This circuit can flash for up to 30 months using alkaline batteries as shown in the table next to the diagram. The circuit is from a Radio Electronics from January 1992.
This circuit of the 1970s uses Germanium transistors. Changes can be made to use silicon...
This circuit was found in an American 1980s documentation. PUTs are rare today. Capacitors C1 and C2 are...
This circuit is from a Radio Electronics from December 1958. It makes use of a photocell of the...