This circuit was found in a Radio Electronics magazine from June 1962. The circuit is for cars of the time with platinum ignition. The indication is made on an analog instrument.
This circuit was found in an American documentation from the 90's. The circuit can use almost any...
This circuit triggers a relay when light strikes a sensor. The sensitivity is adjusted in the...
We found this circuit on the internet, but it has some problems. It will be convenient to limit the...