Found in an Electronic Design from the 90's, this circuit indicates three voltage levels by activating the LED in 3 modes: off, flashing and on for high voltage.
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....