This photoelectric sensor that triggers a relay was found in an English book from 1989. The transistor is a general-purpose type, and the integrated circuit consists of an operational amplifier.
The output current of this power supply depends on the power transistor and the transformer and...
This voltage inverter uses a small transformer. The circuit was found in the April 1995 issue of...
This 1969 Popular Electronics circuit was based on the then recently released BC109, today with...