Found in a 90s documentation, this circuit appears in other configurations on this site. The circuit can be powered with voltages from 5 to 12 V.
This circuit, which can be used as a shield, was found in American documentation from the 1970s....
This circuit for low frequency data transmission was found in the May 1977 issue of Radio...
This circuit activates a relay that has a lamp as a load. The circuit is from a Radio Electronics from...