Relay coil and it's normally closed contact question?


#1

assume that we have a relay:
what will happen if we connected the relay coil with the normally closed contact (series connection)of the relay then we applied electricity through the normally closed contact to the coil ?


#2

It will act like a not gate.

When there is no electricity in the first coil it will excite the coil of second relay.

When there is electricity in the first coil it will deenergize the coil of second relay.


#3

The NC contacts are ‘made’, so when the coil is energized, the contacts open. As the contacts open, the coil de-energizes, so the contacts begin to close, but as the contacts close and are ‘made’ again, the coil re-energizes.

The relay will chatter continuously (and sound like a buzzer), cycling between on and off until it destroys itself in a short time.

This relay is not wired for functionality, it is miswired (Power through the NC contacts driving the coil).

In a functional circuit, when an external circuit drives the coil, then the coil’s NC contact will ‘invert’ the state of the coil as poster automate suggests. Coil = ON or logic 1, NC contacts = Open/Off or logic 0.