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.
This circuit was found in a 1965 Electronic Design. The transistors are of the time, but the...
Found in a 90s Popular Electronics, this sensor operates by infrared reflection. The components are...
The time of this timer depends on C1. The circuit was found in the July 1994 Electronics Now...