One more switch question....
07-04-2014, 02:24 PM
#1
One more switch question....
Ok, I have three seperate circuits with switches for various led strips throughout the truck, but I want to wire one more fancy switch that turns on all 3 at the same time for my "zombie apocalypse mode" switch. I did some bench testing and connected the output wire from my zombie switch to the outputs of the other switches and it turns them on but it's not isolated. When I turn on one of the other switches, they all go on still. I was thinking about adding a diode to the wires from my zombie switch to the other switches to isolate that circuit and prevent backfeed, is this the correct way of doing it or is there a better method?
07-04-2014, 03:59 PM
#2
Several ways to do this. One is diode isolation as you are considering. The diodes would attach to the "zombie" switch and go to each of the loads. My biggest concern with this is the possibility that leakage current may allow the other strings to glow slightly since it takes so little current to provide some light with a LED.
Another option would be to have the zombie switch control relays that then switch each of the load legs. 3 of the standard SPDT or SPST relays would be required. You can buy them through ebay for next to nothing, they just take up space. If you can find relays with more poles you could use fewer relays. I searched for "12v relay 3 pole" on ebay and turned up quite a few.
Finally, you may be able to find a a triple pole switch (basically 3 switches in one). They are somewhat harder to find, especially if you want them to match the other switches you are using. Double pole switches are easy, but would only work for 2 of your strings.
Hope this helps.
--Rick
Another option would be to have the zombie switch control relays that then switch each of the load legs. 3 of the standard SPDT or SPST relays would be required. You can buy them through ebay for next to nothing, they just take up space. If you can find relays with more poles you could use fewer relays. I searched for "12v relay 3 pole" on ebay and turned up quite a few.
Finally, you may be able to find a a triple pole switch (basically 3 switches in one). They are somewhat harder to find, especially if you want them to match the other switches you are using. Double pole switches are easy, but would only work for 2 of your strings.
Hope this helps.
--Rick
07-04-2014, 07:49 PM
#3
Several ways to do this. One is diode isolation as you are considering. The diodes would attach to the "zombie" switch and go to each of the loads. My biggest concern with this is the possibility that leakage current may allow the other strings to glow slightly since it takes so little current to provide some light with a LED. Another option would be to have the zombie switch control relays that then switch each of the load legs. 3 of the standard SPDT or SPST relays would be required. You can buy them through ebay for next to nothing, they just take up space. If you can find relays with more poles you could use fewer relays. I searched for "12v relay 3 pole" on ebay and turned up quite a few. Finally, you may be able to find a a triple pole switch (basically 3 switches in one). They are somewhat harder to find, especially if you want them to match the other switches you are using. Double pole switches are easy, but would only work for 2 of your strings. Hope this helps. --Rick
07-05-2014, 01:34 PM
#4
The only reason the diode leakage even comes up is the extremely low amount of current required to cause a LED to glow. It is not an issue with incandescent bulbs or relays. Just connect the diodes between the "zombie" switch and the coils of the relays and you will be golden.
--Rick
--Rick
07-05-2014, 02:28 PM
#5
The only reason the diode leakage even comes up is the extremely low amount of current required to cause a LED to glow. It is not an issue with incandescent bulbs or relays. Just connect the diodes between the "zombie" switch and the coils of the relays and you will be golden. --Rick
As always, I learned something new. Thanks for taking the time to reply!