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Basic Relay Connection Diagram

Posted: Sat Sep 18, 2010 4:47 pm
by Tech_Marco
A lot of folks don't understand what is a Relay and how it works. Relay is just a like a switch providing On and Off operation. Switch itself doesn't output any voltage unless you apply voltage from one end and get power from the other end once the contact is closed.

Here is a basic terms:
N.O. (Nomrally Opened)
N.C. (Normally Closed)
COM (common)

N.O. become a closed contact (NO & COM) and will conduct current once the relay is energized.
N.C. by default is a closed contacted (NC & COM). It become open circuit (NC & COM) once the relay is energized. So, it will shut off current. N.O. and N.C. is always opposite to eachother, in respect to the COM

See attached images