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What do I need to "run" these LEDs

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Dr. Strangelove

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Hi Guys, thinking of putting together a (hopefully) rather bright torch from LEDs (like these **broken link removed**, if there are better options please feel free to suggest them :)).

They will be powered by batteries (number and size not decided), now some places write that you need a "driver" to use these LED's if thats the case how would I go about making one to run something like 5-6 of these? Or can you just use a couple of resistors?

Also says they need a heatsink... but how do you "mount" a heatsink on an LED?

Sorry I know very little about these things.

Thanks
Jacob
 
You can use a resistor but a driver is more efficient. You can get special ICs or modules to drive this LEDs or you could design your own circuit.
 
The simple way is to use a series resistor but it's inefficient because lots of heat is wasted in the resistor. It can also be more expensive than a more complicated switched mode supply because at high power levels a large resistor is required which requires a large heatsink.
**broken link removed**

[latex]R= \frac{V_{SUPPLY}-V_F}{I_F}\\
I_F = \text{Foward current}\\
V_F = \text{LED forward voltage}\\
V_{SUPPLY} = \text{Supply voltage}
[/latex]


An efficient but more complicated way is to build a switched mode power supply.
https://www.electro-tech-online.com/custompdfs/2008/08/slyt084.pdf
https://www.electro-tech-online.com/threads/led-switching-regulator.41375/

The easy way to do it efficiently is to buy an LED driver module.
**broken link removed**
 
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Here's a led wizard to help you: **broken link removed**

It'll show how to wire series/parallel with proper resistor.

edit: It only shows how to use resistors in the circuit, ther are other ways, most of them more efficient than resistors, but this give an idea how they work.
 
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The LEDs are made in China (Cheeeeeap!).
Nobody knows how they are mounted on a heatsink and nobody knows how many minutes or seconds they will last before they fail.

Philips Lumileds have all the details in English.
 
So efficiency sounds good to me as I will be running the LED's on battery power. If I build a driver like the one you linked to Hero, would I need to make one per LED (assuming the LED draws 350mA-700mA like these **broken link removed**)? or would one be enough to drive more than one?
Thanks
Jacob
 
It depends on the driver, it's possible you could connect all six in series and just use one driver if you chose the right one.
 
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