Amplifier protection circuit and electronic sound box

Abstract

The embodiment of the utility model provides an amplifier protection circuit and an electronic loudspeaker box. The amplifier protection circuit comprises a negative temperature coefficient thermistor unit; a main control unit, an amplifier chip and a loudspeaker; the negative temperature coefficient thermistor unit comprises a negative temperature coefficient thermistor, a power supply and a pull-up resistor, the negative temperature coefficient thermistor is arranged at a heating part of the amplifier chip, and the negative temperature coefficient thermistor unit is used for measuring the temperature of the amplifier chip; when the temperature of the amplifier chip is greater than a preset value, a level signal is sent to the main control unit; the main control unit is electrically connected with the amplifier chip and used for adjusting the power of the amplifier chip after receiving the level signal, and the amplifier chip is electrically connected with the loudspeaker unit. According to the amplifier protection circuit provided by the invention, the working stability of the amplifier can be ensured, a loudspeaker is driven to achieve the optimal sound effect, the electrical performance, reliability and safety of a product are effectively improved, and the service life of the product is effectively prolonged.

Description

Technical Field

[0001] The present application belongs to the field of electronic equipment, and in particular, relates to an amplifier protection circuit and an electronic speaker. Background Art

[0002] At present, in order to achieve greater progress in sound quality and appearance design, many audio electronic products generally adopt compact sealed cabinets and miniaturized designs. However, this trend has caused a serious problem: the heat generated by the power amplifier is difficult to dissipate effectively in the sealed cabinet, causing the temperature to gradually rise. This phenomenon may cause a variety of problems, including over-temperature protection of the amplifier chip, and even short circuits causing fires, which in turn bring potential safety hazards to the product.

[0003] In the past, traditional high-power audio and electronic products usually use heat sink devices and surrounding air vents to ensure that the heat around the heating device can be smoothly dissipated. However, due to the increasingly stringent market requirements for the sealing, miniaturization and even 7-level waterproof functions of the product box, this has led to an insurmountable technical bottleneck: the heat energy in the product box cannot be effectively discharged, and the amplifier temperature gradually rises, which may lead to safety problems such as over-temperature protection and fire. This application provides a new protection circuit to solve the above problems. Utility Model Content

[0004] A first aspect of an embodiment of the present application provides an amplifier protection circuit, comprising: a negative temperature coefficient thermistor unit; a main control unit, an amplifier chip, and a speaker;

[0005] The negative temperature coefficient thermistor unit comprises: a negative temperature coefficient thermistor, a power supply and a pull-up resistor, the power supply is electrically connected to one end of the pull-up resistor, the other end of the pull-up resistor is connected to the main control unit in parallel with the negative temperature coefficient thermistor, one end of the negative temperature coefficient thermistor is grounded, the other end of the negative temperature coefficient thermistor is connected to the main control unit in parallel with the pull-up resistor, the negative temperature coefficient thermistor is arranged at the heating part of the amplifier chip, and the negative temperature coefficient thermistor unit is used to measure the temperature of the amplifier chip, and send a level signal to the main control unit when the temperature of the amplifier chip is greater than a preset value;

[0006] The main control unit is electrically connected to the amplifier chip and is used to adjust the power of the amplifier chip after receiving the level signal. The amplifier chip is electrically connected to the speaker.

[0007] Based on the amplifier protection circuit provided in the first aspect of the embodiment of the present application, optionally, the negative temperature coefficient thermistor is 10 kilo-ohms and the pull-up resistor is 10 kilo-ohms.

[0008] Based on the amplifier protection circuit provided in the first aspect of the embodiment of the present application, optionally, the power supply voltage is 3.3 volts.

[0009] Based on the amplifier protection circuit provided in the first aspect of the embodiment of the present application, optionally, the main control unit is a central processing unit or a digital signal processing unit.

[0010] Based on the amplifier protection circuit provided in the first aspect of the embodiment of the present application, optionally, the amplifier chip and the main control unit transmit signals via a built-in audio bus of the integrated circuit.

[0011] Based on the amplifier protection circuit provided in the first aspect of the embodiment of the present application, optionally, the main control unit is used to send a communication instruction to the amplifier chip through a bidirectional two-wire synchronous serial bus when the temperature of the amplifier chip is greater than a preset value, so as to reduce the power of the amplifier chip.

