This simple circuit for headphones or small speakers was found in documentation from the 90s. The circuit works with voltages from 5 to 9 V and has good gain.
This railroad model circuit was found in a 1960 Sylvania transistor manual. The components are from that...
This circuit samples the current in a load and in case of excessive value it activates a...
We found this circuit in a 2004 documentation. The circuit consists of a standard lamp for testing...