We found this circuit in the July 1992 issue of Radio Electronics magazine. An optical system produces the light beam that, when interrupted, triggers the alarm. The sensitivity is adjusted by R4.
May 2016 - It can be obtained from Mouser Electronics new microcontrollers from Texas MSP430...
This passive circuit was found in a 1980s documentation. The circuit serves to indicate the...
This circuit can be adjusted to time timer intervals up to1 hour using a 2,200 µF capacitor and a...