This circuit makes use of an optical coupler to isolate the telephone line. The circuit is from 1970s documentation. The components admit equivalents.
This circuit was found in old FET documentation, but it applies to any modern common JFET. The...
The different aspect of this source is the use of a 12 V lamp as a current regulator together with a...
This circuit makes simultaneous control of two up to 150 W incandescent lamps. The circuit is half wave...