This circuit was found in an old American publication. The transformer is the type of output found in old transistor radios. The transducer is crystal headphone.
This circuit simulates lightning using a small white lux type fluorescent lamp. The circuit is...
This filter that rejects determines frequency (notch) was found in a Popular Electronics of 1993....
This circuit for electronic voltmeter was found in a publication by Gernsback from 1960. The...