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.
To obtain triangular signals, we have the circuit in the figure that uses two amplifiers. One of...
This circuit was found in an old Electronic Design. It makes use of sidacs and operational not very...
This circuit was found in an American publication from 1969. Transistors are from the time and can be...