Another of the many tachometer circuits we have on our site. This one is from the September 1976 Radio Elecronics magazine. The circuit is connected to the platinum contacts of a car or to a sensor.
This timer, from an old American publication, uses indicator lamps, but can be modified to use...
This didactic circuit from a 1977 Radio Shack documentation shows how to use the 741 as a...
Found in an 80's Hands On Electronics, this circuit turns on a light when it gets dark and goes...