This circuit was found in the 1991 Electronics Experimenter's Handbook. It activates a relay when light shines on a sensor.
This circuit is from an old technical documentation from Spain. The circuit uses a FET that is...
Using transistors at the time, this circuit was found in a 1967 Ferranti documentation. The...
This circuit is from a thyristor manual from On Semiconductor. It makes use of a PUT and a SCR...