Found in Popular Electronics from the 90s, this circuit can be used in tachometers. The integrated circuit is not a common component today.
A high level on the input of this circuit causes the trim voltage adjusted output voltage to drop to 1.2...
We found this alarm in a 1992 documentation. The circuit has several timings and the relay can...
This windshield wiper interval switch was found in the April 1990 issue of Radio Electronics...