Heat, Downboy and 5-Watt

[akula88]

I have two 5-watt(ers) on my collection -- SF L4 (regulated ~700ma) and TnC HyperLux V (direct drive). However, I find limited runtime and usage for both, since I would have need them to have an extended runtimes. This is due to the heat generated by the luxeons, making the whole body -- "too hot" to handle in a continuous 5-min run.

Is it possible to use Downboy and have them regulated low enough, but still enough for the 5W to be bright? At what current should they run to minimize heat? DB at 500ma? DB at 400ma? /ubbthreads/images/graemlins/frown.gif

Thanks,

 

[Kiessling]

To use a DB with a 5W you'd need 3x123 since the voltage of the cells needs to be superior to the Vin of the LED (buck converter).
I am running a 5W LED at 500mA in a PR-T and the heat-issue is fine if I hold the light in my hand while constant-on. It sure gets hot, but you can easily hold it, at least I can. ( I am a wheenie FYI).

If you'd want 2x123 a BadBoy would be your ticket, and this head could also be used on 1x123.

bernhard

 

[ErickThakrar]

Uh... I didn't think you could use a Badboy on 2XCR123s?

 

[TrueBlue]

If I remember right the Badboy will work with up to 9-volts. I think a Downboy (buck converter) would be more to your liking and more efficient too. I have a theory that it is easier to drop a heavy package than it is to lift one. It is easier and more efficient to lower a higher voltage than to lift the lower voltage to a higher energy state. I'm working on a hobby/project right now to see if it is true.

I think a Downboy would be better suited for 2 CR123A batteries. A Downboy at 500mA would be good.

 

[mut]

The BB can be used on a 5W on 1x123 and 2x123 because of the Vf as bernhard had stated previously. The Vf of the 5W is around a T such as a WXO(T) take a look here for the bin codes explained.
One of my most favorite heads is a 5W WXOT BB/833 on a 1x123 body.

Hope this helps.

mut

 

[akula88]

Thanks all.
Bernhard> I think BB will be applicable for the KL4, HLV will have to be DB since it is a 3-cell light. BTW, I planned to use Pila 168 on KL4 and 2xPila150 on the HLV.

Supposing I will have the HLV regulated at DB500 or DB400, will this affect the tint of the light? Some CPFers are suggesting that 5W need to run at least 700ma for a full tint. Any verifications?

 

[cy]

Another vote for BB750 with 5watts. Both Xbins of mine are driven by BB750.

just came back from walking my dog for 25 minutes. I ran X4T PR-T 1x mclux body w/R123 li-ion. it barely got warm. these new R123 li-ion are the bomb. starting voltage was 4.19v. ending at 3.85v after running aprox. 20min. Very bright output!!

 

[BigHonu]

I have a DB750 in a PR-T running on 3x123. Gets pretty damn warm, even if you hold it in your hand the whole time. YMMV

 

[Kiessling]

yes, tint will be slightly "warmer" when underdriven.
but it is not that bad, it is the same as with the LuxII LEDs.
The only thing to rpevent this from happening is the use of a PWN driver.
bernhard

P.S.: I prefer a BadBoy with the 5W because it gives you the pobbibility of 1x123 and 2x123 use

 

[wptski]

[ QUOTE ]
cy said:
Another vote for BB750 with 5watts. Both Xbins of mine are driven by BB750.

just came back from walking my dog for 25 minutes. I ran X4T PR-T 1x mclux body w/R123 li-ion. it barely got warm. these new R123 li-ion are the bomb. starting voltage was 4.19v. ending at 3.85v after running aprox. 20min. Very bright output!!

[/ QUOTE ]
cy:

Where did you get the new R123 Li-Ion from? I didn't think that JohnB got his order in yet unless you got some samples?