This circuit was found in the March 1984 issue of Radio Electronics magazine. The sensor is a transistor. The module is a common type at the time.
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...