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.
WWV is the prefix for the United States' time and frequency patterns station. These signals can be used...
This wired control circuit serves both volume and balance between channels. We found it in Radio...
This circuit produces a loud audio tone by a small loudspeaker. Power supply voltage ranges from 5...