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Topic: Relay (Read 474 times) previous topic - next topic

dannyn382

Hello all,

This is my first time posting here as I just got an Arduino, and love it!

My question is I have a 5V relay (http://www.shop.fssindustry.com/V23105A5401A201-V23105A5401A201.htm) but the default on this is without power the relay is closed, so it will pass current. I was wondering if there was a relay like the one that I have, that is the exact opposite, when there is no power the relay will not pass current, only when power is applied to the relay will it allow current to flow.

Thanks for the help!

Dan

Professor Chaos

A "dual throw" relay (SPDT, DPDT) has one set of contacts that is open when the relay is not energized, and another set of contacts that is closed when the relay is not energized.  SPDT and DPDT relays are very common.

arduniomstr

This is the SPDT (Single Pole, Double Throw) relay I've been using in 5V low power projects recently - by connecting to either side of the relay the switch can be either open or closed - it's an RS part but you can get similar parts from lots of suppliers ( 3V versions are also available )
http://uk.rs-online.com/web/p/electromechanical-relays/0476757/

dannyn382

Thanks to you both!

Professor chaos was right! I just moved down a pin and now the relay is the exact opposite, exactly what I needed!

Thanks again!

Dan

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