what current is your modded Arc?

[Robocop]

I am about to have my Arc modded for the second time and I am going to a 3 watt Lux.I have the stock board bumped up to 667 MAh and I am considering increasing this number if possible.Can anyone tell me what the max current available on a standard Arc Ls board is?...Also what are some of your boards set at and how do you like the specific current?
This may should have been in mods section however it is specific to Arc boards so I hope this is appropriate.
Heat is not an issue in this as this light is a back up only for me on duty...if used at all it will be for very short times when my main light is not available.I know at 1 amp a 3 watt gets very hot however my current set up(Q3J at 667)also gets warm....I appreciate any feed back and thanks again...

 

[markdi]

I am interested in this too.
I put a twoh in my arc ls.
will doubling the current give me twice the light ?
I have read posts indicating that the light dim's or has other problems after increasing the current draw.

 

[shiftd]

it is not really worth it to increase current in the original arc since it is becoming more and more inefficient as you increase the current. even at its stock, 343 mA, its efficiency is less than stellar. But if you insist on increasing the current, i believe in theory you can increase it as far as the smallest resistance you can find. you can stack however many resistance too. There is a limit, i am sure, but i think you can hit 1000 mA, though efficiency will suffer a LOT. Heat should also be a consideration. If you are talking about stock LS rev2, bumping current a lot higher than its stock will sure to cook, if not fry the lux, as its thermal path is not really that good.
just remember, doubling the current will NOT give you twice the brightness. more of like less than 1.5 times the brightness, when you overdriving it.

 

[Robocop]

I also remember reading a very interesting thread here on the limit as to what a single 123 cell could also support.I know there must be limiting factors involved with this set up however I am mainly attempting to know what the actual board will support.I may be a little confused here as to why the output would not increase with the current...the 3 watt is said to be at its best at about 1 amp or a little higher.Will I notice any difference if it is ran at 667 VS 900 MAh?
My reason for this is that I have searched several posts before posting this question and I have noticed many varied set ups with modded ARCs.Many have their lights set at 667 while others use 750 or even 900 MAh.If I will not really notice a difference with an additional 200 to 300 MAh I am not going to change anything other than the emitter and add a reflector.I was mostly concerned with losing some of the tint when underdriving a 3 watt as I have read this sometimes happens.
This light is going to be used as a back up light and it is rarely used but when it is I will hope for maximum brightness over runtime.LitFuse has been a big help with my questions and he does some amazing work.I would however like some opinions on the various configurations from actual real world experience.
Thanks again for the help on this....and yes I do know that I tend to over analyze everything but I like to research all options before I send out my well loved ARC for surgery..hehe

 

[shiftd]

alrite, let me try if i can illustrate some thing.
i have not pumped my arc to more than 667 mA but i did try driving one lux at 1 amp, 750 mA and 400 mA. to be sure, each additional miliamps added will increase brightness. if you double the current, it will be a lot brighter than before, but not twice as bright. this is because any lux, when you overdrive it, will become less efficient in converting power input to lumens. going from 667 mA to 900 mA (notice, it is mA: current, not mAH, which is capacity) will surely net you in an increase in brightness and you can be sure notice the difference in brightness. but that additional brightness is not (900 - 667)/667 times of increase over the previous brightness, rather, less than that. Going from 667 mA to 750 mA might not give you any noticeable increase, however, unless you are comparing side by side.
when you underdriving 3W, yes, you can notice some tint changes as it tends to go toward green/yellowish. but at above 500 mA will give you a pretty good color and very little tint change compared to 667 mA.

i hope it clears something up rather than putting you in more mud of confusion /ubbthreads/images/graemlins/tongue.gif /ubbthreads/images/graemlins/icon15.gif

 

[Robocop]

Shiftd I do appreciate the imput here and yes it does help to clear it up for me now.I have noticed that some prefer to mod the ARC board like with Litfuse mods and some others use an entirely different board such as most of the mods by Jets22.I am still wondering what the max anyone has been able to push their factory ARC board to.I feel that I am stuck in that line of thinking that more mA always equals more light.
I feel that if the stock board will safely support more than the usual 667mA what would I lose other than runtime.I do understand a little about actual perceived brightness in concern to luxeons and have learned through past posts that a small increase is hard to notice at times.
I think my main concern is with the tint.I have also read many posts that say a 1 watt driven at specs can be every bit as bright as a 3 watt that is underdriven.I am hoping to get as much as possible from my next mod and feel that if 667 mA is sufficient I will leave that part alone.
I do appreciate the experience and advice on this and I will keep you posted of what I decide to go with...regardless I am sure I will enjoy my newly modded light.

