Circuit for eliminating power-off POP sound of loudspeaker and audio equipment

Abstract

The utility model relates to the technical field of audio power amplifiers, and discloses a circuit for eliminating power-off POP sound of a loudspeaker and audio equipment, after the audio power amplifier is started, a power supply charges an energy storage circuit, and a switching circuit is connected with the power supply, so that the voltage difference between a first end and a third end of the switching circuit enables the switching circuit to be in an off state; when the power supply is powered off, the energy storage circuit starts to discharge, the discharge of the energy storage circuit causes the voltage difference between the first end and the third end of the switching circuit to reach the starting voltage of the electronic switching component, the switching circuit is switched on at the moment, and the control end of the audio power amplifier is rapidly pulled down after the switching circuit is switched on; and before the power supply is dropped below the normal working voltage of the whole machine, the audio power amplifier is turned off, so that the loudspeaker is prevented from generating POP sound.

Description

TECHNICAL FIELD

[0001] The utility model relates to audio power amplifier technical field, concretely relates to a circuit and audio frequency equipment of eliminating loudspeaker power-off POP sound. BACKGROUND

[0002] With the pursuit of high-quality life of people, people's requirement to audio quality is also higher and higher. In public places, people usually use earphone to cooperate with terminal such as mobile phone, tablet computer to carry out audio output. However, in the process of earphone initialization, POP sound is often produced, which influences user's experience.

[0003] And adopt the audio power amplifier chip of supporting digital audio signal input, the power amplifier chip inside has the special processing to POP sound problem, so general power adapter suddenly power-off loudspeaker will not appear POP sound, but the audio power amplifier chip of supporting digital audio signal input, its defects mainly have following two points:

[0004] (1) design scheme is complex, and function realization involves software, and software and hardware combination debugging is needed to realize function. (2) cost is relatively high, and chip selectivity is also relatively less. INVENTION CONTENT

[0005] Therefore, the utility model provides a circuit and audio frequency equipment of eliminating loudspeaker power-off POP sound to solve how to utilize hardware circuit to realize the problem of eliminating loudspeaker power-off POP sound.

[0006] Firstly, the utility model provides a circuit of eliminating loudspeaker power-off POP sound, and it includes: energy storage circuit, switching circuit, wherein the first end of energy storage circuit is connected with the power supply of loudspeaker, and the second end of energy storage circuit is connected with the first end of switching circuit, the second end of switching circuit is connected with power supply, and the third end of switching circuit is connected with the control end of audio power amplifier of loudspeaker, and the third end of switching circuit is also connected with the controller of audio power amplifier, when power supply is normal, power supply charges energy storage circuit, and switching circuit is in off state, and controller controls the opening or closing of audio power amplifier, when power supply is powered off, energy storage circuit discharges to make switching circuit conduct, and audio power amplifier is closed.

[0007] The utility model discloses when in audio power amplifier start -up, the power supply charges the energy storage circuit, because switch circuit connects the power supply, therefore the voltage difference of the first end and the third end of switch circuit makes switch circuit always be in off state, and when the power supply is powered off, the energy storage circuit starts to discharge, and the discharge of energy storage circuit will lead to the voltage difference of the first end and the third end of switch circuit reaches the starting voltage of electronic switch component, at this moment, switch circuit is conducted, and after switch circuit is conducted, the control end of audio power amplifier will be rapidly pulled down, makes the power supply drop to below the normal working voltage of complete machine before, closes audio power amplifier, thereby avoiding that the loudspeaker produces POP sound.

[0008] In an alternative embodiment, the switch circuit comprises: a first switch sub-circuit and a second switch sub-circuit, wherein the first end of the first switch sub-circuit is connected to the second end of the energy storage circuit, the second end of the first switch sub-circuit is connected to the power supply, and the third end of the first switch sub-circuit is connected to the first end of the second switch sub-circuit; the second end of the second switch sub-circuit is connected to the control end of the audio power amplifier of the loudspeaker and the controller of the audio power amplifier; the third end of the second switch sub-circuit is grounded; when the power supply is normal, both the first switch sub-circuit and the second switch sub-circuit are off; when the power supply is powered off, the energy storage circuit discharges to make the first switch sub-circuit conductive, and then the second switch sub-circuit is conducted to pull down the control end of the audio power amplifier, and the audio power amplifier is turned off.

