Two transistors on a regenerative switch are used to trigger a triac. This circuit is from the RCA Power Circuits manual. Transistors admit equivalents.
This high selectivity or high-Q filter can be implemented with almost any operational amplifier. The...
This simple game in which the player has to guess the chosen position of the key was found in a...
The circuit shown in the figure is based on the four comparators of the LM139 or series...