This JFET amplifier stage was found in the Encyclopedia of Electronic Circuits Volume 5 from 1995. Any JFET can be used and the bias controlled externally.
This circuit is used to obtain the synchronized activation of a mechanical battery clock. The...
ON Semiconductor Phototransistor Output Optocouplers Available from Mouser Electronics is the...
Found in an Electronic Design from the 80's, this circuit monitors a three-phase line, activating a...