[0009] In an alternative embodiment, the first switch sub-circuit comprises: a first triode and a third resistor, wherein the emitter of the first triode is connected to the second end of the energy storage circuit, the base of the first triode is connected to the power supply through the third resistor, and the collector of the first triode is connected to the first end of the second switch sub-circuit; when the power supply is normal, the first triode is cut off; when the power supply is powered off, the energy storage circuit discharges to make the first triode conductive.

[0010] In an alternative embodiment, the second switch sub-circuit comprises: a second triode and a fourth resistor, wherein the base of the second triode is connected to the third end of the first switch sub-circuit through the fourth resistor, the emitter of the second triode is grounded, and the collector of the second triode is connected to the control end of the audio power amplifier of the loudspeaker and the controller of the audio power amplifier; when the power supply is normal, the second triode is cut off; when the power supply is powered off, the first triode is conducted, and then the second triode is conducted.

[0011] In an alternative embodiment, the energy storage circuit comprises: a voltage dividing circuit, a reverse prevention circuit and an energy storage capacitor, wherein the first end of the voltage dividing circuit is connected with the power supply of the loudspeaker, the second end of the voltage dividing circuit is connected with the first end of the reverse prevention circuit, and the second end of the voltage dividing circuit is grounded; the second end of the reverse prevention circuit is connected with the first end of the energy storage capacitor and the first end of the switching circuit; and the second end of the energy storage capacitor is grounded.

[0012] In an alternative embodiment, the voltage dividing circuit comprises: a first resistor and a second resistor, wherein the first end of the first resistor is connected with the power supply of the loudspeaker, the second end of the first resistor is connected with the first end of the second resistor and the first end of the reverse prevention circuit; and the second end of the second resistor is grounded.

[0013] In an alternative embodiment, the reverse prevention circuit comprises: a diode, wherein the anode of the diode is connected with the second end of the voltage dividing circuit, and the cathode of the diode is connected with the first end of the energy storage capacitor and the first end of the switching circuit.

[0014] In an alternative embodiment, the circuit for eliminating the POP sound of the loudspeaker during power-off further comprises: a filter circuit, wherein the first end of the filter circuit is connected with the third end of the switching circuit, and the second end of the filter circuit is grounded; and the filter circuit is used for filtering out the noise on the line.

[0015] In an alternative embodiment, the third end of the switching circuit is connected with the controller of the audio power amplifier through a fifth resistor.

[0016] In a second aspect, the utility model provides an audio equipment, comprising: an audio power amplifier and the circuit for eliminating the POP sound of the loudspeaker during power-off of the first aspect and any alternative embodiment. BRIEF DESCRIPTION OF DRAWINGS

[0017] In order to more clearly illustrate the specific embodiments of the utility model or the technical solutions in the prior art, the following will briefly introduce the drawings needed to be used in the description of the specific embodiments or the prior art. Obviously, the drawings described below are some embodiments of the utility model, and those skilled in the art can also obtain other drawings according to these drawings without creating any creative labor.

[0018] Figure 1 It is the composition diagram of the circuit for eliminating the POP sound of the loudspeaker during power-off according to the embodiments of the utility model;

[0019] Figure 2 It is the composition diagram of another circuit for eliminating the POP sound of the loudspeaker during power-off according to the embodiments of the utility model;

[0020] Figure 3 It is the specific circuit structure diagram of the circuit for eliminating the POP sound of the loudspeaker during power-off according to the embodiments of the utility model.

[0021] Figure 4 is another flowchart of a circuit for eliminating a POP sound of a loudspeaker power-off according to an embodiment of the present application;

[0022] Figure 5 is another flowchart of a circuit for eliminating a POP sound of a loudspeaker power-off according to an embodiment of the present application. DETAILED DESCRIPTION

[0023] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.

[0024] In the description of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second", "third" are only for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0025] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connection" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the communication between two elements inside, it can be wireless connection, or it can be wired connection. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0026] In addition, the technical features involved in the different embodiments of the present application described below can be combined with each other as long as there is no conflict.

[0027] The burst sound caused by the transient impact of various operations of the audio device at the power-on and power-off moment is the POP sound. In order to eliminate the POP sound, a circuit for eliminating the POP sound of a loudspeaker power-off is provided in the present embodiment, as shown in Figure 1As shown, it includes: energy storage circuit 1 and switching circuit 2.

