This circuit was obtained in the 1990 Motorola Linear Databook. The circuit uses a 139 series comparator, but other series can be used. The power source need not be symmetric.
This circuit drives a buzzer or electric buzzer but can be used to trigger a relay or other load....
Found in Popular Electronics from the 90s, this circuit can be used for high voltage applications and...
August 2016 - The new Schottky diodes from Vishay's ESMP series for surface mounting can now be...