PROJECTS

摘要

If you like electronic puzzles, then this kitrnis for you! There are no integratedrncircuits; all functionality is achieved usingrndiscrete transistor-diode logic. The PCB isrn10"× 11" and harbors more than 1,250rncomponents! For more info, see thernNovember 2009 issue.rnAs seen inrnthe Novemberrn201 I issue.rnBattery Marvelrnhelps protectrncars, trucks,rnmotorcycles,rnboats, and anyrnother 12Vrnvehicles from sudden battery failure. Thisrneasy-to-build kit features a single LED thatrnglows green, yellow, or red, indicatingrnbattery health at a glance. An extra-loudrnpiezo driver alerts you to any problems.