 

[shiftd]

personally, i love to use completely custom (well, not THAT custom, as I still use the good ol' BB, but one is really custom) like the jarhead's circuit like link

This is an older mod that i did about one year ago (damn, time sure flies, doesn't it?) hope that gives you some inspiration.

See, going to completely new circuit gives you LOTS of possibility. You can use dat's new wizard, 1000 mA output, or even DB and/or MM & BBs. If you stuck with the original arc board, do not be sad. it is still a nice piece of thing, especially if you have the older model, where you can run it from 1AA alkaline (a huge plus, but nothing near as good as a madmax /ubbthreads/images/graemlins/tongue.gif).
depending on your intended use, 650 mA will suffice, most of the time. well, if you need it for blinding assailant, why go with the puny arc to begin with anyway, right?
1W driven at spec might overperform 3W at the same current (up to 350 mA), but not much difference, while 3W at high current will certainly overperform 1W at the same current, no doubt about that. If you indeed go with higher than 667 and 3W lux, go with 750 mA, since 700 mA is the lux3 rated current at spec, and going a bit higher than 700 mA will guarantee you that the lux is running at spec. Again, it all depend on your need.
one more point i need to make, given the arc's efficiency, i think there is no point to go to 1 amp. the battery simply cannot support the current for a sufficient amount of time.

well, all of these sound complicated (they are to me /ubbthreads/images/graemlins/tongue.gif). GO custom!!! /ubbthreads/images/graemlins/grin.gif

 

[cy]

Robo, heat is a concern when running at 1amp. Yes it will be brighter, but as heat built quickly. Output drops in relationship to the die temp.

What I would do is try out an R123 li-ion before modding your LS again. You will be amazed at the output difference. I've been getting aprox. 1amp draw from R123 cell, so aprox. 850 milliamps to lux.

Also to answer you tint concern. In most cases of inserting a li-ion into an ARC LS the tint has improved.

This is some risk from doing this. But so far no one has reported any damage to an LED light from using R123.

Please post, if anyone knows differently.

 

[Hallis]

Robocop. I agree with shiftd about going with an aftermarket board like a BB. Cy is actually working on quite a nice little setup for using apready existing boards in a rev2 LS body. All my Arcs are stock. the only one i have close to being modded is my 500 brown board hybrid which was modded from the factory. It delivers 413mA, (500 reported). It is noticably brighter than my other first run.

But i suggest not modding the LS board any further. Get yourself a BB or MM or some other nice regulation board.

Just my opinion. /ubbthreads/images/graemlins/smile.gif

 

[LitFuse]

Robocop- I think 667mA, or maybe even 611mA, is the sweet spot for the Arc. I have done a couple at 833mA in early mods, but don't recommend it anymore. There are several reasons-

1. It gets really hot really fast.

2. It really isn't much brighter.

3. The cell can't really handle the draw very well and the light may not run in regulation.

The Arc is a pocket light, and in the 600mA +/- range, a very impressive one. If you need more output, I would recommend a larger light.

Peter

 

[Robocop]

I am beginning to understand a little more and I do appreciate all the comments.I did not know that 700mA was the recommended level for the 3 watt.I believe I will keep it where it is and maybe try the R123 li-ion that cy spoke of.The light I have now is beautiful and has served me well many nights on duty.The total output is amazing however the tint is creamy yellow and I now find myself wishing I had a different tint.That is why I was mainly worried about the current as I wanted to get the most from my 3 watt but if it is rated at 700mA then it should be fine as it is.
I do like the idea of another board and have never considered this as an option.So many decisions and so many good products to use make it confusing at times.I am pretty sure I will leave it set at the level it is and see how I like it.I have read many here who have the 3 watt at 667mA and I do not recall ever hearing of anyone who was not happy.I believe there is also a limit as to what a single cell can push and this may be a good setting for a one cell light.
Cy is it possible to buy a single R123 cell to try in this light?I have not kept up with any of the threads on the Li-ion cells as it has never been a concern for me.If I am thinking right the R123 is simply a rechargeable version of the 123 correct?

