Need Some Ideas For next 2C m@g mod

[Justintoxicated]

It's no big deal, the white emitter's slug is - so it can be connected to the ground without issues. This is how Im running my Lux III and its fine.

I just don't understand why it would be bad to use 3 123's with a buck circuit? Or how this setup would compare to 2C's with a boost circuit. I don't really want to make a special pack to run 3 123's in parallel because I have no idea how to do this.

Thanks,
JI

 

[illumiGeek]

Justintoxicated , if you look at the docs for the Downboy it says that the emitter can not be grounded to the sink. It suggests using an extra layer of thermal adhesive to insulate it. But this would affect thermal transfer.

Maybe I'm being overly concerned here, but my experience with heavily overclocked CPUs has shown that a little too much thermal compound affects temperature. Contrary to popular belief, thermal compounds are not very good conductors of heat. They are just better than air and are designed to fill the voids where device to heatsink contact is not perfect.

For proper heat transfer you need as much device to heatsink contact as possible. When all of the thermal coupling is through compound (no direct contact) thermal coupling is quite poor and the device will run significantly hotter.

Thermal data on the Luxeons indicates a hot Lux puts out less light than a cool Lux, and will have a shorter life (lumen loss). I have a 1W Lux mod that is not very well cooled (small heat sink that gets too hot to touch), and I can see it dimming after a few minutes of continuous use. It seems to recover after it cools down (and I have run it for more than an hour continuously without failure so the cooling must at least be adequate), but I'm sure it will not last anywhere near its rated life.

Maybe I'm just being paranoid here, but my experience with the 1W seems to indicate that better cooling = brighter. Since the whole point of running more powerful 3W & 5W parts is more light, it seems to me that maximum cooling efficiency is a key factor.

Then again, maybe I'm just /ubbthreads/images/graemlins/crazy.gif

Aloha, iG

 

[Justintoxicated]

I understand your concern but again it will not matter much in this case. It probably says that for the converter because the spec sheets for the Emitters and Lux III also says this.

My main concern is the difference between running 3 123's in series with a Bucj Circuit vs running 3 123's in parallel with a boost circuit.. Vs just running 2 C's with a boost circuit.

I need to decide which of these methods is most pratical. No1 has told me what is wrong with running 3 123's in series.

 

[Justintoxicated]

so if I use 3 123's and a DB converter I can pull a constant 1 amp?

or would I be better off uisng 2 C's and BB converter?

Or canone somone maybe explain how I can make a booster circuit myself?

 

[Justintoxicated]

ok well I still have no clue how to get 1amp out of a 2C light, I looked at converter boards and don't see anything designed to be used with 1 amp..

I also don't understand why I should not use 3x123 in series with a buck circuit...

So I really have no clue how to do this. Maybe I should just sell my Lux III and Hotlips?

Does anyone know how to do this?

 

[IsaacHayes]

If you want 1 amp, then you could do 2x123 with a DB 1000. Or you could even do 3x123, allthough I'm not sure how much runtime would be improved, but you'd have extra energy being wasted too.. 2C's with a BB1000 would not stay in regulation long at all, and wouldn't be able to supply 1 amp as the draw on the alks would be way over 1 amp and they wouldn't do it.
Best to post the question in the Sandwich Shoppe forum...

 

[Justintoxicated]

[ QUOTE ]
IsaacHayes said:
If you want 1 amp, then you could do 2x123 with a DB 1000. Or you could even do 3x123, allthough I'm not sure how much runtime would be improved, but you'd have extra energy being wasted too.. 2C's with a BB1000 would not stay in regulation long at all, and wouldn't be able to supply 1 amp as the draw on the alks would be way over 1 amp and they wouldn't do it.
Best to post the question in the Sandwich Shoppe forum...

[/ QUOTE ]

Ok I guess Ill Ask over there, I really want a 2C light I must have one or else Ill have to do the old 3x123 DD a Lux V mod, but I don't have any money for extra LED's right now. But I could put it off untill I mod Lux 5's into my headlights on my ATV...