This optical counter was found in a 1964 Electronics Design. It makes use of an uncommon optocoupler today, using emission lamp and a phototransistor.
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...