[0012] Based on the amplifier protection circuit provided in the first aspect of the embodiment of the present application, optionally, the amplifier chip supports a gain adjustment range from 0 to 36 decibels.

[0013] A second aspect of the embodiments of the present application provides an electronic speaker, characterized in that the electronic speaker comprises the amplifier protection circuit described in any one of the first aspect of the embodiments of the present application.

[0014] The electronic speaker provided in the second aspect of the embodiment of the present application is optionally characterized in that the electronic speaker is a Bluetooth speaker.

[0015] Based on the electronic speaker provided in the second aspect of the embodiment of the present application, optionally, it is characterized in that the electronic speaker supports a level 7 waterproof function.

[0016] It can be seen from the above technical solutions that the embodiments of the present application have the following advantages: the embodiments of the present application provide an amplifier protection circuit, comprising: a negative temperature coefficient thermistor unit; a main control unit, an amplifier chip, and a speaker; the negative temperature coefficient thermistor unit comprises: a negative temperature coefficient thermistor, a power supply, and a pull-up resistor, the power supply is electrically connected to one end of the pull-up resistor, the other end of the pull-up resistor is connected to the main control unit in parallel with the negative temperature coefficient thermistor, one end of the negative temperature coefficient thermistor is grounded, the other end of the negative temperature coefficient thermistor is connected to the main control unit in parallel with the pull-up resistor, the negative temperature coefficient thermistor is arranged at the heating part of the amplifier chip, the negative temperature coefficient thermistor unit is used to measure the temperature of the amplifier chip, and send a level signal to the main control unit when the temperature of the amplifier chip is greater than a preset value; the main control unit is electrically connected to the amplifier chip, and is used to adjust the power of the amplifier chip after receiving the level signal, and the amplifier chip is electrically connected to the speaker unit. Based on this method, a protection circuit for automatically adjusting the amplifier gain is provided, which is suitable for high-power / high-temperature audio electronic products. By automatically adjusting the amplifier gain, the amplifier chip can automatically adjust the amplifier output power when working in different ambient temperatures, ensuring the working stability of the amplifier, driving the speaker to achieve the best sound effect, and effectively improving the product's electrical performance, reliability, safety and service life; BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings required for use in the embodiments or the prior art descriptions are briefly introduced below. Obviously, the drawings described below are only embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without creative work. It is understood that the drawings provided in this section are only used to better understand the present solution and do not constitute a limitation of the present application.

[0018] Figure 1 A schematic diagram of the structure of the amplifier protection circuit provided by the present application;

[0019] Figure 2 A system block diagram of the amplifier protection circuit provided by the present application;

[0020] Figure 3 A schematic diagram of the electronic speaker provided in this application. DETAILED DESCRIPTION

[0021] In order to enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application are clearly and completely described below. Obviously, the described embodiments are only embodiments of a part of the present application, rather than all embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work should belong to the scope of protection of the present application. At the same time, for the sake of clarity and simplicity, the description of well-known functions and structures is omitted in the following description.

[0022] The terms "first", "second", "third", "fourth", etc. (if any) in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments described herein can be implemented in an order other than that illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0023] At present, in order to achieve greater progress in sound quality and appearance design, many audio electronic products generally adopt compact sealed cabinets and miniaturized designs. However, this trend has caused a serious problem: the heat generated by the power amplifier is difficult to dissipate effectively in the sealed cabinet, causing the temperature to gradually rise. This phenomenon may cause a variety of problems, including over-temperature protection of the amplifier chip, and even short circuits causing fires, which in turn bring potential safety hazards to the product.

[0024] In the past, traditional high-power audio and electronic products usually use heat sinks and surrounding air vents to ensure that the heat around the heating device can be smoothly dissipated. However, due to the increasingly stringent market requirements for the sealing, miniaturization and even 7-level waterproof functions of the product box, this has led to an insurmountable technical bottleneck: the heat energy in the product box cannot be effectively discharged, and the amplifier temperature gradually rises, which may cause safety problems such as over-temperature protection and fire. This application provides a new protection circuit to solve the above problems. Please refer to Figure 1 , a schematic diagram of an amplifier protection circuit provided in the present application includes:

[0025] The system 100 includes a negative temperature coefficient thermistor unit, a main control unit 102 , an amplifier chip 103 and a speaker 104 .

