This circuit, suggested by an Electronics World of 1969, keeps a blinking LED for a while when a power outage occurs. Time depends on capacitor C1.
This circuit causes an LED to blink when night falls. Sensitivity is set at R1 and the blinking...
In the figure we have a circuit that uses unusual components, being indicated for low frequency...
Only for reference this is a circuito f a commercial receiver of the year 1958. The circuit uses...