Protection circuit of audio equipment and audio equipment

Abstract

The utility model relates to the technical field of audio, in particular to a protection circuit of audio equipment and the audio equipment. The protection circuit of the audio equipment comprises the boosted circuit, the overvoltage protection circuit and the power amplifier module, the overvoltage protection circuit is arranged between the boosted circuit and the power amplifier module, overvoltage protection is carried out on a power amplifier, the power amplifier is prevented from being damaged due to overvoltage, and compared with the overvoltage protection circuit arranged in the power amplifier, the protection circuit has the advantages that the reliability is high; the overvoltage protection circuit arranged at the power supply end of the power amplifier is higher in temperature resistance and current bearing capacity and is more stable than an overvoltage protection circuit arranged in the power amplifier, the protection circuit of the audio equipment is simple in structure, the selectivity of the power amplifier is more, various alternative schemes are provided, and the protection circuit is suitable for popularization and application. While the cost of the audio equipment is reduced, the reliability and the stability of the audio equipment are ensured.

Description

Technical Field

[0001] The utility model relates to the technical field of audio equipment, in particular to a protection circuit of an audio equipment and an audio equipment. Background Art

[0002] Audio equipment is a series of electronic devices used to record, edit, amplify, play and process audio signals. Due to fluctuations in the input voltage of the audio equipment, the power amplifier in the audio equipment may be damaged, causing the audio equipment to fail. In the prior art, in order to prevent the power amplifier from being damaged due to overvoltage, an overvoltage protection function is set inside the power amplifier. However, this power amplifier is expensive and has poor substitutability, which greatly increases the cost of the audio equipment. Utility Model Content

[0003] The embodiments of the utility model provide a protection circuit of an audio device and an audio device, so as to solve the problem of increasing the cost of the audio device caused by using a power amplifier with an overvoltage protection function for overvoltage protection in the prior art.

[0004] In a first aspect, the utility model provides a protection circuit for an audio device, comprising: a boost circuit, an overvoltage protection circuit and a power amplifier module, wherein the input end of the boost circuit is used to connect to a power supply, the output end of the boost circuit is connected to the input end of the overvoltage protection circuit, the output end of the overvoltage protection circuit is connected to the power supply end of the power amplifier module, the input end of the power amplifier module is used to input an audio signal, and the output end of the power amplifier module is used to connect to a speaker in the audio device.

[0005] In one embodiment, the protection circuit of the audio device also includes: a voltage regulating circuit, wherein the input end of the voltage regulating circuit is used to input an audio signal, the output end of the voltage regulating circuit is connected to the input end of the power amplifier module, the control end of the voltage regulating circuit is electrically connected to the boost circuit, and the voltage regulating circuit is used to adjust the voltage output by the boost circuit according to the signal at its input end.

[0006] In one embodiment, the voltage regulation circuit includes: a Bluetooth module, a second switching circuit and a voltage divider circuit, the audio signal input end of the Bluetooth module is used to input an audio signal, the audio signal output end of the Bluetooth module is connected to the input end of the power amplifier module, the control signal output end of the Bluetooth module is connected to the control end of the second switching circuit, the input end of the second switching circuit is connected to the first output end of the voltage divider circuit, the output end of the second switching circuit is grounded, the first input end of the voltage divider circuit is connected to the output end of the boost circuit, the second input end of the voltage divider circuit is connected to the voltage feedback end of the boost circuit, and the second output end of the voltage divider circuit is grounded.

[0007] In one implementation, the voltage regulating circuit further includes: a second voltage stabilizing circuit, wherein an input end of the second voltage stabilizing circuit is connected to a voltage feedback end of the boost circuit, and an output end of the second voltage stabilizing circuit is grounded.

[0008] In one embodiment, the voltage divider circuit includes: a first resistor, a second resistor and a third resistor, one end of the first resistor is connected to the output end of the boost circuit, the other end of the first resistor is connected to the voltage feedback end of the boost circuit, the other end of the first resistor is connected to one end of the second resistor, one end of the second resistor is grounded, one end of the second resistor is connected to one end of the third resistor, and one end of the third resistor is connected to the control end of the second switching circuit.

[0009] In one embodiment, the boost circuit includes an overcurrent protection circuit, an input end of the overcurrent protection circuit is used to connect to a power supply, and an output end of the overcurrent protection circuit is electrically connected to the overvoltage protection circuit.

