This circuit activates a horn from an audio signal. This can be used for remote control via audio signals. The circuit is from a Radio Electronics from October 1965.
We found this circuit in the August 1970 issue of Radio Elecronics magazine. It uses the CA3018...
This circuit was found in a 1997 documentation. The signals are adjusted in a double 555 (556) and the...
This circuit was suggested by Sprague Electric in an 80's documentation. The circuit uses a...