Based on the well-known LM3909, this LED pulser circuit was found in American documentation from the 90's. The power supply is only 1.5 V.
This circuit, found in an old magazine of the year 1968, uses a Power germanium transistor. This...
This sequential circuit with an optical coupler was found in a Popular Electronics from the 90s to...
This guitar effect circuit was found in a 2002 documentation. The circuit can be powered by a 9 V...