(Read 541 times)
Dec 27, 2011, 08:36 am
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!
Dec 27, 2011, 09:21 am
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.
Dec 27, 2011, 10:14 am
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 )
Dec 27, 2011, 07:08 pm
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!