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.
This 8-channel converter was found in a 1970s American documentation. The integrated circuits used are...
This circuit was found in an old publication and operates in the 455 kHz IF band since the...
This circuit implements a 3-way control, with outputs in A, B and C, using CMOS integrated...