This circuit was originally intended for reading movie soundtracks. The circuit is from 1967 and was found in an English publication. The sensor is semiconductor type.
The sound produced by this circuit, from a 1978 publication, depends on the humidity between the...
This circuit was found in a 1977 American manual. The integrated circuit is from the time....
This small automotive NiCad battery charger uses only passive components and has the number of...