This optically coupled circuit was found in the February 1968 Radio Electronics magazine. The circuit uses an LDR in modulation. Transistors are types of the time.
In the figure we show another interesting application for integrated circuit 4001. This circuit...
Interval pulses emitted by this circuit are picked up in a medium wave radio nearby. The circuit is...
According to the logic level applied to the input of this circuit, X1 is activated and X2 turns...