NC CONTACTS

[kwame]

Hi
i have ordered 1 channel opto-isolated IO relay board for a project work.I want install a siren that will be backed up with a 12 VDC car battery(battery backed) so that the siren will sound in the even of power failure.
I Have read that it possible to achieve this by extending the alarm leads to the N/C contacts as there is continuity in NC contacts when the coil is de-energized
.Is it possible to achieve this end?
This anyone have hands on experience in this field?Please help!

 

[shrtrnd]

For an exact answer, we need to know the manufacturer & part number of your relay
board. If you don't know: N/C is normally closed contacts (N/O normally open).
You buy the relay for the type of circuit you want. Most relays have both normally
closed and normally open contacts on the relay, you just need to wire it for the job
you're doing. It helps a lot, when you identify the relay part number (or board), so
we can look it up, and give a more precise answer.

 

[kwame]

Kindly Follow the link below for all the specifications:
http://www.quasarelectronics.com/ct0004-1-channel-isolated-io-relay-board-module.htm

 

[kwame]

Hi
the whole circuit is going to look like maintained emergency lighting system.