LAB 07 Output transformer less amplifier
Signal Transfer Voltage amplifier Power amplifier Feedback circuit speaker
電容器的帶電量 Q=C*V , C 與電容器兩帶電片間 之距離有關,因此當聲音振動造成帶電片間之距 離改變,電量也隨著變化,此微弱電流再經電容 式麥克風內的電晶體放大,於是可以導通大的電 流。要注意電容式麥克風的兩隻腳的極性,正負 不要接反,與外殼相接的那隻腳是負極。 amplifier 1. Condenser Microphone
MIC 1. Signal transfer 2. Voltage amplifier
Voltage offset adjustment (VR10k)
2. Power amplifier (Push-Pull Output Stage) 1.Q1 only conduct when the input is positive. 2.Q2 only conduct when the input is negative.
Class B amplifier with diode Biasing Simulation load 0.5W 2SC1384 2SA684
MIC
3. Speaker
4. Feedback