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.
The component used in this circuit is uncommon today, as the circuit was obtained from Motorola's Linear...
This circuit was found in General Electric documentation from the 1980s. The circuit is intended...
Taking advantage of the two stable states of a tunnel diode it is possible to build a switching circuit...