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how to power a 30w high power led? Answered

i am making a diy homemade projector and i want to know how to power a 30w led without a driver becouse the driver cost 30$ and i want to make the projector as cheap as posible so if anyone know a way to power a 30w led without a driver please help me

the led ......http://cgi.ebay.com/30W-White-High-Power-2100LM-LED-Light-Lamp-Bulb-A_W0QQitemZ220708010099QQcategoryZ163866QQcmdZViewItemQQ_trksidZp4340.m263QQ_trkparmsZalgo%3DSIC%26its%3DI%252BC%26itu%3DUCI%252BIA%252BUA%252BFICS%252BUFI%26otn%3D10%26pmod%3D220693236934%26ps%3D63%26clkid%3D5621333683761900258


Is 10.70 FUSD cheap enough? Here's the link:

Dealextreme is another Hong Kong retail-monger.  Typically these guys in Hong Kong have really good prices, but it takes weeks for the thing I ordered to arrive. Well, I live in the Former U.S. I guess shipping might be faster if you live in a country that is closer to Hong  Kong.

The other thing I was going to say is the stuff DX sells is often cheap in more than one sense of the word.  The comments people leave can be somewhat helpful in determining whether or not any particular item is low-quality junk or not, but truthfully it's kind of a crap shoot, total Monte Carlo,  like Forrest Gump's proverbial box of chocolates.

DX also has the 30W LED @ 23.58 FUSD

Also heatsink grease @ 2.10 FUSD

Also a link to a Youtube video of someone successfully putting these pieces together:

It looks like a heat sink from an old motherboard.  I'm guessing you already have that part, or can scrounge it from somewhere.

18 V @ 2 amps, is a beast. You need around 24V to drive it. A resistor design is probably a bad idea for this - you'll be dumping 12W in the external resistor, but a 3 Ohm 15W + resistor will work. Big LEDs are likely to be unstable on a resistor current limit though. Buying a proper driver is money well spent.

differential opamp to sense the current through a low-ohm resistor. Opamp drives HexFet as constant current source. a PTC and associated signal conditioning to monitor temperature and provide over-temp shut down.

Unless you know what you're doing, it's like Steve said.

With things like this there is little cost-benefit in making a driver over buying one.
Buy the right box for the job.