Very simple and useful circuit for communication between two person. The Q1 is used to amplify the weak output signal of speaker when one push his (her) side push-button to speak. The base-common configuration of the Q1 pre-amplifier is for matching low impedance speaker with input impedance of the pre-amplifier, then it can amplify the output speaker signal well. To drive the speaker, the circuit use an audio power amplifier IC, LM380. The circuit can be build on a vero board to obtain a good result, but if you use a PCB, it will work better and using of it will be easier.

Title: Simple Intercom
Source: unknown
Published on: 2005-08-27
Reads: 1228
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