This circuit, which controls both the temperature and the level of a liquid in a reservoir, was found in an Electronic Design from the 90s. The circuit is based on a double 555.
This circuit is from the 1983 Intersil Databook. In it we have the use of the ICL7135 as an AD...
This MW radio circuit with varicap tuning was found in an English documentation from 1989. The...
This circuit was found in an American publication from the 70s, but it can be assembled with more...