[0010] In one embodiment, the overcurrent protection circuit includes: a third switch circuit, a current detection circuit and a boost controller, the input end of the third switch circuit is used to connect to a power supply, the first output end of the third switch circuit is electrically connected to the overvoltage protection circuit, the control end of the third switch circuit is connected to the control signal output end of the boost controller, the second output end of the third switch circuit is connected to the input end of the current detection circuit, the output end of the current detection circuit is grounded, the input end of the current detection circuit is connected to the current detection end of the boost controller, and the boost controller is used to control the third switch circuit according to the signal of its current detection end.

[0011] In one embodiment, the overvoltage protection circuit includes: a first switching circuit and a first voltage stabilizing circuit, a voltage stabilizing diode is connected in series in the first voltage stabilizing circuit, the input end of the first switching circuit is connected to the output end of the boost circuit, the output end of the first switching circuit is connected to the power supply end of the power amplifier module, the control end of the first switching circuit is connected to the negative pole of the voltage stabilizing diode, the negative pole of the voltage stabilizing diode is connected to the output end of the boost circuit, and the positive pole of the voltage stabilizing diode is grounded.

[0012] In one embodiment, the first switch circuit includes: a first switch tube, a second switch tube and a voltage-dividing resistor, the input end of the first switch tube is connected to the output end of the boost circuit, the output end of the first switch tube is connected to the power supply end of the power amplifier module, the control end of the first switch tube is connected to the output end of the second switch tube, the output end of the second switch tube is connected to one end of the voltage-dividing resistor, the other end of the voltage-dividing resistor is grounded, the input end of the second switch tube is connected to the output end of the boost circuit, and the control end of the second switch tube is connected to the negative electrode of the voltage-stabilizing tube.

[0013] In a second aspect, this embodiment provides an audio device, comprising a speaker and a protection circuit of the audio device as described in the first aspect and its improvement, wherein the speaker is electrically connected to an output end of the power amplifier module.

[0014] Compared with the prior art, the embodiments of the present invention have the following beneficial effects:

[0015] The protection circuit of the audio device of the present invention comprises: a boost circuit, an overvoltage protection circuit and a power amplifier module. The overvoltage protection circuit is arranged between the boost circuit and the power amplifier module to perform overvoltage protection on the power amplifier to prevent the power amplifier from being damaged due to overvoltage. Compared with the overvoltage protection circuit arranged inside the power amplifier, the overvoltage protection circuit arranged at the power supply end of the power amplifier of the present invention has stronger temperature resistance and current bearing capacity, and is more stable than the overvoltage protection circuit arranged inside the power amplifier. In addition, the protection circuit structure of the audio device of the present invention is simple, the power amplifier has more selectivity, and has multiple alternatives, which reduces the cost of the audio device while ensuring the reliability and stability of the audio device. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions of the embodiments of the utility model, the drawings required for use in the description of the embodiments of the utility model will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0017] Figure 1 It is a schematic diagram of the module structure of a protection circuit of an audio device provided by an embodiment of the utility model;

[0018] Figure 2 It is a schematic diagram of the module structure of a protection circuit of an audio device provided by an embodiment of the utility model;

[0019] Figure 3 It is a schematic diagram of the module structure of a voltage regulating circuit provided in one embodiment of the utility model;

[0020] Figure 4 This is a circuit connection diagram of a voltage regulating circuit provided by an embodiment of the utility model;

[0021] Figure 5 It is a schematic diagram of the module structure of a boost circuit provided by an embodiment of the utility model;

[0022] Figure 6 It is a schematic diagram of the module structure of an overcurrent protection circuit provided by an embodiment of the utility model;

[0023] Figure 7 It is a schematic diagram of the module structure of an overvoltage protection circuit provided by an embodiment of the utility model;

[0024] Figure 8 This is a circuit connection diagram of an overvoltage protection circuit provided by an embodiment of the utility model;

[0025] Among them, 1. boost circuit, 2. overvoltage protection circuit, 3. power amplifier module, 4. power supply, 5. speaker, 6. voltage regulation circuit, 11. overcurrent protection circuit, 21. first switch circuit, 22. first voltage stabilizing circuit, 61. Bluetooth module, 62. second switch circuit, 63. voltage divider circuit, 64. second voltage stabilizing circuit, 111. third switch circuit, 112. current detection circuit, 113. boost controller, 221. voltage regulator. DETAILED DESCRIPTION

[0026] In order to make the technical problems, technical solutions and beneficial effects solved by the utility model more clear, the utility model is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the utility model and are not used to limit the utility model.

