This toy transistorized organ was found in the May 1970 issue of Radio Electronics magazine. The trimpots are adjusted to the musical notes according to the key.
The presented circuit has compensation for cold junction. In addition to a voltage reference, it...
This “people detector” with pyroelectric sensor was found in the April 1991 issue of Radio...
This circuit from a 1988 documentation uses an NTC sensor to keep a greenhouse temperature...