http://arduino-info.wikispaces.com/arduinopower explains everything.
When the relay is unenergized there is continuity between A and B. When you energize the relay it switches to provide continuity between B and C.
http://arduino-info.wikispaces.com/arduinopower explains everything.
When the relay is unenergized there is continuity between A and B. When you energize the relay it switches to provide continuity between B and C.