Found in a 90s Popular Electronics, this circuit triggers a load from the audio signal applied to its input. The controlled load depends on the MOSFET.
A 0 V signal initiates sampling on this circuit suggested by documentation from the 1970s. The...
We found this circuit in the September 1994 issue of Electronics Now magazine. The circuit uses...
This is the receiver for the previous circuit, also found in 90s Radio Electronics. The circuit...