This circuit was found in the August 1996 Electronics Now magazine. The circuit is based on an operational circuit whose type determines the gains and limits for the frequency.
This low current parallel or shunt type regulator was found in documentation from the 60's. The...
This circuit is found in a 1975s documentation for radio amateurs. It was developed to recognize a...
The displayed relay operates with an audio signal applied to the input. The transistors can be...