Found in an Electronic Design from the 90's, this circuit indicates three voltage levels by activating the LED in 3 modes: off, flashing and on for high voltage.
This circuit can be used as a source of signals for generators of different types, sirens, or...
This circuit is based on a 5 V LED flasher. We found it in October 1980 Radio Electronics...
This interesting circuit in which the LED display is circular imitating a common clock appeared in the...