18650 direct to an R2??

[JimmerG]

So here's the plan....

I'm currently running a CREE P4 directly from an 18650, with a resistor (don't know what sort I'm afraid)

I've got on of these R2s on order http://www.dealextreme.com/details.dx/sku.15943

Will this work if I direct drive it - with the existing resistor, or will I have to use a specific resistor to get the best out of the R2.

Or do I need to start playing around with drivers - (I don't really understand drivers)

Also as far as I can see there's no heat sinking. There's just a 5mm empty behind the star that is supported just around its edge - no thermal paste.

The torch itself is one of these http://www.dealextreme.com/details.dx/sku.14450

What do you reckon? Can I set the brightness/runtime by using different resistors? Or is it just not that simple....

Thanks for your help.

J

 

[Marduke]

It's the same model LED, so your existing resistor should work.

However, you should consider doing a little more for heatsinking.

 

[JimmerG]

Marduke, you're just always there with the answers when my limited electrical knowledge gets stretched!!

So, that's interesting about the same models using the same resistors, I had no idea it worked like that. When you say same model - do mean they're both MCE?

Do you have any idea how the runtime will be affected?

And this heatsinking - is there an easy way of doing this? - is it just a case of thermal glueing a lump of metal under the star? Or would it be enough to glue the outer edge of the star onto the lip on the aluminium case, this helping heat transfer to the torch body?

Thanks so much for your help.

J

 

[Marduke]

Both models are XR-E (not MC-E). With the same resistor, the runtime would remain identical, but brightness would increase roughly ~41%. You could change the resistor to keep roughly the same brightness but give you increased runtime.