Found in an Electronic Design from the 80's, this circuit monitors a three-phase line, activating a relay when one of the phases is missing.
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...