodiment of the present application can help customers quickly locate faults and save troubleshooting time.

[0021] Moreover, the processing circuit in the buzzer circuit system of the embodiment of the present application can use a microcontroller unit MCU and receive the sampling signal with a general pin instead of an ADC module, saving the resources of the microcontroller unit MCU. In addition, the buzzer circuit system of the embodiment of the present application uses a clamping circuit included in the sampling circuit to limit the peak value of the sampling voltage provided to the processing circuit (such as the microcontroller unit MCU) to avoid damage to the internal components of the processing circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The above and other objects and advantages of the present application will become more fully apparent from the following detailed description in conjunction with the accompanying drawings, wherein the same or similar elements are represented by the same reference numerals.

[0023] Figure 1A schematic structural diagram of a buzzer circuit system according to an embodiment of the present application is shown;

[0024] Figure 2 A circuit diagram of a buzzer circuit system according to an embodiment of the present application is shown;

[0025] Figures 3 to 6 A waveform diagram showing a sampled voltage after applying an excitation pulse control signal to a switch circuit according to multiple embodiments of the present application; and

[0026] Figure 7 A flow chart of a method for detecting the state of a working circuit including a buzzer according to an embodiment of the present application is shown. DETAILED DESCRIPTION

[0027] For the purpose of brevity and illustration, the principles of the present application 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 all types of buzzer circuit systems, buzzer circuit detection circuit systems, methods for detecting the working state of buzzer circuits, and computer-readable storage media, and that these same or similar principles may be implemented therein, and any such changes do not depart from the true spirit and scope of the present application.

[0028] Figure 1 FIG. 1 shows a schematic diagram of a buzzer circuit system 1000 according to an embodiment of the present application. Figure 1 As shown, the buzzer circuit system 1000 includes: a working circuit 110, a sampling circuit 120 and a processing circuit 130, wherein the working circuit 110 includes an oscillating part ( Figure 1 ), and the oscillating part can oscillate according to the input working voltage so that the buzzer can sound; the sampling circuit 120 collects the voltage output from the oscillating part to form a sampling voltage; and the processing circuit 130 is configured to perform waveform shaping on the sampling voltage and determine the state of the working circuit 110 based on at least the pulse width time of the shaped signal. In one embodiment, the buzzer circuit system 1000 may also include: a switch circuit 140, which is used to control whether the working circuit 110 is working.

[0029] In one or more embodiments, the working circuit 110 includes an oscillating part having a buzzer, and the oscillating part can start to oscillate according to the input working voltage so that the buzzer sounds. For example, the core components of the oscillating part are an inductor and a capacitor (for example, the buzzer has a certain equivalent capacitance value), and the two will constitute an LC oscillation circuit. It should be understood that when any component of the oscillating part (for example, the inductor or the buzzer) has a short circuit, an open circuit, or other problems, the buzzer will work abnormally.

[0030] The sampling circuit 120 is used to collect the voltage output from the oscillating part of the working circuit 110 to form a sampling voltage. Figure 1 Not shown in the figure, the sampling circuit 120 may include: a clamping circuit coupled to the processing circuit 130, used to clamp the peak value of the sampling voltage below a preset threshold; a voltage divider circuit coupled to the clamping circuit, used to provide a steady-state voltage; and a capacitor, one end of the capacitor is coupled to the voltage divider circuit, and the other end is coupled to the working circuit 110. In one or more embodiments, the capacitance of the capacitor is smaller than the equivalent capacitance of the buzzer.

[0031] The processing circuit 130 is configured to perform waveform shaping on the sampled voltage and determine the state of the working circuit 110 based at least on the pulse width time of the shaped signal. In one embodiment, the processing circuit 130 includes: a Schmitt trigger circuit for shaping the sampled voltage into a square wave waveform (for example, the positive threshold voltage is 2.7V, and the negative threshold voltage is 0.9V); and a determination circuit for determining the state of the working circuit 110 according to the pulse width time of the square wave waveform. For example, the processing circuit 130 can be implemented in the form of a microcontroller unit MCU, and the pins of the microcontroller unit MCU can be equipped with a Schmitt trigger circuit to shape the received sampled voltage. Including a Schmitt trigger circuit in the processing circuit 130 to shape the sampled voltage can improve the accuracy of the final determination of the state of the working circuit 110 and enhance the anti-interference ability of the entire buzzer circuit system 1000.

