Using Mains LEDs on 12v

[kapt]

Sorry if this has been covered before - but searched & couldn't find exact problem.
I wanted approx. 1000 lumen central recessed ceiling LED downlight (max. depth about 20mm). Found really neat white aluminium body (20mm deep) about 6" diam. light on eBay. It was advertised with 'driver' for 220v - (presumably for use on mains household systems). I had previously bought smaller G4 halogen household cabinet downlights and converted them to G4 LED to run directly off 12v with no problem. I guess I thought - same with the bigger one - just throw away the transformer/driver & it will be fine on 12v. - NOT SO !
Does anyone have any idea whether there would be a way of making this work? The light itself is just what I need - but it would be better if it actually produced light!

 

[TonyJones]

Hi "kapt," and welcome.
Without seeing the kit you've got it's hard to suggest what to do, but have you looked at the label on the transformer that came with the lights? If that has an output of 12vDC, then I'd expect the lights to work just as well from any other 12vDC source (such as your van's supply).
If the voltage is right and they're not working, could there be something wrong with the wiring of the lights?

 

[laimeduck]

Hi - I'm no electrician but I do know that LED's have to be wired correctly ie they have polarity. As long as its 12volt, just swap the wires over & they may well work. I have wired in LED's throughout my van, and found this out the hard way!
Let us know?
Jeremy

 

[StuartO]

Individual LEDs aren't suitable for 12v power either, which is why they are mounted within strips as sets of three or four in series with a resister to limit the current flow.
Simply removing the mains tranformer from an LED lighting unit will not necessarily leave you with something that runs on 12 volts, so you will need to find out what DC voltage the unit was designed to run on and than reconfigure to get it to run on 12 volts. Unfortunatel this might not be straightforward but good luck!

 

[Retread]

The easy way would be to use a small inverter if the output of your transformer is anything other than 12Vdc. Have you checked the polarity?

 

[kapt]

Thanks to all for replies. Have checked polarity and now see my assumption that LEDs run off 12v is not necessarily correct. The input driver/transformer shows input voltage 85-265v. I had thought about 12v supply to an inverter, then 220v to tranformer back to (whatever voltage these lights need) lights - but far too complicated.
I am most grateful for your suggestions - I think I will have to try and source alternatives that are designed for 12v. Pity as these are just the job and, compared to ones designed for boats/caravans/Rvs etc. are much more competitively priced - now there's a surprise!