Automatic thermal callback control circuit for power of automobile power amplifier
Through the combination of thermal sensor and comparison operational amplifier, automatic thermal callback control of the automotive amplifier is realized, which solves the downtime caused by overheating of the amplifier, extends working time, reduces cost and volume, and improves sound quality and user experience.
Patent Information
- Application Number
- CN202323440273.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2023-12-15
- Publication Date
- 2025-03-14
- Estimated Expiration
- 2033-12-15
AI Technical Summary
Automobile power is prone to overheating when working at maximum power and maximum load, resulting in repeated cycle shutdowns, affecting user experience, and the prior art increases the volume and cost of radiator, or uses complex Class D technology to solve the problem at the expense of sound quality and cost.
Use thermal sensors to detect the amplifier temperature, compare the output control signals of the operational amplifier, control the signal voltage of the amplifier, and automatically call back the output power to avoid premature thermal protection shutdown.
The amplifier is realized for a long time without shutting down due to overheating protection, which reduces the demand for radiators, reduces cost and volume, and improves the sound quality and user experience.
Smart Images
Figure CN222621165U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of automobile power amplifiers, in particular to an automatic thermal callback control circuit for automobile power amplifier power. Background Art
[0002] When the car amplifier is working at maximum power and maximum load, it generates a lot of heat, especially Class A and Class AB amplifiers with relatively low efficiency, which will quickly enter the overheat protection shutdown. It is necessary to wait for the temperature to drop to the operating range of the amplifier before the amplifier can resume working. After working, when the temperature reaches the overheat protection level again, the amplifier starts to shut down again. This repeated cycle makes the user have a poor experience.
[0003] In order to prevent the amplifier from entering thermal protection too early, most amplifiers currently have to increase the size and weight of the radiator or the fan to speed up the heat dissipation of the amplifier and extend the working time of the amplifier in order to match the power demand. The disadvantage of this method is that it will increase the cost and increase the size of the amplifier, which is not convenient for installation in the car. In addition, there is also a more efficient Class D technology. Under the same power, it does not require a larger radiator and can work for a long time, which solves the problem of the size of the amplifier well, but its circuit is complex, the interference is large, the sound quality is not as good as Class A and Class AB amplifiers, and the overall cost is also high. Based on the above problems, we use the following technical solutions to solve them.
[0004] A thermal sensor is used to detect the temperature of the power amplifier. Before the radiator temperature of the power amplifier is about to reach the overheat protection shutdown, the thermal sensor converts the thermal signal into a voltage signal, and outputs a control signal through a comparison operational amplifier to control the signal voltage of the power amplifier, so that the output power of the power amplifier is automatically adjusted back, allowing the power amplifier to keep working for a long time and avoiding the power amplifier from entering the thermal protection shutdown too early. Therefore, technical personnel in this field provide an automatic thermal adjustment control circuit for automotive power amplifiers to solve the problems raised in the above background technology. Utility Model Content
[0005] The utility model aims to provide an automatic thermal callback control circuit for automobile power amplifier power to solve the problems raised in the above background technology.
[0006] In order to achieve the above purpose, the utility model provides the following technical solutions:
[0007] The utility model provides an automatic thermal callback control circuit for automobile power amplifier power, comprising an audio signal, wherein the output end of the audio signal is electrically connected to a channel 1 preamplifier and a channel 2 preamplifier respectively, the output ends of the channel 1 preamplifier and the channel 2 preamplifier are electrically connected to a channel 1 power amplifier and a channel 2 power amplifier respectively, the output ends of the channel 1 power amplifier and the channel 2 power amplifier are both electrically connected to speakers, a power supply is electrically connected between the channel 1 power amplifier and the channel 2 power amplifier, and the output end of the power supply is electrically connected to an automatic thermal callback control circuit for power.