[0032] In one or more embodiments, the switch circuit 140 is configured to receive the excitation pulse control signal from the processing circuit 130 and control the working circuit 110 to work within a pulse time (e.g., several microseconds). At this time, since the working time of the working circuit 110 is extremely short, the buzzer has not sounded yet (or the sound is almost inaudible), which ensures that the buzzer circuit system 1000 can be tested without being noticed. In one embodiment, the determination circuit in the processing circuit 130 can be configured to: when the pulse width time of the shaped signal is greater than a first threshold, determine that the working circuit 110 is in a normal working state (when the working circuit 110 is in a normal state, the frequency of the oscillation waveform output by the oscillation part in the working circuit 110 is determined by the inductor L1 in the oscillation part and the equivalent capacitance C1 of the buzzer, and the pulse width obtained at this time is the widest); and when the pulse width time is less than a second threshold, determine that the buzzer in the working circuit 110 is open-circuited, wherein the first threshold is greater than the second threshold (when the buzzer is open-circuited, the inductor L1 in the oscillation part and the capacitor C2 in the sampling circuit 120 form a series resonance, and a very high-frequency oscillation waveform will be obtained, and the pulse width is very narrow at this time).

[0033] In one embodiment, the processing circuit 130 is further configured to: determine that the inductor in the working circuit 110 is open-circuited when the shaped signal is a low pulse and there is no signal oscillation (when the inductor is open-circuited, there is no oscillation in the oscillation part, but there will be a low pulse due to the equivalent capacitor C1 of the buzzer); and determine that the working circuit 110 is short-circuited when the shaped signal is a stabilized voltage signal (when the working circuit 110 is short-circuited, there is no oscillation and the sampling voltage should be stable).

[0034] Figure 2 FIG. 2 shows a circuit diagram of a buzzer circuit system 2000 according to an embodiment of the present application. Figure 2 As shown, the buzzer circuit system 2000 includes a working circuit 210, a sampling circuit 220, a processing circuit 230 and a switch circuit 240. The working circuit 210 includes an oscillation circuit (oscillation part) composed of an inductor L1 and an equivalent capacitor C1 of a buzzer 215, wherein one end of the inductor L1 is coupled to a working voltage V1 (for example, 24V), and the other end is respectively coupled to the sampling circuit 220 and the switch circuit 240. It can be understood that if the oscillation part can oscillate normally, the illustrated buzzer 215 can sound normally.

[0035] The sampling circuit 220 collects the voltage output from the working circuit 210 (or the oscillating part) to form a sampling voltage A3 to provide to the processing circuit 230. Figure 2 As shown, the sampling circuit 220 includes a clamping circuit 222 , a voltage divider circuit 224 and a capacitor C2 , wherein the capacitor C2 is coupled between the voltage divider circuit 224 and the working circuit 210 , and the clamping circuit 222 is coupled between the voltage divider circuit 224 and the processing circuit 230 .

[0036] Continue to refer Figure 2 The clamping circuit 222 is composed of a diode D2 and a diode D3 connected in series, wherein one end of the diode D2 is coupled to a power supply (e.g., 3.3V), the other end of the diode D2 is coupled to one end of the diode D3, and the other end of the diode D3 is grounded. The sampling voltage A3 output by the sampling circuit 220 is clamped within a certain range by the two diodes. For example, assuming that the conduction thresholds of the diodes D2 and D3 are both 0.3V and the external power supply is 3.3V, the range is [-0.3V, 3.6V]. In other words, the peak value of the sampling voltage A3 will not exceed 3.6V, which effectively protects the components inside the processing circuit 230.

[0037] In addition, the voltage divider circuit 224 is formed by a resistor R1 and a resistor R2 connected in series, and is used to provide a steady-state voltage. For example, when the resistance values ​​of the resistors R1 and R2 are equal, the voltage divider circuit 224 can provide a steady-state voltage of 3.3V / 2=1.65V.

