This circuit cuts the audio for a few seconds between words, which allows ads to be detected, since this does not occur in music. The circuit is a from Radio Electronics Experimenter from 1989.
This General Electric circuit is from the 80's. The PUTs used in this meter are not common...
This circuit provides a power of the order of 2 W, characterized by high performance. The output...
The sensor can be made using two bare wire or two screen with a piece of tisse between them. One...