论文部分内容阅读
本助听器实际上是一个超小型的扩音器。它包括传声器,前置放大器,音频功率放大器和受话器四部分。由于本电路采用前置和功率放大,对信号放大率高,故可加入反馈电路及高频旁路、低噪声放大,并使用驻极体传声器,故音质较好,噪音低。工作原理,如图所示。来自传声器的微弱信号,由耦合电容C_2输入到低噪声管BG的基极,使BG组成的电压并联负反馈放大器进行
This hearing aid is actually a very small loudspeaker. It includes the microphone, preamplifier, audio power amplifier and receiver four parts. As this circuit uses front and power amplifier, high signal amplification, it can join the feedback circuit and high-frequency bypass, low noise amplification, and the use of electret microphones, so the sound quality is good, low noise. Working principle, as shown. The weak signal from the microphone is input to the base of the low-noise tube BG by the coupling capacitor C_2 to make the voltage of the BG composed in parallel with the negative feedback amplifier