[0027] In the description of the present invention, it should be understood that the terms "longitudinal", "radial", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In the description of the present invention, unless otherwise specified, "plurality" means two or more.

[0028] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0029] In order to thoroughly understand the present invention, detailed structures and steps will be presented in the following description to illustrate the technical solution proposed by the present invention. The preferred embodiments of the present invention are described in detail below, but in addition to these detailed descriptions, the present invention may also have other implementations.

[0030] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the disclosure belongs. It will be further understood that the terms used herein should be interpreted as having a meaning consistent with their meaning in the context of this specification and the relevant technology, and will not be interpreted in an idealized or overly formal sense unless explicitly defined as such herein.

[0031] In one embodiment, if Figure 1 As shown, a schematic diagram of the module structure of a protection circuit of an audio device is provided, comprising: a boost circuit 1, an overvoltage protection circuit 2 and a power amplifier module 3, wherein the input end of the boost circuit 1 is used to connect to a power supply 4, the output end of the boost circuit 1 is connected to the input end of the overvoltage protection circuit 2, the output end of the overvoltage protection circuit 2 is connected to the power supply end of the power amplifier module 3, the input end of the power amplifier module 3 is used to input an audio signal, and the output end of the power amplifier module 3 is used to connect to a speaker 5 in the audio device.

[0032] Specifically, the input end of the boost circuit 1 can be connected to a power socket or a power battery. The boost circuit 1 is used to increase the voltage at its input end and provide a power supply voltage to the power amplifier module 3 through the overvoltage protection circuit 2; the overvoltage protection circuit 2 can be any type of overvoltage protection circuit 2, and the standard value of the overvoltage protection circuit 2 can be set according to the actual application situation. When the voltage output by the boost circuit 1 exceeds the standard value of the overvoltage protection circuit 2, the overvoltage protection circuit 2 is turned off, and the power amplifier module 3 is protected from overvoltage.

[0033] The working process of the protection circuit of the above-mentioned audio device is as follows: the signal output by the power supply 4 is boosted by the boost circuit 1, and the boosted signal flows to the power supply end of the power amplifier module 3 through the overvoltage protection circuit 2. The power amplifier module 3 amplifies the audio signal input to its input end so that the speaker 5 can make sound.

[0034] The protection circuit of the audio device of this embodiment is provided with an overvoltage protection circuit 2 between the boost circuit 1 and the power amplifier module 3 to perform overvoltage protection on the power amplifier to prevent the power amplifier from being damaged due to overvoltage. Compared with the overvoltage protection circuit 2 provided inside the power amplifier, the overvoltage protection circuit 2 provided at the power supply end of the power amplifier of the utility model has stronger temperature resistance and current bearing capacity, and is more stable than the overvoltage protection circuit 2 provided inside the power amplifier. In addition, the protection circuit structure of the audio device of the utility model is simple, the power amplifier has more selectivity, and has multiple alternatives, which reduces the cost of the audio device while ensuring the reliability and stability of the audio device.

[0035] In one embodiment, if Figure 2 As shown, a module structure diagram of a protection circuit of an audio device is provided. Figure 1 On the basis of the protection circuit of the audio device shown, the protection circuit of the audio device also includes: a voltage regulating circuit 6, the input end of the voltage regulating circuit 6 is used to input the audio signal, the output end of the voltage regulating circuit 6 is connected to the input end of the power amplifier module 3, the control end of the voltage regulating circuit 6 is electrically connected to the boost circuit 1, and the voltage regulating circuit 6 is used to adjust the voltage output by the boost circuit 1 according to the signal at its input end.

[0036] Specifically, the voltage regulation circuit 6 should include a Bluetooth module or other control module. The Bluetooth module supplies power to the power amplifier module 3 on demand according to the amplitude of the audio signal at the input end. If a high-amplitude audio signal is detected, the output end of the boost circuit 1 is controlled to output a high voltage to the power amplifier module 3 through the overvoltage protection circuit 2; if a low-amplitude audio signal is detected, the output end of the boost circuit 1 is controlled to output a low voltage to the power amplifier module 3 through the overvoltage protection circuit 2.

