This circuit reminds the driver when he removes the keys from the ignition, leaving the lights on. The circuit is from an August 1974 Radio Electronics magazine.
This game was found in an old Popular Electronics. The unijunction transistor can be 2N2646. The...
This circuit interrupts the power supply when grounding is missing. The circuit is from an old...
In figure 1 we have a circuit that turns on after a certain time and then turns off, also after a...