This is a battery powered 3W power amplifier using germanium transistors. The circuit is from an English documentation from 1967. The transistors are from the time.
Found in a Popular Electronics from the 90s, this game can be seen in other configurations on this site. The...
This control for a heating element was found in an old documentation. The current in the element...
This circuit is from an American documentation of 1975. The FET may be the BF245 and the relay is of...