This sonic relay or vox was found in a Popular Electronics from the 90's. The power MOSFET can be of any type determining the controlled load.
This test consists of a simple Hartley oscillator using a transformer of the type found on older...
The integrated circuit used in this 80's application is not common today. However, modern...
This circuit is from 1983 documentation. The author shows us an experimental circuit of a siren...