[0028] like Figure 1 As shown, the first end of the energy storage circuit 1 is connected to the power supply of the speaker, and the second end of the energy storage circuit 1 is connected to the first end of the switching circuit 2.

[0029] like Figure 1 As shown, the second terminal of switch circuit 2 is connected to the power supply, the third terminal of switch circuit 2 is connected to the control terminal of the speaker's audio amplifier, and the third terminal of switch circuit 2 is also connected to the controller of the audio amplifier.

[0030] Specifically, when the power supply is normal, the power supply charges the energy storage circuit 1 and the switching circuit 2 is in the off state, and the controller controls the audio power amplifier to turn on or off; when the power supply fails, the energy storage circuit 1 discharges, causing the switching circuit 2 to turn on, and the audio power amplifier turns off.

[0031] Optionally, the energy storage circuit 1 incorporates energy storage components such as supercapacitors. After the audio power amplifier is started, the power supply charges the energy storage components, and when the power supply suddenly fails, the energy storage components discharge.

[0032] Optionally, the switching circuit 2 incorporates an electronic switching component. When the audio amplifier is started, the power supply charges the energy storage component. Since the switching circuit 2 is connected to the power supply, the voltage difference between the first and third terminals of the switching circuit 2 keeps the switching circuit 2 in an off state. When the power supply is turned off, the energy storage circuit 1 begins to discharge. The discharge of the energy storage circuit 1 will cause the voltage difference between the first and third terminals of the switching circuit 2 to reach the starting voltage of the electronic switching component. At this time, the switching circuit 2 is turned on. After the switching circuit 2 is turned on, it will pull down the control terminal of the audio amplifier, and finally turn off the audio amplifier in time. Thus, the pop sound can be eliminated by using only the energy storage circuit 1 and the switching circuit 2 in the form of hardware circuits.

[0033] Optionally, the controller can be a central processing unit (CPU). The controller can output a high level to the control terminal of the audio amplifier to control the audio amplifier to turn on, and output a low level to the control terminal of the audio amplifier to control the audio amplifier to turn off.

[0034] Specifically, when the power supply is normal and not interrupted, the controller can control the audio amplifier to turn on or off.

[0035] In some alternative implementations, such as Figure 2 As shown, the energy storage circuit 1 includes: a voltage divider circuit 11, an anti-reverse circuit 12, and an energy storage capacitor C1.

[0036] like Figure 2As shown, the first end of the voltage dividing circuit 11 is connected with the power supply of the loudspeaker, the second end of the voltage dividing circuit 11 is connected with the first end of the anti-reverse circuit 12, and the second end of the voltage dividing circuit 11 is grounded.

[0037] Specifically, after the audio power amplifier is started, the voltage dividing circuit 11 divides the voltage of the power supply, and the divided voltage charges the energy storage capacitor C1 through the anti-reverse circuit 12. Optionally, the voltage dividing circuit 11 is built-in with multiple resistors, which are connected in series, in parallel, or in a mixed connection of series and parallel, which is not limited herein.

[0038] As shown, Figure 2 the second end of the anti-reverse circuit 12 is connected with the first end of the energy storage capacitor C1 and the first end of the switch circuit 2.

[0039] Specifically, the anti-reverse circuit 12 has a one-way conduction property, so as to prevent the discharge current from flowing back to the power supply when the energy storage capacitor C1 is discharging, and the anti-reverse circuit 12 also has a further voltage reduction function. Optionally, the anti-reverse circuit 12 can include a diode D in Figure 3 The anode of the diode D is connected with the second end of the voltage dividing circuit 11 (i.e., the first resistor R1), and the cathode of the diode D is connected with the first end of the energy storage capacitor C1 and the first end of the switch circuit 2 (i.e., the emitter of the first triode).

[0040] As shown, Figure 2 the second end of the energy storage capacitor C1 is grounded. Specifically, Figure 2 only one energy storage capacitor C1 is shown in

[0041] In some optional embodiments, as shown, Figure 2 the voltage dividing circuit 11 includes a first resistor R1 and a second resistor R2, wherein the first end of the first resistor R1 is connected with the power supply of the loudspeaker (i.e., DC_12V), the second end of the first resistor R1 is connected with the first end of the second resistor R2 and the first end of the anti-reverse circuit 12 (i.e., the anode of the diode D), and the second end of the second resistor R2 is grounded.