[0008] Compared with the prior art, the beneficial effects of the utility model are:
[0009] The utility model utilizes a thermal sensor to detect the temperature of a power amplifier. Before the temperature of the radiator of the power amplifier is about to reach the overheat protection shutdown, the thermal sensor converts the thermal signal into a voltage signal, and outputs a control signal through a comparison operational amplifier to control the signal voltage of the power amplifier, so that the output power of the power amplifier is automatically adjusted back, allowing the power amplifier to keep working for a long time and avoiding the power amplifier from entering the thermal protection shutdown too early. BRIEF DESCRIPTION OF THE DRAWINGS
[0010] Figure 1 It is a structural block diagram of the automatic thermal callback control circuit of the automobile power amplifier;
[0011] Figure 2 This is the circuit diagram of the automatic thermal callback control circuit for the car amplifier. DETAILED DESCRIPTION
[0012] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.
[0013] See also Figure 1-2 The utility model provides an automatic thermal callback control circuit for automobile power amplifier power, including an audio signal, wherein the output end of the audio signal is electrically connected to a channel 1 preamplifier and a channel 2 preamplifier respectively, the output ends of the channel 1 preamplifier and the channel 2 preamplifier are electrically connected to a channel 1 power amplifier and a channel 2 power amplifier respectively, the output ends of the channel 1 power amplifier and the channel 2 power amplifier are both electrically connected to speakers, a power supply is electrically connected between the channel 1 power amplifier and the channel 2 power amplifier, and the output end of the power supply is electrically connected to an automatic thermal callback control circuit for power.
[0014] The U1-A operational amplifier and the R5, R6, and R7 resistors form a temperature detection and comparison operational amplifier circuit, the D1 rectifier diode and the C3 filter capacitor supply power to the operational amplifier circuit, the R8, R9, and R10 resistors, the Q1NPN transistor, and the K1 relay form a signal drive circuit, the R1, R2, R3, and R4 resistors form an audio signal voltage divider circuit, and the C1 and C2 are signal coupling capacitors for channel 1 and channel 2.
[0015] The working principle of the utility model is: when the radiator temperature does not reach the temperature of thermal correction when the power amplifier is working, the resistance of the RT thermistor becomes larger, the voltage of the + foot (positive phase input) of the comparison operational amplifier is lower than the voltage of the - foot (negative phase input), the output of the operational amplifier is low level, the Q1 transistor is cut off, the K1 relay does not work, the switch is normally open, the audio signal is not divided, and the power amplifier outputs at maximum power. When the radiator temperature reaches the temperature of thermal correction, for example, 58°C (the temperature value of thermal correction can be adjusted by R5, R6, and R7 voltage divider resistors), the resistance of the RT thermistor becomes smaller, at this time, the voltage of the + foot (positive phase input) of the comparison operational amplifier is higher than the voltage of the - foot (negative phase input), the output of the operational amplifier is high level, the Q1 transistor is turned on, the K1 relay works, the relay switch is closed, R3, The R4 resistor is grounded, and the audio signal is divided by R1, R3 and R2, R4. The signal voltage output to the power amplifier circuit is reduced, so that the output power is reduced. After the power is reduced, the temperature of the power amplifier radiator is gradually reduced. After it drops to a temperature below the thermal correction temperature, the power amplifier outputs at the maximum power, so that the power amplifier can maintain a long working time and avoid premature thermal protection shutdown. The utility model realizes the power amplifier without increasing the volume and weight of the radiator or fan heat dissipation, and can make the power amplifier work for a long time without prematurely entering the overheating protection shutdown, so that users have a better listening experience, and also make the power amplifier smaller and lighter, with a simple circuit, simple testing, stable operation, few components required, small size, convenient PCB design, no special requirements for the required materials, low cost, convenient procurement, etc., and is suitable for various types of power amplifiers such as multi-channel or home use.
[0016] What is described above is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes within the technical scope disclosed by the present invention according to the technical scheme and the utility model concept of the present invention, which should be covered by the protection scope of the present invention.
Claims
1. The car amplifier power automatic thermal callback control circuit, including audio signal, is characterized by: The output ends of the audio signal are electrically connected to channel 1 preamplifier and channel 2 preamplifier respectively, the output ends of the channel 1 preamplifier and channel 2 preamplifier are electrically connected to channel 1 power amplifier and channel 2 power amplifier respectively, the output ends of the channel 1 power amplifier and channel 2 power amplifier are both electrically connected to speakers, a power supply is electrically connected between the channel 1 power amplifier and the channel 2 power amplifier, and the output end of the power supply is electrically connected to a power automatic thermal callback control.