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 appears on the site in several variations depending on the source. This is from a...
This counter performs the same function as the 4020, but includes an internal oscillator. The...
Found in a 1968 Electronics World, this circuit uses operational amplifiers from that time. |...