Found in a Popular Elecronics from the 90s, this circuit appears in other versions in this section and on the website. The circuit draws one of 10 LEDs and has a sound effect produced during the draw.
We found this circuit in a 1986 Elettronica Pratica magazine, but the components used are common. As...
We got this circuit from Radio Electronics from July 1990. The circuit mimics the sound of the red...
This circuit interrupts the power supply when grounding is missing. The circuit is from an old...