Found in the 1990 special issue of Radio Electronics Experimenter magazine, this circuit uses an automobile ignition coil. Adjustments can be made to suit the coil.
This circuit automatically inverts the test leads connection according to the polarity of the...
With a touch of the push button the lamp is switched on. A new touch and the lamp go out, in this...
This 80's circuit uses a light-sensitive SCR or LASCR and a one-sided silicon switch SUS, uncommon...