This circuit is from an American documentation from 1975. The circuit uses components of the time which can be replaced by modern equivalents. The coupler is homemade with a lamp and a photocell.
This circuit was found in the March 1979 issue of Radio Electronics magazine. Integrated circuits must...
This is the transmitter for a remote-control system published in the August 1986 issue of Radio...
The current drained by this circuit, from a 1976 documentation, is 3 mA and the cut-off frequency is...