This circuit by Ferranti, in a 1967 publication, is intended for reading perforated tapes. The circuit uses transistors from the era that can be replaced by modern equivalents.
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...