[0042] In some optional embodiments, as shown, Figure 4 the switch circuit 2 includes a first switch sub-circuit 21 and a second switch sub-circuit 22.

[0043] As shown, Figure 4As shown, the first terminal of the first switching sub-circuit 21 is connected to the second terminal of the energy storage circuit 1, the second terminal of the first switching sub-circuit 21 is connected to the power supply, and the third terminal of the first switching sub-circuit 21 is connected to the first terminal of the second switching sub-circuit 22. Optionally, the first switching sub-circuit 21 incorporates an electronic switching device, and its conduction and cutoff are controlled by the voltage of the power supply and the voltage of the energy storage capacitor C1. Optionally, the first switching sub-circuit 21 incorporates an electronic switching device, and its conduction and cutoff are controlled by the voltage of the power supply and the voltage of the energy storage circuit 1.

[0044] like Figure 4 As shown, the second terminal of the second switch sub-circuit 22 is connected to the control terminal of the speaker's audio amplifier and the controller of the audio amplifier; the third terminal of the second switch sub-circuit 22 is grounded. Optionally, the first switch sub-circuit 21 has a built-in electronic switch device, and its conduction and cutoff are controlled by the conduction and cutoff of the first switch sub-circuit 21.

[0045] Specifically, when the power supply is normal, both the first switch sub-circuit 21 and the second switch sub-circuit 22 are turned off; when the power supply fails, the energy storage circuit 1 discharges, causing the first switch sub-circuit 21 to conduct, and then the second switch sub-circuit 22 to conduct, thereby pulling down the control terminal of the audio power amplifier and turning off the audio power amplifier.

[0046] In some alternative implementations, such as Figure 3 As shown, the first switching sub-circuit 21 includes a first transistor Q1 and a third resistor R3. The emitter of the first transistor Q1 is connected to the second terminal (i.e., the energy storage capacitor C1) of the energy storage circuit 1, the base of the first transistor Q1 is connected to the power supply through the third resistor R3, and the collector of the first transistor Q1 is connected to the first terminal (i.e., the base of the second transistor Q2) of the second switching sub-circuit 22. When the power supply is normal, the first transistor Q1 is cut off. When the power supply is de-energized, the energy storage circuit 1 discharges, causing the first transistor Q1 to conduct.

[0047] Specifically, after the audio power amplifier is started, the voltage of the power supply is stepped down twice by the voltage divider circuit 11 and the anti-reverse circuit 12 to charge the energy storage capacitor C1. The base voltage of the first transistor Q1 is the power supply voltage. Therefore, the base voltage of the first transistor Q1 is higher than its emitter voltage. Since the first transistor Q1 is an NPN insulated gate bipolar transistor (IGBT), the first transistor Q1 is reverse biased and is cut off.

[0048] Specifically, when the power supply is powered off, the base voltage of the first triode Q1 also decreases, and the emitter pin voltage of the first triode Q1 does not change temporarily because the energy storage capacitor C1 is fully charged. When the base voltage of the first triode Q1 decreases to about 0.7 V lower than the emitter voltage, the first triode Q1 is turned on.

[0049] In some optional embodiments, as shown in Figure 3 The second switch sub-circuit 22 includes a second triode Q2 and a fourth resistor R4. The base of the second triode Q2 is connected to the third end of the first switch sub-circuit 21 (i.e., the collector of the first triode Q1) through the fourth resistor R4. The emitter of the second triode Q2 is grounded. The collector of the second triode Q2 is connected to the control end of the audio power amplifier of the loudspeaker and the controller of the audio power amplifier. When the power supply is normal, the second triode Q2 is cut off. When the power supply is powered off, the first triode Q1 is turned on, and the second triode Q2 is turned on. Specifically, when the first triode Q1 is cut off, the second triode Q2 is cut off because it is a PNP type IGBT, and the SD end of the audio power amplifier is controlled by the controller connected to the SPK_EN end. When the first triode Q1 is turned on, the second triode Q2 is turned on, the SD end is pulled low, and the audio power amplifier is turned off. Therefore, before the power supply voltage drops below the normal working voltage of the whole machine, the audio power amplifier is turned off, thereby avoiding the POP sound of the loudspeaker.