[0037] The working process of the protection circuit of the above audio device is as follows: the voltage regulating circuit 6 detects the audio signal, processes the audio signal and outputs it, and controls the voltage at the output end of the boost circuit 1 according to the amplitude of the audio signal to be output.

[0038] The protection circuit of the audio device of this embodiment is provided with a voltage regulating circuit 6. The voltage regulating circuit 6 regulates the signal at the output end of the boost circuit 1 according to the amplitude of the audio signal, thereby preventing the boost circuit 1 from always supplying power to the power amplifier module 3 with the maximum supply voltage, reducing the energy consumption of the power amplifier module 3, maximizing the efficiency of the power amplifier module 3, and greatly improving the overall efficiency of the circuit.

[0039] like Figure 3 As shown, a schematic diagram of the module structure of a voltage regulating circuit 6 is provided.

[0040] In one embodiment, if Figure 5As shown in the above Figure 2 On the basis of the protection circuit of the audio device shown, the voltage regulating circuit 6 includes: a Bluetooth module 61, a second switching circuit 62 and a voltage divider circuit 63, the audio signal input end of the Bluetooth module 61 is used to input an audio signal, the audio signal output end of the Bluetooth module 61 is connected to the input end of the power amplifier module 3, the control signal output end of the Bluetooth module 61 is connected to the control end of the second switching circuit 62, the input end of the second switching circuit 62 is connected to the first output end of the voltage divider circuit 63, the output end of the second switching circuit 62 is grounded, the first input end of the voltage divider circuit 63 is connected to the output end of the boost circuit 1, the second input end of the voltage divider circuit 63 is connected to the voltage feedback end of the boost circuit 1, and the second output end of the voltage divider circuit 63 is grounded.

[0041] Specifically, the Bluetooth module 61 may receive audio signals by wireless reception, and transmit the audio signals through a wireless receiver. The receiving unit may receive audio signals by wired reception, and transmit the audio signals through a data line. Preferably, the receiving unit receives audio signals by wireless reception.

[0042] The second switch circuit 62 can be any type of switch circuit. The second switch circuit 62 can have the same structure as the first switch circuit 21, or it can have a different structure from the first switch circuit 21. Preferably, a switch tube is provided in the second switch circuit 62 to control the conduction and disconnection of the second switch circuit 62.

[0043] The working process of the protection circuit of the above-mentioned audio device is as follows: the Bluetooth module 61 obtains the audio signal, processes the audio signal and outputs it, and controls the second switch circuit 62 according to the amplitude of the audio signal to be output. When the second switch circuit 62 is turned on, the first output end of the voltage divider circuit 63 is grounded through the second switch circuit 62, and the current flowing through the branch where the first output end of the voltage divider circuit 63 is located reaches the maximum value, and the voltage signal at the output end of the boost circuit 1 is the maximum value; when the second switch circuit 62 is turned off, the branch where the second output end of the voltage divider circuit 63 is located is turned off, the current is zero, and the voltage signal at the output end of the boost circuit 1 is the minimum value.

[0044] The protection circuit of the audio device of this embodiment is provided with a Bluetooth module 61, a second switch circuit 62 and a voltage divider circuit 63 in the voltage regulating circuit 6. The second switch circuit 62 is controlled by the pulse signal output by the Bluetooth module 61, so that the voltage signal at the output end of the boost circuit 1 can be controlled. The structure is simple and the cost of the circuit is greatly reduced.

[0045] In one embodiment, if Figure 3As shown, based on the above embodiment, the voltage regulating circuit 6 further includes: a second voltage stabilizing circuit 64, the input end of the second voltage stabilizing circuit 64 is connected to the voltage feedback end of the boost circuit 1, and the output end of the second voltage stabilizing circuit 64 is grounded.

[0046] It is understandable that a capacitor is provided in the second voltage stabilizing circuit 64 , and the capacitor is used to buffer the voltage feedback terminal of the boost circuit 1 .

[0047] The working process of the protection circuit of the above audio device is as follows: when the voltage regulating circuit 6 regulates the signal at the output end of the boosting circuit 1 , the second voltage stabilizing circuit 64 is used to stabilize the voltage feedback end of the boosting circuit 1 .

