驻极体传声器小型前置放大器的设计

传声器是一种将声信号转变为相应的电信号的电声换能器。驻极体传声器是一种用驻极体材料制造的新型传声器。由于驻极体传声器的输出阻抗很高不能直接与音频放大器相接,需要在传声器内接入一只输入阻抗极高的结型场效应三极管来进行阻抗变换。一些小型的驻极体传声器虽然可以将场效应管集成于传声器内部,但是价格高昂;而传统的前置放大器体积又过于庞大。针对此利用现有的技术条件,设计了一种体积小、成本低廉而性能优良的前置放大器。

A Design of Small Preamplifier for Electret Microphone

The microphone is one kind of transducers that transforms the sound signal into the corresponding electrical signal. The electret microphone is a new microphone which is made with the electret material. Because the electret microphone＇s output impedance is very high that cannot directly connect with the audioamplifier, and needs to inscribe a knot field effect triode tube with extreme high input impedance in microphone to carry on the impedance conversion. Although some of the small electret microphone can integrates FET in the internal of microphone, but it costs high; and the volume of traditional preamplifier is so huge. This article designs a pre-amplifier of small, low cost and good performance with the existing technology.