For analog lines, this circuit was found in the August 1994 issue of Electronics Now magazine. The transistors are common general-purpose types.
This circuit is from an old American documentation. The circuit generates 20 to 200 ms steps for...
This circuit, found in American documentation, works as a voltage doubler, enabling the supply of a...
This circuit was taken from a Popular Electronics from January 1967. Transistors are from the...