This circuit can function as both a light alarm and a shadow alarm. The components are common. The circuit includes the power supply. Output transistors must be mounted on heatsinks.
We found this protection circuit for the power supply in a 1992 documentation. This circuit has...
I found this circuit in a documentation for radio amateurs from 1975. The FET could be the BF245....
Found in an American 80's documentation, this circuit can use common FETs like the BF245 and cover...