[0048] The protection circuit of the audio device of this embodiment is provided with a voltage stabilizing circuit in the voltage regulating circuit 6 to stabilize the voltage at the voltage feedback end of the boost circuit 1, thereby preventing the voltage at the voltage feedback end of the boost circuit 1 from becoming unstable due to the conduction and disconnection of the second switch circuit 62, thereby ensuring the stability and reliability of the circuit.

[0049] In one embodiment, if Figure 4 As shown, a circuit connection diagram of a voltage regulating circuit 6 is provided. Figure 3 On the basis of the protection circuit of the audio device shown in the figure, the voltage divider circuit 63 includes: a first resistor R2, a second resistor R1 and a third resistor R3, one end of the first resistor R2 is connected to the output end of the boost circuit 1, the other end of the first resistor R2 is connected to the voltage feedback end of the boost circuit 1, the other end of the first resistor R2 is connected to one end of the second resistor R1, one end of the second resistor R1 is grounded, one end of the second resistor R1 is connected to one end of the third resistor R3, and one end of the third resistor R3 is connected to the control end of the second switch circuit 62.

[0050] The working process of the protection circuit of the above-mentioned audio device is as follows: the switch tube Q11 in the second switch circuit 62 can control the on and off of part of the circuit between the Bluetooth module 61 and the boost circuit 1. When the switch tube Q11 is turned on, the third resistor R3 and the second resistor R1 form a parallel circuit, and the signal output by the Bluetooth module 61 can reach the voltage feedback end through the resistor R6 and the parallel circuit; when the switch tube is turned off, the signal output by the Bluetooth module 61 can reach the voltage feedback end through the resistor R6 and the second resistor R1.

[0051] The protection circuit of the audio device of this embodiment uses multiple resistors to form a voltage divider circuit 63. The first resistor is connected to the output end and the voltage feedback end of the boost circuit 1. A voltage drop will be generated after the voltage passes through the first resistor R2, which can prevent the circuit from being damaged due to excessive voltage.

[0052] In one embodiment, if Figure 5As shown, a schematic diagram of the module structure of a boost circuit 1 is provided. Figure 1 On the basis of the protection circuit of the audio device shown, the boost circuit 1 includes an overcurrent protection circuit 11, the input end of the overcurrent protection circuit 11 is used to connect to the power supply 4, and the output end of the overcurrent protection circuit 11 is electrically connected to the overvoltage protection circuit 2.

[0053] Specifically, the input end of the overcurrent protection circuit 11 can be connected to a power socket or a power battery. The overcurrent protection circuit 11 can be any type of overcurrent protection circuit 11. The standard value of the overcurrent protection circuit 11 can be set according to actual application conditions. When the detected current value is greater than the preset standard value, the overcurrent protection circuit 11 is turned off to protect the power amplifier module 3.

[0054] The working process of the protection circuit of the above audio device is as follows: the signal output by the power supply 4 is boosted by the boost circuit 1 , and the overcurrent protection circuit 11 is used to protect the power amplifier module 3 from overcurrent.

[0055] The protection circuit of the audio device of this embodiment is provided with an overcurrent protection circuit 11 in the boost circuit 1. While providing overcurrent protection to the power amplifier module 3, the boost circuit 1 can also be protected to avoid damage to the boost circuit 1 when a short circuit occurs in the power amplifier module 3.

[0056] In one embodiment, if Figure 6 As shown, a schematic diagram of the module structure of an overcurrent protection circuit 11 is provided. Figure 5 On the basis of the protection circuit of the audio device shown in the figure, the overcurrent protection circuit 11 includes: a third switch circuit 111, a current detection circuit 112 and a boost controller 113, the input end of the third switch circuit 111 is used to connect to the power supply 4, the first output end of the third switch circuit 111 is electrically connected to the overvoltage protection circuit 2, the control end of the third switch circuit 111 is connected to the control signal output end of the boost controller 113, the second output end of the third switch circuit 111 is connected to the input end of the current detection circuit 112, the output end of the current detection circuit 112 is grounded, the input end of the current detection circuit 112 is connected to the current detection end of the boost controller 113, and the boost controller 113 is used to control the third switch circuit 111 according to the signal of its current detection end.

