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.
This telegraph monitor was found in an American documentation for radio amateurs from the 1970s. The...
We found this circuit in a European publication from the 1970s. The transistor is made of...
This adjustable source from 2 to 15 V uses transistors from the 60's, as indicated in the...