This circuit keeps a set of lamps permanently on, even when there is a power cut. The circuit can be adapted to use LEDs and the 12 V battery can also be changed according to the lamps or LEDs.
Two 3-terminal regulators like the LM317 can be used to "clip" a sinusoidal signal, in order to...
This 7400 TTL circuit has a memory, keeping the LED on when a pulse is detected. The circuit must be...
This sole beacon which has a battery charged by photocells was found in documentation from 1991....