| Author | Message | ||
| Jim Wilkerson (Wagwar)
Registered Member Username: Wagwar Post Number: 185 Registered: 12-2009 Posted From: 69.149.14.14 Rating: N/A |
A vendor recommends that I use two 12 volt relays in series to switch a 12 volt load and a 24 volt load. I thought that a 12 vdc relay indicated the coil voltage and current rating indicated the amount that can be switched. So, following that, it seems to me that I should use 24 vdc relays since the signal wil be 24 volts. If the relay has the correct load rating, it doesn't matter what voltage is being switched. Or will 12 vdc relays work just finre? | ||
| Bruce Henderson (Oonrahnjay)
Registered Member Username: Oonrahnjay Post Number: 730 Registered: 8-2004 Posted From: 70.60.102.148  Rating: N/A |
Jim, just my opinion but I think the "series" business for using two 12V relays for a 24V signal is just asking for trouble. You could also use a 12V light bulb in series with just one 12V relay but is any part of this rig up goes out, you've lost the entire circuit. Also, there are lots of extra connections that can fail or become unfastened. My opinion - get a 24V relay. You can run your signal through the trigger side and 12V through the secondary side. The only caution is that 12V carries double the amperage (same wattage) as 24V so you'll have to be sure that the amperage rating for the relay is good for the device that you're powering off the relay. But once you're OK on that, that relay will work fine for you. It also allows you to "convert" a 24V signal to a 12V working supply. | ||
| George M. Todd (George_todd)
Registered Member Username: George_todd Post Number: 1326 Registered: 8-2006 Posted From: 76.94.211.60 Rating: N/A |
Jim, Do I understand that what you are trying to do is switch a 12V circuit, and a 24V circuit on and off at the same time with one switch? If so, get a double pole relay rated at the amperage you want to switch, with a 24VDC coil. If you have any trouble finding a 24 VDC double pole relay, you can use two single pole relays rated for your loads with the coils wired in parallel. You are correct in your ideas of relay ratings! |