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伴音功放电路的作用:主要是将鉴频器输出的音频信号进行功率放大,推动扬声器播放电视伴音。虽然新型彩电的伴音功放电路大多是采用集成电路,但其基本结构和工作原理,与分立元件功放电路基本相同。从结构上看,伴音功放电路主要包括激励级和输出级两个部分,信号的输入与输出一般采用电容耦合,而激励级和输出级之间一般采用直接耦合,且通常都设有负反馈电路,以稳定静态工作点。从功能上看,伴音功放电路是将输入的音频小信号进行功率放大,故要求失真小,效率高。图1是参考东芝X53P机芯彩电绘制的伴音功放电路原理图。从鉴频器输出的音频信号,经音量控制、前置放大后,由耦合电容C613输入
Audio amplifier circuit role: The main is the frequency of the audio signal output frequency amplifier for power amplification, promote the speaker to play TV sound. Although the new color TV PA amplifier circuit are mostly integrated circuits, but its basic structure and working principle, and discrete components amplifier circuit is basically the same. From a structural point of view, the sound power amplifier circuit includes two parts: the excitation stage and the output stage. The signal input and output are generally capacitively coupled. The direct coupling between the excitation stage and the output stage is generally adopted, and the negative feedback circuit , In order to stabilize the static working point. From a functional point of view, audio amplifier circuit is the audio input small signal power amplification, it requires less distortion, high efficiency. Figure 1 is a reference Toshiba X53P mobile TV audio amplifier circuit diagram drawn. From the frequency discriminator output audio signal, the volume control, pre-amplification, the coupling capacitor C613 input