The working principle and function of the car audio power amplifier：

The amplifier effect is from sound source or weak signal pre amplifier is expanded, in order to promote the speaker burst. A good effect of the sound system amplifier can not do without.
Amplifier as a big guy all kinds of audio equipment. It is mainly imported audio equipment for weak signal to expand, meet the current to promote a speaker sound playback. Due to consider power, impedance, distortion, dynamic and not the same as the scope of the use and control of conditioning function, not the same as the power amplifier in the internal signal processing, line planning and production processes are not the same.
Car stereo system with the same home audio, the use of power amplifier to make all the system in good condition. Assume that the car is just touch the sound of people, on the car in the power amplifier, and even the device more than one power amplifier, may find it difficult to imagine. This from the car itself is concerned, because the car's power supply voltage is usually only 14.4V, power (P) = voltage (U) x current (I), up to 4x55W. Assuming that only the power of the host itself is used to expand the power of the speaker, only to push the small power of the speaker, and the volume will open up the distortion, sound stiff, lack of flexibility. Ear hearing is limited, and its lower limit than the volume of the upper limit can be heard, this can explain why the sound at the beginning of a more intense feeling, it will feel weak. To make any sound to reach the most realistic situation, on today's skills can not be processed. The impact of noise caused by the noise that is announced by the engine, the engine and the chassis and the tires on the road surface is not negligible for listening to the environment. Only adding power amplifier, ability to deal with low sound pressure level and level power and lack of disadvantages, replay music all the information. Assuming the power amplifier inside the use of inverter power supply, the power supply voltage to the 40V control, power will also be improved, so we can promote the high power speaker. Because the storage volume of the power increase, progress will not happen with elastic distortion, strong sound. Especially in the promotion of a large scale of the low voice speaker, the low voice area more extended, sound becomes plump, so this problem can be solved easily.
In fact, the amplifier is a high fidelity audio signal recovery. Let's make a simple example, the original power amplifier, such as the work of the copy machine. Why should the concept of the two wind horse and pull together, listen to me carefully one by one. Their essential effect is to copy something, just as the copy machine can copy the smaller paper into larger paper. If you go to the original A4 copy paper, then you in addition to get the A4 paper copy, can also get A3 and A1, even more paper and a copy of the new originally known as is the original editions, this you self according to need can manipulate conditioning. Power amplifier is exactly like the copy machine, the original copy is not the root. After the signal is processed by the original audio signal recovery enhanced version, the volume is greater than the source audio input. It changes only the volume of the audio input, and the tone has not changed. If its tone is also changed, the wavelength and frequency of it will be changed accordingly. This article will not make specific and in-depth discussion on this topic. This is easy to understand, appropriate. Now, I think we should have a general understanding of the amplifier. In short, the car amplifier that is the input terminal (host, CD player and so on) to restore the audio input to expand, while making it to meet the intensity, so that the unit can be a dynamic speaker.
The power to expand the work principle is to control the voltage on current channel size to reach the current size of the intentional manipulation. Using the current control effect of the transistor or the voltage of the field effect tube to control the power conversion to the current according to the change of the input signal. Because the sound is not the same amplitude and frequency of the wave, namely communication signal current, the collector current of the transistor is always times base current beta, beta is triode communication multiples to expand, the use of this, if the small signal is written into a base, flowing through the collector current will equal to the base current beta times, then the signal across the capacitor blocking out, get the current (or voltage) is the original beta times large signal, the scene into a triode broadening effect. After constant current and voltage, the power is expanded. And the field effect tube is gate voltage to control the source pole and drain current, its control effect with transconductance suggests that gate change a MV, the source current change an, said GM was 1, power broadening device is to use these results to complete small signal control signal, so that multi-stage expansion device to complete the high power output, not really will, the expansion of the power! They are converted to power, not the expansion of energy. We still need to observe the laws of conservation of energy in our today's skills.