[0038] Capacitor C2 is coupled between the voltage divider circuit 224 and the working circuit 210, and can play at least two roles: (1) "isolate DC and pass AC", that is, isolate the DC voltage from the working circuit 210 and pass the high-frequency voltage signal from the working circuit 210; (2) when the buzzer is open, it forms a series resonance with the inductor L1 in the working circuit 210 to generate a certain oscillation waveform. Since the capacitance value of capacitor C2 is generally smaller than the capacitance value of the equivalent capacitor C1 of the buzzer 215, the frequency of the oscillation waveform formed by the inductor L1 and the capacitor C2 is higher (greater than the frequency of the oscillation waveform formed by the inductor L1 and the equivalent capacitor C1). This can result in a narrower pulse width time of the sampled voltage A3 collected by the sampling circuit 220 after shaping.

[0039] like Figure 2 As shown, the switch circuit 240 is composed of a transistor Q1 and a diode D1, wherein the base of the transistor Q1 is coupled to the processing circuit 230, the emitter of the transistor Q1 is grounded, the collector of the transistor Q1 is coupled to one end of the diode D1, and the other end of the diode D1 is coupled to the inductor L1 in the working circuit 210. Those skilled in the art will appreciate that the configuration of the switch circuit 240 is not limited to the following. Figure 2 The specific structure shown, for example, the transistor Q1 can be replaced by a MOS transistor, an IGBT transistor, etc., and this application does not limit this.

[0040] In one embodiment, in order to detect the state of the working circuit 210 including the buzzer 215 , the processing circuit 230 is configured to apply an excitation pulse control signal to the switch circuit 240 so as to control the working circuit 210 to work within a pulse time. Figure 3 FIG. 2 shows a waveform diagram of the sampling voltage obtained by the sampling circuit 220 after the processing circuit 230 applies an excitation pulse control signal to the switch circuit 240 when the working circuit 210 is in a normal working state. Figure 3 As shown, the excitation pulse control signal is represented by FIG310, and the waveform of the sampling voltage obtained by the sampling circuit 220 is represented by FIG320. Figure 3 It can be seen that when the working circuit 210 is in a normal working state, the sampled voltage is a sine wave. Figure 3 The lower half of the schematic diagram also shows the amplified excitation pulse control signal 315 and the sampled voltage signal 325 for the dotted box 330. Figure 3In the embodiment of FIG. 3 , the pulse time of the excitation pulse control signal 315 is 33 μs, and the pulse time of the obtained sampled voltage signal 325 is 300 μs. That is, after applying an excitation pulse control signal of a very short time (e.g., 33 μs) to the switch circuit 240 (as shown in the waveform 315), the sampling circuit 220 can subsequently obtain several 300 μs pulse signals (as shown in the waveform 325).

[0041] Figure 4 It shows that when the working circuit 210 is in a state where the inductor L1 is disconnected, the processing circuit 230 applies an excitation pulse control signal (waveform as shown in FIG. 1 ) to the switch circuit 240. Figure 4 The waveform 420 of the sampled voltage obtained by the sampling circuit 220 is shown in FIG. Figure 4 In the embodiment of FIG. 4 , the pulse width of waveform 420 is 127 μs. Figure 4 It can be seen that when the inductor L1 is open, there is no oscillation in the oscillation part, but there will be a low pulse due to the existence of the equivalent capacitor C1 of the buzzer.

[0042] Figure 5 It shows that when the working circuit 210 is in a short-circuit state, the processing circuit 230 applies an excitation pulse control signal (waveform as shown in FIG. Figure 5 510 in FIG. 5 shows a waveform 520 of the sampled voltage obtained by the sampling circuit 220 after the working circuit 210 is short-circuited. Since the working circuit 210 is short-circuited, the capacitor C2 (e.g., 150 pF) is directly connected to the power supply, and the final sampled voltage is as low as 1.644 V. After the waveform is shaped by the processing circuit 230 (e.g., by a Schmitt trigger circuit), no low pulse is generated. That is, when the working circuit 210 is short-circuited, there is no oscillation at this time, and the sampled voltage should be relatively stable.

[0043] Figure 6 It shows that when the working circuit 210 is in the buzzer open circuit state, the processing circuit 230 applies an excitation pulse control signal to the switch circuit 240 (waveform as shown in FIG. Figure 6 610 in the figure) is a waveform 620 of the sampled voltage obtained by the sampling circuit 220. When the buzzer is open, the inductor L1 in the oscillation part and the capacitor C2 in the sampling circuit 220 form a series resonance, and a very high frequency oscillation waveform is obtained, and the pulse width is very narrow at this time. In one embodiment, the pulse time of the excitation pulse control signal 610 is 9 μs, and the pulse time of the obtained sampled voltage signal 620 is 12 μs.