[0026] The negative temperature coefficient thermistor unit includes: a negative temperature coefficient thermistor (NTC, Negative Temperature Coefficient resistor) 1013, a power supply 1011 and a pull-up resistor 1012, the power supply 1011 is electrically connected to one end of the pull-up resistor 1012, the other end of the pull-up resistor 1012 is connected to the main control unit 102 in parallel with the negative temperature coefficient thermistor 1013, one end of the negative temperature coefficient thermistor 1013 is grounded, and the other end of the negative temperature coefficient thermistor 1013 is connected to the main control unit 102 in parallel with the pull-up resistor 1012. The negative temperature coefficient thermistor 1013 is arranged at the heating part of the amplifier chip 103, and the negative temperature coefficient thermistor unit is used to measure the temperature of the amplifier chip 103, and send a level signal to the main control unit 102 when the temperature of the amplifier chip 103 is greater than a preset value. The power supply is used to supply power to the pull-up resistor and the negative temperature coefficient thermistor 1013, so that they can send a level signal to the main control unit 102 when the temperature is high to prompt that the temperature is out of range.

[0027] The pull-up resistor and the NTC resistor together form a voltage divider circuit. The pull-up resistor is connected to the system power supply VCC, and the NTC resistor is connected to the ground (GND). According to the principle of the voltage divider circuit, by measuring the voltage of the NTC resistor, the resistance of the NTC resistor can be derived, and the resistance changes with the ambient temperature. The NTC thermistor is used as a temperature sensor here, and its resistance changes with temperature. Through the voltage divider circuit formed by the pull-up resistor, the system can monitor the resistance change of the NTC resistor and obtain the ambient temperature signal. In general, the role of the pull-up resistor in this circuit is to form a temperature sensor together with the NTC resistor, and convert the temperature information into a voltage signal through the voltage divider circuit for further processing and control by the system. The power supply voltage, the resistance of the pull-up resistor and the resistance of the negative temperature coefficient thermistor can be determined according to the actual situation and are not limited here.

[0028] The main control unit 102 is electrically connected to the amplifier chip 103 and is used to adjust the power of the amplifier chip 103 after receiving the level signal. The amplifier chip 103 is electrically connected to the speaker 104 .

[0029] The main control unit 102 is the central control part of the system, responsible for the coordination and control of the entire system. In the actual implementation process, the main control unit 102 can be a CPU or a DSP, which is not limited here. The main control unit 102 receives a level signal from the NTC temperature control detection unit, which reflects the ambient temperature. After receiving the temperature signal, the main control unit 102 communicates with the amplifier chip 103 through a fast I2C bus communication instruction to adjust the power of the amplifier to adapt to different ambient temperatures.

[0030] The amplifier chip 103 is a component responsible for amplifying the audio signal and is used to drive the speaker to produce sound. The amplifier chip 103 receives the signal from the main control unit by being electrically connected to the main control unit 102. According to the received level signal, the amplifier chip 103 adjusts its power or gain to ensure stable audio output under different ambient temperatures. The amplifier chip 103 is electrically connected to the speaker 104 and transmits the amplified audio signal to the speaker to produce sound.

[0031] The speaker 104 is a device that converts electrical signals into sounds. The speaker 104 receives audio signals from the amplifier by being electrically connected to the amplifier chip 103. The speaker 104 converts the received electrical signals into sounds to achieve audio output.

[0032] Specifically, the signal processing process of this method can refer to Figure 2 , Figure 2 This is a system block diagram of the solution provided in this application. The NTC temperature sensor measures the amplifier temperature through the NTC resistor, and sends a signal to the central processor when the temperature is too high. The central processor interacts with the amplifier through I2S or I2C. When the temperature is too high, the amplifier power is reduced. The amplifier is used to control the speaker volume, thereby completing the control of the device.

[0033] Based on the method, a protection circuit for automatically adjusting the amplifier gain is provided, which is suitable for high-power / high-temperature audio electronic products. By automatically adjusting the amplifier gain, the amplifier chip can automatically adjust the amplifier output power when working in different ambient temperatures, ensuring the working stability of the amplifier and driving the speaker to achieve the best sound effect, effectively improving the product's electrical performance as well as reliability, safety and service life.

[0034] Based on the above Figure 1 Corresponding to the embodiment, optionally, in the implementation process of this solution, the negative temperature coefficient thermistor is 10 kilo ohms, the pull-up resistor is 10k kilo ohms, and the power supply voltage is 3.3 volts, so as to provide an adaptive level signal for the central controller.

