The Working Principle of Power Amplifier

Jul 23, 2020

The essence of power amplifier amplification is to convert the DC power provided by the power supply to the amplifier into AC power on the load through the control of the transistor. Under the large signal working condition of the transistor, the working point will swing up and down greatly. Once the operating point jumps out of the linear region of the input or output characteristic curve, nonlinear distortion will appear. Therefore, for audio power amplifiers, the output power must always be considered in conjunction with nonlinear distortion.

The working principle of the power amplifier is to rely on the voltage to control the size of the power supply channel, so as to achieve the purpose of controlling the size of the current. It uses the current control function of a triode or the voltage control function of a long-effect tube to convert the power of the power supply into according to the input The current of the signal change, because the sound is a band of different amplitudes and different frequencies, which is the AC signal current. The current of the triode and the electrode will always be beta times of the polar current. Beta is the AC amplification of the triode. Applying this point, if a small signal is injected into the base terminal, the current flowing through the polar electrode will be equal to the beta of the polar current. Times. The power amplifier itself uses these functions to realize the small signal control the large signal, so that the multi-stage amplifier realizes the high-power output, not really amplifying the power.

The above is the working principle of the power amplifier. If you want to know more, please go to the official website of Milliway Microelectronics Co. Ltd.

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