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 fond in an old publication of the years 1950. The transistors are germanium types and...
The IC used in this project is not common these days, but if you have one you can build a high...
September 2017 - Littelfuse's Polyswitch SMD Resettable PTCs can now be purchased from Mouser...