LED's? resistance and applications

[armyphil]

I saw a thread on here the other day about using LED's for the number plate light and possible side lights.

I just wondered if anyone could tell me what board i would use to mount the leds and resistors and also the size of the resisitors i would need to use to get them to run on 12 volt?? Plus would it be the same for all applications in the van i.e side lights and dash bulbs.

As you can tell electrics isn't my thing

Thanks in advance phil

[CovKid]

LED should have some info with it. Use this to calculate resistor needed: http://led.linear1.org/1led.wiz" onclick="window.open(this.href);return false;

I'd use 13.5v as your source voltage as it can often be about that at times. They do vary from LED to LED but you'll probably get away with the same resistance for each.

[Oldiebut goodie]

You don't need any boards - just break the glass out of an old bulb and use the body to create your new one - that's how I did mine.

[CovKid]

Yep I did that with my front parking bulbs. Basically break the bulb and hollow base out, push the resistor down into the bulb base, heating the solder until wire pokes through then trim off. Solder LED (correct way round) to other end of resistor and other leg to side of bulb base. Bit fiddly but can be done. May be easier to buy the smaller ones ready to fit in ebay but you can save a quid or two making your own for sure. 10mm LEDs are good for sidelights I found.

[armyphil]

thanks for all your help will be i be able to do the same kind of thing for the number plate light??

[armyphil]

thanks for all your help will be i be able to do the same kind of thing for the number plate light??

[asahartz]

IIRC I use 560ohms for this purpose. However I only use LEDs for interior lighting; using them for any form of road lighting is not legal as such lights must be E marked - they would not pass an MOT. The main problem is that LEDs are strongly directional - unlike filament bulbs which emit light in all directions. So unless the reflector is specifically designed for use with the LEDs, they will not spread the light enough.

[Oldiebut goodie]

It is easy enough to make the array so that the leds point in various directions so that it is not a single beam (difficult to achieve anyway) The majority of lenses diffract the light anyway via the inner surface without the need to angle the leds towards the reflector.
I have never had my led 'bulbs' queried on an mot let alone had them check the bulbs for ce markings - I understand that they are not allowed to remove anything such as lenses as part of the mot check. (in fact I have never seen a bulb with a ce mark either - maybe my stock in my rescued parts predate your new-fangled ce marking))

[CovKid]

There are already some ready-made generic number plate LED lights available these days although I did a WIKI article showing how it could be done with existing fittings. Always worth checking WIKI.

[armyphil]

I did try a search i found the article the other day and wanted a go at doing it but couldnt find it again Wiki i have a poke thanks