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Define "Normally Open" vs. "Normally Closed"
I'm replacing a broken surface mount magnetic switch mounted on my
garage door that controls a signal light in the house that comes on when the door is open. Thus, I need a switch that is OPEN (meaning no current flows) when the magnet is near the switch and CLOSED (meaning current flows) when the magnet is removed from the switch. So do I need a normally open switch or a normally closed one? Different manufacturers/vendors seem to use the terms differently. Is it "normal" when the magnet is near the switch-- or away from it? |