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 uses a Hall device from that time as a sensor. The circuit is from an English...
Found in Radio Electronics from the 90s, this siren finds many variations on this site. The...
This audio generator that produces both rectangular and sinusoidal signals was found in a...