Is it possible to make a Luxeon K2 W501 sidelight bulb?

CTR

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Aug 3, 2004
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I'm thinking of making one, but I'm no good with the electronics. All I can remember from school days is V=IR this was over 12 years ago so please advise where I am wrong :)

This is my best guess.

The alternator on a car gives out between 12-14V DC, the K2 needs a voltage of 3.4V and a current of 350mA. So doe that mean I require a 3.4/350x10-3 = 9.7ohm resistor?

I guess there are different power ratings for resistors, how do I figure out which one I need?

I know I would need to provide some sort of heat sink, will the K2 require a large heat sink? Or can I get away with a very small aluminium block?

Any advice would be much appreciated! :)
 

chesterqw

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singapore,jurong
hmm... you use the P=IV
P=3.4x 350
P=1.190Watts.
you sure you want to run just 350ma for the k2? it can be up to 1500ma. halfing it to be safer at 750ma.
 

evan9162

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Boise, ID
You're going to want to use a proper regulator rather than a simple resistor for a car electrical system. A car's electrical system is a dangerous place for electronics. There's tons of noise from the alternator and ignition systems, not to mention electric motors on windshield wipers and whatnot. Spikes can go as high as 50V, and the load dump from the starter motor can reverse things momentarily to -40V.

What you'll want is a regulator, blocking diode to prevent reverse voltage, and a zener diode to clamp overvoltages, plus an input cap to filter noise.
 

CTR

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Thanks guys.

I guess with all those diodes, resistors and heat sinks to cram into a tiny bulb its not really possible to do. Oh well, nevermind! Thanks anyhow! :)
 
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