This 6-transistor Japanese radio from the 1960s used germanium transistors and had an output power of 180mW. The circuit is of the superheterodyne type with push-pull class B output.
This alarm circuit is from a 1990 Electronics Handbook. Transistor Q1 can be a BD135 and the relay...
This trigger circuit was found in old European documentation, but it can be implemented with...
This circuit is from the SGS Integrated Circuits Manual of 1982. The integrated circuit used is...