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 circuit was found in an English documentation from 1969. The transistors are of the time,...
When establishing the voltage at the input of this regulator, the output voltage rises smoothly until...
To obtain an AND gate we have the configuration shown in the figure. With the values indicated for the...