Dummy reference guide to SF A2 modding with MJ led (or 35k 5mm) leds

[AuroraLite]

Krit,

I finally swtich the 35k leds to MJ uncut leds for the SF A2. It is a decision mostly based on reliability, since this light will become part of my regular EDC inventory and I cannot bear in mind that uncertainty/possibility that its output might diminish over time.

The result is just as impressive, more flood this time and remains a significant improvement over the original SF A2.

 

[KevinL]

Whoa.... I was just going to say "hold your decision" because I might have something next week for you.

If you think the 35Ks are impressive.. just wait

But good point, the reason why I am not even modifying my A2 at all is that it is a light I need to depend on. I don't think my own skills are good enough to provide GUARANTEES, compared to the automated assembly lines and extensive testing SF does.

 

[AuroraLite]

KevinL,

Haha...if you have something good up your sleeves, I am all ears(or hands)!
The reliability is a real issue, and I think any SF buyers will acknowledge that when they make their SF purchase. And that is the reason why I have not only one or two A2s with me...before I am bold enough to mod this one.

Meanwhile, I will keep my solder iron hot and ready! :naughty:

Btw, what's the verdict as the best solution for a rechargable A2s? I have read from your cool thread about 'A2 convert', and will the 2x3v li-ion rechargable be the best/safest option? I am still not ready to risk this light with 2xR123 just yet...

 

[KevinL]

You guys will find out the exact nature of the beast next week when I get my first look at it. More than one A2 - you are a flashaholic indeed! The only modded SFs I keep around are my collector's editions. My KL1-SG has a new RY0J LED for example, but my working KL1-HA has its original yellowish LED. Much as I dislike the tint..


Anyway, still driving my A2 on 2xCR123. Regulation helps take away the pain because the light remains brilliantly white till the cells are ready to die. If I think I'll be using the light for extended periods of time, I bring my U2 instead with its 18650 high cap lithium ions.

 

[wquiles]

AuroraLite,

I got my A2 today and as I expected, the "normal" LED's that come with it have that awful "angry blue" tint which I hate so much (too used to the Luxeons, I suppose).

Which of these mods that you have done you feel gives you the closest to true "white" tint? From the pictures I would guess the uncut MJ's, but wanted to ask to be certain.

Will
(A2 ready to be LED modded!)

 

[AuroraLite]

Hi, Will. :wave:

Haha...another A2 modder!

Actually, believe it or not, the 'whitest' I have ever seen is actually 3 26ks Chinese leds put together in a PT attitude mod that I have done. It is like the X0 tint driven at 750. Not warm, not cold, just perfect.

But the only worries I have about is its dimishing output when overdriven as featured in the 'Head to head' thread. And that is why I have went for the MJs, it is a little creamy and a very slight hint of green, but heck, it is such a huge improvement over the original angry blue/purple that it is well worth the effort.

The most 'throw' actually comes from the 35k, but as I have mentioned in the thread, I'd worried about it's long term unknown performance when overdriven at ~80ma, and it is angry blue like the originals. But the beam it so tight that it actually can throw a little.

Btw, I took out the A2 with MJ leds for a night hike in pitch dark, it is really a cool 'tool' since I can identify/see pretty well within 20+ feet with the leds, and the incan could lit up the path if the throw is needed. And for close up work, the leds are really bright and quite comfortable to read with.

Anyway, good luck to your mod, and show us your mod when it is done!

 

[farscape105]

Sorry about being off topic. Have some newbie questions about poor mans A2, the TT 2L. I just have a little experience with mods. Modded a SL keymate with MJLED which is sweet. I put Dorcy Spyder bulb in my TT 2L and would like to replace the 3 led's in TT2l also. Any advice on TT 2L mod? Which would be better Nichia CS or MJLED's? Would I have to put in any resisters or just solder in new led's?

 

[AuroraLite]

Farscape105,

This TT2L project seems to be a fun one, and unfortunately I don't have one to give you straight answers, but...

1) Are the original leds setup parallelly or in series?

