Welcome to CircuitLib.com, the Electronic Circuits Library. Let’s share our Knowledge with hobbyists, individuals, groups and students as widely as possible! Navigate to our pages and discover many novel electronic circuits. The electronic library is regularly refreshed with new circuit schematics, complete electronic projects, tutorials and links for junior and senior courses in electronics engineering. We emphasize on constantly working to produce innovation and present new knowledge, ideas, and vision.

Countdown Timer

The specific count down timer was initially designed for a UV-Exposure Unit. However, it proved to be extremely useful for providing controlled "on" times for other equipment such as photo-enlargers, developers, small heaters, incandescent lamps, fluorescent lamps, etc.