This circuit was obtained from an American technical manual from the 80's. The integrated circuit is an operational of the time that can be replaced by a modern equivalent.
We found this circuit in the May 1972 issue of Radio Electronics magazine. Its purpose is to teach...
This circuit is from 1985 documentation. The integrated circuit used is not very common today, but...
This circuit consists of a simple continuity test with two transistors forming a relaxation...