[0035] Based on the above Figure 1Corresponding to the embodiment, optionally, the main control unit is a central processing unit (CPU) or a digital signal processing unit (DSP).

[0036] Based on the above Figure 1 In the corresponding embodiment, optionally, the amplifier chip and the main control unit transmit signals via an integrated circuit internal audio bus (I2S). I2S stands for Inter-IC Sound, which is a serial communication protocol for transmitting audio data between integrated circuits. The I2S protocol is generally used to connect audio devices such as digital audio processors, decoders, amplifiers, and digital audio input / output.

[0037] Based on the above Figure 1 Corresponding to the embodiment, optionally, the main control unit is used to send a communication instruction to the amplifier chip through a bidirectional two-wire synchronous serial bus (I2C) when the temperature of the amplifier chip is greater than a preset value, so as to reduce the power of the amplifier chip.

[0038] Based on the above Figure 1 Corresponding to the embodiment, optionally, the amplifier chip supports a gain adjustment range from 0 to 36 decibels.

[0039] Based on the above Figure 1 Corresponding to the embodiment, optionally, the present application further provides an electronic speaker, and the specific electronic speaker can be as follows Figure 3 As shown, the electronic speaker is installed with Figure 1 The amplifier protection circuit according to any one of the embodiments.

[0040] Optionally, the electronic speaker is a Bluetooth speaker.

[0041] Optionally, the electronic speaker supports level 7 waterproof function.

[0042] In the several embodiments provided in the present application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic, for example, the equivalent transformation of the circuit, the division of the unit, is only a logical function division, and there may be other division methods in actual implementation, for example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point, the mutual coupling or direct coupling or communication connection shown or discussed can be an indirect coupling or communication connection through some interfaces, devices or units, which can be electrical, mechanical or other forms.

[0043] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple units. Some or all of the units may be selected according to actual needs to achieve the purpose of the present embodiment.

[0044] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0045] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modification, equivalent substitution or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. An amplifier protection circuit, characterized in that: include: Negative temperature coefficient thermistor unit; Main control unit, amplifier chip, speaker; The negative temperature coefficient thermistor unit comprises: a negative temperature coefficient thermistor, a power supply and a pull-up resistor, the power supply is electrically connected to one end of the pull-up resistor, the other end of the pull-up resistor is connected to the main control unit in parallel with the negative temperature coefficient thermistor, one end of the negative temperature coefficient thermistor is grounded, the other end of the negative temperature coefficient thermistor is connected to the main control unit in parallel with the pull-up resistor, the negative temperature coefficient thermistor is arranged at the heating part of the amplifier chip, and the negative temperature coefficient thermistor unit is used to measure the temperature of the amplifier chip, and send a level signal to the main control unit when the temperature of the amplifier chip is greater than a preset value; The main control unit is electrically connected to the amplifier chip and is used to adjust the power of the amplifier chip after receiving the level signal. The amplifier chip is electrically connected to the speaker.

2. The amplifier protection circuit according to claim 1, characterized in that: The negative temperature coefficient thermistor is 10 kilo ohms, and the pull-up resistor is 10 kilo ohms.

3. The amplifier protection circuit according to claim 1, characterized in that: The power supply voltage is 3.3 volts.

4. The amplifier protection circuit according to claim 1, characterized in that: The main control unit is a central processing unit or a digital signal processing unit.

5. The amplifier protection circuit according to claim 1, characterized in that: The amplifier chip and the main control unit transmit signals via the built-in audio bus of the integrated circuit.

6. The amplifier protection circuit according to claim 1, characterized in that: The main control unit is used for sending a communication instruction to the amplifier chip through a bidirectional two-wire synchronous serial bus when the temperature of the amplifier chip is greater than a preset value, so as to reduce the power of the amplifier chip.

7. The amplifier protection circuit according to claim 1, characterized in that: The amplifier chip supports a gain adjustment range from 0 to 36 dB.

8. An electronic speaker, characterized in that The electronic speaker comprises the amplifier protection circuit according to any one of claims 1 to 7.

9. The electronic speaker according to claim 8, characterized in that The electronic speaker is a Bluetooth speaker.

10. The electronic speaker according to claim 8, characterized in that The electronic speaker supports 7-level waterproof function.

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