We found this circuit in a Radio Electronics Experimenter from 1990. The circuit uses a common incandescent bulb and a car ignition coil.
The LEDs, in addition to flashing if the transistor is good, also indicate the polarity of the...
This circuit was found in a 1980 documentation. It is an interesting 3-track radio circuit whose...
This alarm circuit was found in the July 1992 Radio Electronics magazine. The circuit uses a small...