This circuit activates a garage door by the car headlights car or a lantern. The circuit is from a 1967 documentation, making use of period components.
This high Q “rejector” or notch filter rejects signals whose frequencies are in the range...
This circuit was found in documentation from the 90's, having an LC compensation network. The...
This two-transistor circuit was found in the January 1994 issue of Electronics Now magazine....