This circuit triggers a relay when a light beam that hits the phototransistor is cut off. The circuit is from Electronics Now and the supply voltage depends on the relay voltage.
This circuit has a power stage with transistors that allows to obtain a current greater than that...
This circuit converts signals from the shortwave band to the 118 to 130 MHz VHF band used in...
We found this circuit in an old publication dealing with operational amplifiers. The circuit uses...