[0057] It is understandable that the third switch circuit 111 can be any type of switch circuit. The third switch circuit 111 can be the same as the first switch circuit 21 and / or the second switch circuit 62, or the third switch circuit 111 can be different from the first switch circuit 21 and / or the second switch circuit 62. Preferably, the third switch circuit 111 is two switch tubes connected in series.

[0058] The boost controller 113 may be any type of boost controller 113. Preferably, the boost controller 113 is of MP3910. Specifically, the boost controller 113 determines whether the signal input to the power amplifier module 3 exceeds the maximum current by collecting the voltage value of the input end of the current detection circuit 112. A resistor should be provided in the current detection circuit 112, and the maximum current at the output end of the boost circuit 1 is set by setting the parameters of the resistor.

[0059] The working process of the protection circuit of the above-mentioned audio device is: the boost controller 113 obtains the current signal at the output end of the boost circuit 1 through the current detection circuit 112. If the current signal exceeds the preset maximum current signal, the control signal output end of the boost controller 113 outputs a shutdown signal of the third switch circuit 111, controls the third switch circuit 111 to be shut down, and the power supply 4 signal cannot be output through the third switch circuit 111.

[0060] The protection circuit of the audio device of this embodiment is provided with a third switch circuit 111, a current detection circuit 112 and a boost controller 113 in the overcurrent protection circuit 11 to perform overcurrent protection on the power amplifier module 3. The third switch circuit 111 can quickly cut off the power supply of the power amplifier module 3 to reduce the risk of damage to the power amplifier module 3, and the third switch circuit 111 is used for isolation to increase the safety and reliability of the circuit.

[0061] In one embodiment, if Figure 7 As shown, a schematic diagram of the module structure of an overvoltage protection circuit 2 is provided. Figure 1 On the basis of the protection circuit of the audio device shown in the figure, the overvoltage protection circuit 2 includes: a first switching circuit 21 and a first voltage stabilizing circuit 22, a voltage stabilizing tube 221 is serially connected in the first voltage stabilizing circuit 22, the input end of the first switching circuit 21 is connected to the output end of the boost circuit 1, the output end of the first switching circuit 21 is connected to the power supply end of the power amplifier module 3, the control end of the first switching circuit 21 is connected to the negative pole of the voltage stabilizing tube 221, the negative pole of the voltage stabilizing tube 221 is connected to the output end of the boost circuit 1, and the positive pole of the voltage stabilizing tube 221 is grounded.

[0062] It is understandable that the first switch circuit 21 can be any switch circuit. A switch tube can be provided in the first switch circuit 21 to control the on and off of the first switch circuit 21 by using the switch tube; an optocoupler can be provided in the first switch circuit 21 to control the on and off of the first switch circuit 21 by using the optocoupler; a relay can be provided in the first switch circuit 21 to control the on and off of the first switch circuit 21 by using the relay. Preferably, a switch tube is provided in the first switch circuit 21 to control the on and off of the first switch circuit 21. One switch control device can be provided in the first switch circuit 21, or multiple switch control devices can be provided in the first switch circuit 21. The on and off of the first switch circuit 21 can be controlled by sequentially turning on the multiple switch control devices.

[0063] Only a voltage regulator tube 221 may be provided in the first voltage regulator circuit 22, and electronic devices such as resistors may also be used in the first voltage regulator circuit 22 to limit the current of the voltage regulator tube 221. Voltage regulator tubes 221 of different specifications may be selected according to actual application conditions. Preferably, the conduction voltage of the voltage regulator tube 221 is 25 volts. Furthermore, the voltage regulator tube 221 of this embodiment is a recoverable voltage regulator tube 221. When the voltage regulator tube 221 is broken down, if the voltage at the negative terminal of the voltage regulator tube 221 is less than the conduction voltage of the voltage regulator tube 221, the voltage regulator tube 221 can be restored to a voltage-stabilizing state.