[0044] based on Figures 3 to 6 In one embodiment, the processing circuit 230 may determine the state of the working circuit 210 based on the following table:

[0045]

[0046] The processing circuit 230 can determine the four states of the working circuit 210 based on the pulse width time in the above table. In one embodiment, in addition to the pulse width time, the processing circuit 230 can further determine the working state of the working circuit 210 based on the overall continuous pulse time of the obtained sampling voltage and / or the waveform characteristics of the sampling voltage. The above detection of the buzzer circuit system 2000 is conducive to increasing its reliability, helping customers to quickly locate faults and save troubleshooting time.

[0047] In addition, the processing circuit 230 in the buzzer circuit system 2000 can adopt a micro control unit MCU and receive the sampling signal through a general pin instead of an ADC module, which can save the hardware resources of the micro control unit MCU.

[0048] Figure 7 FIG. 7 is a flow chart of a method 7000 for detecting the state of a working circuit including a buzzer according to an embodiment of the present application. Figure 7 As shown, the method 7000 includes the following steps:

[0049] In step S710, applying an excitation pulse control signal to a switch circuit so as to control the working circuit to work within a pulse time, wherein the switch circuit is coupled to the working circuit, and the working circuit has an oscillation part of a buzzer;

[0050] In step S720, a sampling circuit receives a sampling voltage formed by the output of the oscillating part, and performs waveform shaping on the sampling voltage; and

[0051] In step S730, the state of the working circuit is determined based on at least the pulse width time of the shaped signal.

[0052] In one embodiment, step S720 includes: shaping the sampled voltage into a square wave waveform using a Schmitt trigger circuit. In one embodiment, step S730 includes: determining the state of the working circuit according to the pulse width time of the square wave waveform. For example, when the pulse width time of the shaped signal is greater than a first threshold, it is determined that the working circuit is in a normal working state; and when the pulse width time is less than a second threshold, it is determined that the buzzer in the working circuit is open, wherein the first threshold is greater than the second threshold. For another example, when the shaped signal is a low pulse and there is no signal oscillation, it is determined that the inductor in the working circuit is open; and when the shaped signal is a voltage-regulated signal, it is determined that the working circuit is short-circuited.

[0053] According to another aspect of the present application, a computer-readable storage medium is provided, in which instructions are stored. When the instructions are executed by a processor, the processor executes the method 7000 for detecting the state of a working circuit including a buzzer as described above. The computer-readable medium referred to in the present application includes various types of computer storage media, which can be any available medium that can be accessed by a general-purpose or special-purpose computer. For example, the computer-readable medium can include RAM, ROM, EPROM, EEPROM, etc. 2 PROM, register, hard disk, removable disk, CD-ROM or other optical disk storage, disk storage or other magnetic storage device, or can be used to carry or store the desired program code unit in the form of instruction or data structure and can be accessed by general or special computer, or general or special processor. As used herein, the disk usually copies data magnetically, while the dish uses laser to optically copy data. The above combination should also be included in the protection scope of computer-readable medium. Exemplary storage medium is coupled to the processor so that the processor can read and write information from / to the storage medium. In an alternative solution, the storage medium can be integrated into the processor. The processor and the storage medium can reside in the ASIC. The ASIC can reside in the user terminal. In an alternative solution, the processor and the storage medium can reside in the user terminal as discrete components.

[0054] In addition, it is easy for a person skilled in the art to understand that the method 7000 for detecting the state of a working circuit including a buzzer according to one or more embodiments of the present application can be implemented by a computer program. For example, the computer program is included in a computer program product, and when the computer program is executed by a processor, the method 7000 for detecting the state of a working circuit including a buzzer according to one or more embodiments of the present application is implemented.

[0055] According to yet another aspect of the present application, a micro control unit MCU is provided, wherein the micro control unit is configured to execute the method 7000 for detecting the state of a working circuit including a buzzer as described above.

