In the figure we have one of the many ways to program the counting of a 4017. The circuit uses additional gates and was found in the Radio Electronics magazine of April 1989.
The purpose of this circuit is to monitor the output voltage of a power supply. The under and over...
This circuit, from an old publication from the 70s, uses neon lamps as indicators and can work on...
This high input impedance circuit was found in a Popular Electronics of the 90s. The circuit...