I just bought 12 5VDC DPDT relays for a VGA & USB switch I'm building... Item RLY-422 from AllElectronics.com [ LINK ]. Now, I didn't know it was so complicated to read a relay. There are 6 poles: 1. 2. | 3. 4. 5. | 6. Between poles 3 and 6 there's a little coil, which I assume means I run the voltage through there. Poles 1 & 4 are marked "NO" for what I assume means Normally Open as described by the retailer, poles 2 & 5 are marked COM, which I have no idea what that means Now see that line between 1, 2, 4 & 5 and 3 & 6? That's noted as NC 2 for the bottom row [ the diagram rotates the relay 90 degrees ] and NC 1 for the top row [ 1, 2, & 3 ]. I should also note that I did try running 5VDC through poles 3 & 6, but it shorted my AT PSU causing it to shut off. I'm assuming that it's simply shorting across the 5V line which should normally cut it off but the site says it's a 36 Ohm coil... shouldn't that be some load enough to run it?
It's a DPST switch system, in at 2, out at 1 for one pole and in at 5, out at 4 for the other. COM stands for common, but doesn't apply here as the NC contacts aren't fitted. The ATX psu needs about an amp load current to work, the relay is only giving it 5/36 (0.14A) load. I'd put a 1N4001 diode across 3 & 6 (cathode to positive) or you'll risk messing up the psu.
