This circuit appears in several versions in publications of the time and can be modified by changing the capacitors. This one is from Radio Electonics magazine from October 1992.
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...