Found in an old Popular Electronics this circuit can also be adapted to be used as a shield. In this version the control can trigger loads from the light that falls on an LDR.
The CMOS 4046 integrated circuit is not very common today, consisting of a very efficient PLL for...
This old circuit is suitable for signaling applications. The lamp must be incandescent, and the...
In the figure we show how the half wave rectification of a signal can be done using an operational...