Tag: Intercom

Simple Door Intercom

This intercom circuit suitable for accompanying  door bell. This circuit uses the speakers both as microphones and as loudspeaker. This intercom is made simple by using only a single amplifier IC LM390 to serve two-way communication. This circuit is based on master controlled half-duplex operation.  With LM390, a 6V battery supply would produce loud enough volume. Here is the schematic […]

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Category: Audio and Music Tags:

Powerline Carrier-Current Remote Control or Intercom

Using 567 IC tone decoder/detector, we can build a remote control and or intercom. This circuit can be used to control a relay, or to carry an audio signal (intercom) through power-line wiring. Here is the schematic diagram of this remote control/intercom circuit: The relay will be activated if you inject a 100kHz tone. This can be used to control […]

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Category: Control Electronics Tags: , , ,