 

[Hallis]

It's Lithium Ion, it delivers 4.2v totally charged as opposed to 3v like the ones you can get from surefire and battery station. That should be considered when using them as replacements. I wouldnt reccomend them for your purposes, If you were to get an aftermarket converter then the LiIon r123's would be perfect for you. I have 3 of these cells and i use them in my Arc4+, But it was designed with these cells in mind and can handle the increased power because of its more advanced electronics.

 

[Robocop]

I have sent my

 

[Robocop]

I have sent my

 

[Robocop]

sorry hit the send button by mistake....I have sent my light to Litfuse and I am going to keep the mA setting it is set at now(667mA) however I am replacing the Q3J with a TXOJ 3 watt emitter and adding a reflector and UCL lens.
I have searched and can find no beamshots or any other information on this configuration.Does anyone here have any information on this particular setup?...maybe how hot does it get...run time...or even what is the difference between the Q3J and TXOJ when both are ran from 667mA?
I would love a beamshot however my searching has not found much luck here.I am most excited about the addition of the reflector.I have a few lights with this reflector and my friend Owen has one in his LongBow.The difference is incredible and I am sure it will be beautiful with this ARC host and LitFuse as the modder.He really does some great work and I am now planning my next ARC creations as I am working on a trade for 2 extra LS lights....wish me luck and thanks for all the information.

 

[markdi]

what resistor value do I need to bump my arc ls rev 2 up to 667 ma ?

and where do I get one cheap ?

 

[cgpeanut]

First off these are not for sale, I'm giving them away as christmas gifts to family and friends /ubbthreads/images/graemlins/grin.gif

I find my sweet spot depends on the bin of the lux I'm using , TWOJ@333mA is nice and bright and runs longer and the tint is white, good for EDC. TXOJ@500mA I did to minimized the blue ring it's still there but a bit thinner and less noticeable I like it /ubbthreads/images/graemlins/smile.gif TXOJ@667mA I find gets hot quickly so it's seldom used It's not really practical IMHO because you use the battery up rather quickly.

Here's some beamshots I did a few months back when I had the TWAKs.

left TWAK@333mA right TWOJ@333mA

left: TWOJ@667mA right TWAK@667mA

These hae the IMS sa17 reflectors and UCL lens.

Hope this helps.

 

[markdi]

nice lights-great pictures-kool.
I have a twoh in my arc ls rev 2
so would upping the current to 500 ma be better than the 667 ma mod ?

twoh emitter has lower forward voltage than thet-j emitters
so less voltage means less power and less heat.

what do you get for runtime at 500 ma
and at 667 ma ?

what is the value of sense resistor for 500 ma
and 667 ma ?

 

[LitFuse]

It depends on how you're going to use your light. 667mA is fine for intermittent use, not so good for continuous use if battery life is a primary consideration. 500mA is a conservative overdrive that balances good brightness with good runtime. I've been doing quite a few lately at 611mA too, which is a bit brighter, but keeps the heat down a bit and should last a little longer per battery.

I don't know about the various runtimes, but you should get at least an hour per cell at 667mA.

For 667mA, you need to add a .15 resistor. For 500mA, remove the stock .15 and replace with a .10

Check out the resistor calculator at the shoppe.

Peter

 

[cgpeanut]

markdi,

TWOH are nice, have any more to spare? /ubbthreads/images/graemlins/grin.gif

I think the lux and the arc-ls pcb would be very happy at 333mA but if 500mA you want change r1=.22 r2=.18 will give you .5051 mA

or go to this web page and plug in your desired current.

http://www.anlighten.com/shop/test.php