[0050] It should be noted that, Figure 3 The SD end in the controller is the control end of the audio power amplifier. The collector of the second triode Q2 is connected to the general purpose input / output port (i.e., General Purpose Input / Output, abbreviated as GPIO) of the controller. The controller sends a trigger signal to the second triode Q2 through the GPIO to control the conduction or turn-off of the second triode Q2. In some optional embodiments, as shown in Figure 5 The circuit for eliminating the POP sound of the loudspeaker when the power supply is powered off further includes a filter circuit 3. The first end of the filter circuit 3 is connected to the third end of the switch circuit 2, and the second end of the filter circuit 3 is grounded. The filter circuit 3 is used to filter out the noise on the line.

[0051] In some optional embodiments, as shown in Figure 3 The filter circuit 3 includes a filter capacitor C2 and a filter resistor R5. The first end of the filter capacitor C2 and the first end of the filter resistor R5 are connected to the third end of the switch circuit 2 (i.e., the collector of the second triode Q2). The second end of the filter capacitor C2 and the second end of the filter resistor R5 are both grounded.

[0052] Specifically, the filter capacitor C2 and the filter resistor R5 are connected in parallel to form an RC filter circuit to prevent interference of noise on the control signal.

[0053] In some optional embodiments, as shown in Figure 3 The circuit for eliminating the POP sound of the loudspeaker during power-off further comprises: the third end of the switch circuit 2 is connected with the controller of the audio power amplifier through the fifth resistor R6. The control end of the audio power amplifier is actually connected with the GPIO end of the controller. In order to realize impedance matching and prevent interference, the fifth resistor R6 is arranged on the circuit.

[0054] In the embodiment, an audio device is provided, which comprises: an audio power amplifier and the circuit for eliminating the POP sound of the loudspeaker during power-off in the above embodiment and any optional embodiment thereof.

[0055] Optionally, the audio power amplifier is an audio power amplifier, which is a power amplifier device for driving a loudspeaker to produce sound, so as to reproduce sound. The audio power amplifier is used in any audio device for producing sound, and the audio device is not limited to a smart speaker, a WIFI speaker, a Bluetooth speaker, a vehicle-mounted speaker, etc.

[0056] Specifically, as shown in Figure 1 The circuit for eliminating the POP sound of the loudspeaker during power-off comprises: an energy storage circuit 1 and a switch circuit 2. The first end of the energy storage circuit is connected with the power supply of the loudspeaker, and the second end of the energy storage circuit is connected with the first end of the switch circuit. The second end of the switch circuit is connected with the power supply, and the third end of the switch circuit is connected with the control end of the audio power amplifier of the loudspeaker and the controller of the audio power amplifier. When the power supply is normal, the power supply charges the energy storage circuit, and the switch circuit is in an off state. The controller controls the opening and closing of the audio power amplifier. When the power supply is powered off, the energy storage circuit discharges to make the switch circuit conductive, and the control end of the audio power amplifier is pulled low, and the audio power amplifier is closed.

[0057] In the utility model, when the audio power amplifier is started, the power supply charges the energy storage circuit. Since the switch circuit is connected with the power supply, the voltage difference between the first end and the third end of the switch circuit makes the switch circuit always in an off state. When the power supply is powered off, the energy storage circuit starts to discharge. The discharge of the energy storage circuit will cause the voltage difference between the first end and the third end of the switch circuit to reach the starting voltage of the electronic switch component. At this time, the switch circuit is conductive. After the switch circuit is conductive, the control end of the audio power amplifier is quickly pulled low, the audio power amplifier is closed before the power supply drops below the normal working voltage of the whole machine, and the POP sound of the loudspeaker is avoided. The utility model only uses the energy storage circuit and the switch circuit in the form of hardware, perfectly solves the POP sound caused by sudden power-off of the product during the working process, greatly reduces the cost, and improves the experience of customers.