[0056] The above are only specific implementations of the present application, but the protection scope of the present application is not limited thereto. Those skilled in the art can think of other feasible changes or substitutions based on the technical scope disclosed in the present application, and such changes or substitutions are all included in the protection scope of the present application. In the absence of conflict, the implementation modes of the present application and the features in the implementation modes can also be combined with each other. The protection scope of the present application shall be subject to the description of the claims.

Claims

1. A buzzer circuit system, characterized in that: The circuit system comprises: A working circuit, comprising an oscillating part having a buzzer, and the oscillating part can oscillate according to an input working voltage so as to make the buzzer sound; a sampling circuit that samples the voltage output from the oscillation part to form a sampling voltage; and The processing circuit is configured to perform waveform shaping on the sampled voltage and determine the state of the working circuit based at least on the pulse width time of the shaped signal.

2. The circuit system of claim 1, wherein: The processing circuit comprises: A Schmitt trigger circuit, used for shaping the sampled voltage into a square wave waveform; and A determination circuit is used to determine the state of the working circuit according to the pulse width time of the square wave waveform.

3. The circuit system of claim 2, further comprising: The switch circuit is used to control whether the working circuit is working.

4. The circuit system of claim 3, wherein: The switch circuit is configured to receive the excitation pulse control signal from the processing circuit and control the working circuit to work within a pulse time, and the determination circuit is configured to: When the pulse width time of the shaped signal is greater than a first threshold, determining that the working circuit is in a normal working state; as well as When the pulse width time is less than a second threshold, it is determined that the buzzer in the working circuit is open, wherein the first threshold is greater than the second threshold.

5. The circuit system of claim 4, wherein: The processing circuit is further configured to: When the shaped signal is a low pulse and there is no signal oscillation, determining that the inductor in the working circuit is open; and When the shaped signal is a voltage-stabilized signal, it is determined that the working circuit is short-circuited.

6. The circuit system of claim 1, wherein: The sampling circuit comprises: A clamping circuit, coupled to the processing circuit, for clamping the peak value of the sampled voltage below a preset threshold; a voltage divider circuit, coupled to the clamp circuit, for providing a steady-state voltage; and A capacitor, one end of which is coupled to the voltage divider circuit, and the other end of which is coupled to the working circuit.

7. The circuit system of claim 6, wherein: The capacitance of the capacitor is smaller than the equivalent capacitance of the buzzer.

8. A method for detecting the state of a working circuit including a buzzer, characterized in that: The method comprises: Applying an excitation pulse control signal to a switch circuit so as to control the working circuit to work within a pulse time, wherein the switch circuit is coupled to the working circuit, and the working circuit has an oscillation part of a buzzer; receiving a sampling voltage formed by the output of the oscillation part via a sampling circuit, and performing waveform shaping on the sampling voltage; and The state of the operating circuit is determined based at least on the pulse width time of the shaped signal.

9. The method of claim 8, wherein: Performing waveform shaping on the sampled voltage includes: The sampling voltage is shaped into a square wave waveform by using a Schmitt trigger circuit.

10. The method of claim 9, wherein: Determining the state of the working circuit based at least on the pulse width time of the shaped signal includes: The state of the working circuit is determined according to the pulse width time of the square wave waveform.

11. The method according to claim 8 or 10, wherein: Determining the state of the working circuit based at least on the pulse width time of the shaped signal includes: When the pulse width of the shaped signal is greater than a first threshold, determining that the working circuit is in a normal working state; and When the pulse width time is less than a second threshold, it is determined that the buzzer in the working circuit is open, wherein the first threshold is greater than the second threshold.

12. The method of claim 8, wherein: Determining the state of the working circuit based at least on the pulse width time of the shaped signal further includes: When the shaped signal is a low pulse and there is no signal oscillation, determining that the inductor in the working circuit is open; and When the shaped signal is a voltage-stabilized signal, it is determined that the working circuit is short-circuited.

13. A computer-readable storage medium, wherein instructions are stored in the computer-readable storage medium, characterized in that: When the instructions are executed by a processor, the processor is caused to perform the method according to any one of claims 8 to 12.

14. A computer program product comprising a computer program, characterized in that When the computer program is executed by a processor, the method according to any one of claims 8 to 12 is implemented.

15. A micro control unit MCU, characterized in that: The micro control unit is configured to perform the method according to any one of claims 8 to 12.

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