This circuit, found in 2002 documentation, triggers LEDs when a phone call is received. The LEDs will flash alternately in these conditions. Common LEDs are used in this circuit.
The frequency of this circuit can be varied from zero. The circuit uses the CMOS 4046 and was...
This circuit detects the sound of thunder, assessing its intensity and thus the distance of a...
This circuit was found in a 1965 General Electric manual. It is intended for cars that have...