Claims

1. A circuit for eliminating a pop-on-power-off (POP) sound of a horn, characterized by comprising: The application relates to a power supply circuit for a loudspeaker. The power supply circuit comprises a storage circuit and a switch circuit, wherein, a first end of the storage circuit is connected with a power supply of the loudspeaker, and a second end of the storage circuit is connected with a first end of the switch circuit; a second end of the switch circuit is connected with the power supply, a third end of the switch circuit is connected with a control end of an audio power amplifier of the loudspeaker, and the third end of the switch circuit is also connected with a controller of the audio power amplifier; when the power supply is normal, the power supply charges the storage circuit, and the switch circuit is in an off state, and the controller controls opening or closing of the audio power amplifier; when the power supply is powered off, the storage circuit is discharged to make the switch circuit conductive, the control end of the audio power amplifier is pulled low, and the audio power amplifier is closed.

2. The circuit for eliminating the pop-on power off sound of a horn according to claim 1, wherein The switch circuit comprises a first switch sub-circuit and a second switch sub-circuit, wherein, a first end of the first switch sub-circuit is connected with the second end of the storage circuit, a second end of the first switch sub-circuit is connected with the power supply, and a third end of the first switch sub-circuit is connected with a first end of the second switch sub-circuit; a second end of the second switch sub-circuit is connected with the control end of the audio power amplifier of the loudspeaker and the controller of the audio power amplifier, and a third end of the second switch sub-circuit is grounded; when the power supply is normal, the first switch sub-circuit and the second switch sub-circuit are both in an off state; when the power supply is powered off, the storage circuit is discharged to make the first switch sub-circuit conductive, and the second switch sub-circuit is conductive to pull the control end of the audio power amplifier low, and the audio power amplifier is closed.

3. The circuit for eliminating the pop-on power off sound of a horn according to claim 2, wherein The first switch sub-circuit comprises a first triode and a third resistor, wherein, an emitter of the first triode is connected with the second end of the storage circuit, a base of the first triode is connected with the power supply through the third resistor, and a collector of the first triode is connected with the first end of the second switch sub-circuit; when the power supply is normal, the first triode is cut off; when the power supply is powered off, the storage circuit is discharged to make the first triode conductive.

4. The circuit for eliminating the pop-on power off sound of a horn according to claim 3, wherein The second switch sub-circuit comprises a second triode and a fourth resistor, wherein, a base of the second triode is connected with the third end of the first switch sub-circuit through the fourth resistor, an emitter of the second triode is grounded, and a collector of the second triode is connected with the control end of the audio power amplifier of the loudspeaker and the controller of the audio power amplifier; when the power supply is normal, the second triode is cut off; when the power supply is powered off, the first triode is conductive, and the second triode is conductive.

5. The circuit of claim 1, wherein, The storage circuit comprises a voltage dividing circuit, an anti-reverse circuit and a storage capacitor, wherein, a first end of the voltage dividing circuit is connected with the power supply of the loudspeaker, a second end of the voltage dividing circuit is connected with a first end of the anti-reverse circuit, and the second end of the voltage dividing circuit is grounded; a second end of the anti-reverse circuit is connected with a first end of the storage capacitor and a first end of the switch circuit; a second end of the storage capacitor is grounded.

6. The circuit for eliminating the pop-on power off sound of a horn according to claim 5, wherein The voltage dividing circuit comprises a first resistor and a second resistor, wherein, The first end of the first resistor is connected with a power supply of the loudspeaker, and the second end of the first resistor is connected with the first end of the second resistor and the first end of the anti-reverse circuit. The second end of the second resistor is grounded.

7. The circuit for eliminating the pop-on power off sound of a horn according to claim 6, wherein The anti-reverse circuit comprises a diode, wherein The anode of the diode is connected with the second end of the voltage dividing circuit, and the cathode of the diode is connected with the first end of the energy storage capacitor and the first end of the switching circuit.

8. The circuit for eliminating the pop-on power off sound of a horn according to claim 1, wherein Further comprising: a filter circuit, wherein The first end of the filter circuit is connected with the third end of the switching circuit, and the second end of the filter circuit is grounded. The filter circuit is used for filtering out the clutter on the line.

9. The circuit for eliminating the POP sound of the loudspeaker according to claim 1, wherein The third end of the switching circuit is connected with a controller of the audio power amplifier through a fifth resistor.

10. An audio device, comprising: It comprises: an audio power amplifier and the circuit for eliminating the POP sound of the loudspeaker according to any one of claims 1-9.

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