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.
Found in a magazine 73 for radio amateurs, this circuit operates in the 144 MHz band, at a...
The frequency of this oscillator depends on the crystal. The transistor supports equivalent, and...
This simple bridge circuit can be used for impedance or resistance measurement using a high...