This alarm circuit with NC sensors in series was taken from an article in Radio Electronics magazine from May 1971. The SCR can be any of the 106 series.
This basic circuit was found in RCA / GE documentation from the 90s. In it we have the way to...
The ICL8038 is a function generator that appears elsewhere on this site in various applications. The...
We found this voltmeter in a 1977 Radio Shack documentation. The integrated circuit can be the...