[0064] The working process of the protection circuit of the above audio device is as follows: the signal at the output end of the boost circuit 1 flows to the negative electrode of the voltage regulator tube 221. If the signal is not less than the conduction voltage of the voltage regulator tube 221, the voltage regulator tube 221 breaks down, and the signal at the control end of the first switch circuit 21 is pulled down. The first switch circuit 21 is turned off, and the signal at the output end of the boost circuit 1 cannot flow to the power amplifier module 3 through the first switch circuit 21 until the signal at the output end of the boost circuit 1 is less than the conduction voltage of the voltage regulator tube 221; if the signal at the output end of the boost circuit 1 is less than the conduction voltage of the voltage regulator tube 221, the voltage regulator tube 221 is in a voltage-stabilizing state, the signal at the control end of the first switch circuit 21 is a high-level signal, the first switch circuit 21 is turned on, and the signal at the output end of the boost circuit 1 flows to the power amplifier module 3 through the first switch circuit 21.

[0065] The protection circuit of the audio device of this embodiment is provided with a first switch circuit 21 and a voltage stabilizing circuit in the overvoltage protection circuit 2. The voltage stabilizing diode 221 in the voltage stabilizing circuit has a fast response speed and can effectively prevent instantaneous spike voltage from causing damage to the circuit. The recoverable voltage stabilizing diode 221 is used to enable the circuit to return to a normal working state after the voltage returns to normal, thereby reducing the circuit cost and ensuring the stable operation of the circuit.

[0066] In one embodiment, if Figure 8 As shown, a circuit connection diagram of an overvoltage protection circuit 2 is provided. Figure 7On the basis of the protection circuit of the audio device shown in the figure, the first switch circuit 21 includes; a first switch tube Q3, a second switch tube Q101 and a voltage-dividing resistor R129, the input end of the first switch tube Q3 is connected to the output end of the boost circuit 1, the output end of the first switch tube Q3 is connected to the power supply end of the power amplifier module 3, the control end of the first switch tube Q3 is connected to the output end of the second switch tube Q101, the output end of the second switch tube Q101 is connected to one end of the voltage-dividing resistor R129, the other end of the voltage-dividing resistor R129 is grounded, the input end of the second switch tube Q101 is connected to the output end of the boost circuit 1, and the control end of the second switch tube Q101 is connected to the negative electrode of the voltage-stabilizing tube 221.

[0067] The first switch tube Q3 can be any switch tube, the first switch tube Q3 can be a triode, the first switch tube Q3 can also be a MOS tube, the first switch tube Q3 can also be a field effect tube, the second switch tube Q101 can be the same as the first switch tube Q3, the second switch tube Q101 can also be different from the first switch tube Q3, preferably, as Figure 7 As shown, the second switch tube Q101 is a triode, and the first switch tube Q3 is a MOS tube. Further, a capacitor can be set in the circuit to filter the signal, and a resistor can be set to protect the switch tube.

[0068] The working process of the protection circuit of the above audio device is as follows: when the voltage at the output end of the boost circuit 1 is higher than the conduction voltage of the voltage regulator tube 221, the voltage regulator tube 221 breaks down, and the second switch tube Q101 is turned on. After the second switch tube Q101 is turned on, the voltage at the control end of the first switch tube Q3 is pulled up, and the first switch tube Q3 is turned off. The signal at the output end of the boost circuit 1 cannot be output through the first switch tube Q3. When the voltage at the output end of the boost circuit 1 is less than the conduction voltage of the voltage regulator tube 221, the voltage regulator tube 221 recovers, the second switch tube Q101 is turned off, the first switch tube Q3 is turned on, and the signal at the output end of the boost circuit 1 is output through the second switch tube Q101.

[0069] The protection circuit of the audio device of this embodiment is controlled by a switch tube in the first switch circuit 21. The switch tube can respond quickly and perform electrical isolation, thereby enhancing the safety and reliability of the circuit.

[0070] In one embodiment, an audio device is provided. The audio device includes a speaker 5 and the protection circuit of the audio device mentioned in any of the above embodiments. The speaker 5 is electrically connected to the output end of the power amplifier module 3 .

[0071] The embodiments described above are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention, and should be included in the protection scope of the present invention.

Claims

1. A protection circuit for an audio device, characterized in that: include: A boost circuit, an overvoltage protection circuit and a power amplifier module, wherein the input end of the boost circuit is used to connect to a power supply, the output end of the boost circuit is connected to the input end of the overvoltage protection circuit, the output end of the overvoltage protection circuit is connected to the power supply end of the power amplifier module, the input end of the power amplifier module is used to input an audio signal, and the output end of the power amplifier module is used to connect to a speaker in the audio device.

