This circuit was found in the July 1986 issue of Radio Electronics magazine. The circuit has a loudspeaker warning system. The sensor is the ceramic capacitor C1 which acts as a transmission line.
April 2017 - Mouser Electronics is making available this new component for open LED protection...
This CMOS logic-based circuit was found in the April 1974 issue of Radio Electronics magazine. The circuit...
The transistor in this circuit can be replaced with any general-purpose equivalent. The time...