This receiver for a modulated light intercom was found in a 90s Elektor. The audio amplifier can be replaced by an equivalent. The sensor can be any phototransistor.
Indicated for vinyl media recovery, this circuit is from the 80's, having been found in an...
This circuit aims to take advantage of two old telephone sets in an efficient domestic intercom...
This circuit can be used for signaling a panel with a common incandescent lamp. The lamp will...