This optical coupler for short distances is powered by 12 V which is the voltage of the lamp and the relay. The circuit can also use emitting LEDs and the phototransistor can be of any type.
This switching boost regulator, which provides a 24 V output from a 12 V input, was found in the...
This circuit time the activation of appliances and electronics when the power is cut, thus...
This FM detector circuit was found in a 1977 documentation. The circuit uses a 1977 Signetics...