This circuit can be used as an answering password system in a store, office, or other location. The circuit is from Intersil using components of the time. The circuit is from the 80's.
This circuit was found in the January 1995 Electronics Now magazine. The source must be dual, and...
Found in an 80's Elektor, this circuit can use any equivalent optical coupler. The buzzer is of the...
This compressor that enhances the voice range is from the 1990 Motorola Linear Databook. The...