2. The protection circuit of the audio device according to claim 1, characterized in that: The protection circuit of the audio device also includes: a voltage regulating circuit, the input end of the voltage regulating circuit is used to input an audio signal, the output end of the voltage regulating circuit is connected to the input end of the power amplifier module, the control end of the voltage regulating circuit is electrically connected to the boost circuit, and the voltage regulating circuit is used to adjust the voltage output by the boost circuit according to the signal at its input end.

3. The protection circuit of the audio device according to claim 2, characterized in that: The voltage regulation circuit includes: a Bluetooth module, a second switch circuit and a voltage divider circuit, the audio signal input end of the Bluetooth module is used to input an audio signal, the audio signal output end of the Bluetooth module is connected to the input end of the power amplifier module, the control signal output end of the Bluetooth module is connected to the control end of the second switch circuit, the input end of the second switch circuit is connected to the first output end of the voltage divider circuit, the output end of the second switch circuit is grounded, the first input end of the voltage divider circuit is connected to the output end of the boost circuit, the second input end of the voltage divider circuit is connected to the voltage feedback end of the boost circuit, and the second output end of the voltage divider circuit is grounded.

4. The protection circuit of the audio device according to claim 3, characterized in that: The voltage regulating circuit further includes: a second voltage stabilizing circuit, wherein an input end of the second voltage stabilizing circuit is connected to a voltage feedback end of the boost circuit, and an output end of the second voltage stabilizing circuit is grounded.

5. The protection circuit of the audio device according to claim 4, characterized in that: The voltage divider circuit includes: a first resistor, a second resistor and a third resistor, one end of the first resistor is connected to the output end of the boost circuit, the other end of the first resistor is connected to the voltage feedback end of the boost circuit, the other end of the first resistor is connected to one end of the second resistor, one end of the second resistor is grounded, one end of the second resistor is connected to one end of the third resistor, and one end of the third resistor is connected to the control end of the second switch circuit.

6. The protection circuit of the audio device according to claim 1, characterized in that: The boost circuit comprises an overcurrent protection circuit, an input end of the overcurrent protection circuit is used to connect to a power source, and an output end of the overcurrent protection circuit is electrically connected to the overvoltage protection circuit.

7. The protection circuit of the audio device according to claim 6, characterized in that: The overcurrent protection circuit includes: a third switch circuit, a current detection circuit and a boost controller, the input end of the third switch circuit is used to connect to a power supply, the first output end of the third switch circuit is electrically connected to the overvoltage protection circuit, the control end of the third switch circuit is connected to the control signal output end of the boost controller, the second output end of the third switch circuit is connected to the input end of the current detection circuit, the output end of the current detection circuit is grounded, the input end of the current detection circuit is connected to the current detection end of the boost controller, and the boost controller is used to control the third switch circuit according to the signal of its current detection end.

8. The protection circuit of the audio device according to claim 1, characterized in that: The overvoltage protection circuit includes: a first switching circuit and a first voltage stabilizing circuit, a voltage stabilizing tube is connected in series in the first voltage stabilizing circuit, an input end of the first switching circuit is connected to an output end of the boost circuit, an output end of the first switching circuit is connected to a power supply end of the power amplifier module, a control end of the first switching circuit is connected to a negative electrode of the voltage stabilizing tube, a negative electrode of the voltage stabilizing tube is connected to an output end of the boost circuit, and a positive electrode of the voltage stabilizing tube is grounded.

9. The protection circuit of the audio device according to claim 8, characterized in that: The first switch circuit includes: a first switch tube, a second switch tube and a voltage-dividing resistor, the input end of the first switch tube is connected to the output end of the boost circuit, the output end of the first switch tube is connected to the power supply end of the power amplifier module, the control end of the first switch tube is connected to the output end of the second switch tube, the output end of the second switch tube is connected to one end of the voltage-dividing resistor, the other end of the voltage-dividing resistor is grounded, the input end of the second switch tube is connected to the output end of the boost circuit, and the control end of the second switch tube is connected to the negative electrode of the voltage-stabilizing tube.

10. An audio device, characterized in that: The audio device comprises a speaker and the protection circuit of the audio device according to any one of claims 1 to 9, and the speaker is electrically connected to the output end of the power amplifier module.

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