This circuit is the digital indicator for the previous circuit and can be used with similar circuits. The circuit is from an article in Radio Electronics magazine, June 1987.
This circuit from a Radio Electronics from February 1976 activates the relay in two different ways...
The integrated circuit used in this project is unusual and it includes internal transistors that...
This circuit is quite old, from 1964, but can still be mounted with BC558 transistors. The circuit is...