This circuit is for traditional old-style telephone lines found in an American 1980s documentation. Components are common and the optical coupler can be replaced with an equivalent.
Found in a 1995 Hands On-Electronics, this circuit generates a sinusoidal signal whose frequency...
This circuit was found in the January 1996 issue of Electronics Now magazine. The circuit is...
We found this circuit in a 1982 documentation. It uses a CA3140 or equivalent operational...