Organize and Share your Electronics the way you want. Sign-Up for a free account now. It takes only 30 seconds!
Simple Polarity Tester
This tester can be used to check the polarity of any power source, and is therefore very useful when installing automotive equipment, alarm systems or anything else you can think of. Because this circuit is so simple and cheap, even frying one with an over voltage is not a big deal.
Part Total Qty. Description Substitutions
R1 1 1K 1/4W Resistor D1 1 Green LED D2 1 Red LED D4, D5, D6, D7 4 1N4001 Silicon Diode 1N4004, 1N4005, 1N4007 MISC 1 Board, Wire, Case, Probes