2) Are there any resistor(s) soldered with each/group of the leds? What are their/its value? And how are their setup(one resistor for each led, or one resistor to a group of paralleled leds, etc)?

3) MJ is a bright flood of light(mine has a very small hint of green/yellow, but overall it is a huge improvement on the angry blue tint. But if you like more 'throw' or concentrated beam, seems like the Nichia is a better choice. And depending which one you like better, we might have to solder in a resistor(SMD or regular, depending the room we have) in the mod if it is directly driven by the 2 Li batteries.

 

[wquiles]

AuroraLite,

I am almost ready to modify my A2 - I am too tired of the angry blue tint!.

Some additional questions:
- Regarding the LED's, how are they wired? Series or parallel?
- Assuming parallel, are the batteries (2x3V) driving each LED individually with a current limiting resistor?
- You mentioned 40ohms above for the MJLED - what was the stock value?

Thanks in advance,

Will

 

[AuroraLite]

AuroraLite,

I am almost ready to modify my A2 - I am too tired of the angry blue tint!.

Some additional questions:
- Regarding the LED's, how are they wired? Series or parallel?
- Assuming parallel, are the batteries (2x3V) driving each LED individually with a current limiting resistor?
- You mentioned 40ohms above for the MJLED - what was the stock value?

Thanks in advance,

Will

Hi, Will.

The original leds each has a 33.3 ohm resistor soldered in front, and each set of resistors and leds are wired parallel with each other.

The spec of the 'uncut' MJs are found as the 5mm 100ma as in the following ISP:

http://www.powerleds.com/

Thanks to Wayne(btw, can you tell I am a total dummy in EE), he had told me the sweet info about these leds, and that it might have degradation as shown in 'head to head' thread if we go above or close to 100ma.

Earlier in the thread, I had the calculation as ~90ma to each of the MJs(assuming its Vf is around 3v)in theory.

Yet, I had recently ran a very identical setup of 3 sets of MJs and each as a 32ohm(22+10) in front of it, on a bread board.

Driven by 4x1.5v(6.2v measured) alkaline, IIRC, the numbers of ma was much smaller, something around 50ma to each MJ. Certainly, a 2x123 probably might yield a higher current, but it is more likely that the current should still be within the safety limit of 100ma.

And that was what I did to my swap, just the MJ leds with no change on the resistor values. So far, after a few sets of batteries, it continus to work like a charm.

Good luck to your mod!

 

[FredM]

So the anode ring is no longer used? How is it originally attached to the LED ring? Solder points?

Once the anode ring is off further swapping of LEDs in and out will be easy correct?

 

[wquiles]

OK, so I just finished my own A2 LED upgrade thanks to AuroraLite :bow:

I went from a nasty case of really angry blue LED's to a creamy, white, close to X1 tint (a hint of green), and on top of everything, they are no longer seriously over-driven.

Here are some pictures of me playing with the stock LED module against a white background. It is hard to tell from this picture, but the angry blues are really nasty!

I first try with some Nichia LED's from the 2nd group buy, but these still have too much blue on them:

I then try the recent 35K LED's that I got from here in the forum (thanks KevinL), and these were much more white, almost perfect. Although the picture shows then different brightness, the truth is that the beam/angle is different on both and that is why the 35K's look dimmer than the Nichias, but they simply have more trow:

and for those who have not open the A2's head, it is pretty impresive on the inside:

I made a lot of current & voltage measurements and found that the A2 is seriously over-driven (in my humble opinion). In order not to hijack AuroraLite's thread, I am starting a new thread on the LED area just to talk about the drive levels in these LED's and my findings.

Thanks AuroraLite for inspiring me to modify and improve my A2 :bow:

Will

 

[js]

wquiles or AurorLite,

What is the best, safest, and gentlest way to remove the LED ring from the head once you remove the three screws? I started to try to get the ring out of my HA BLK A2 last night, and it wouldn't come out easily, so I decided I had better wait for some advice. I'm not in any hurry here, and I have the utmost respect for my two A2's.

So I await your advice! TIA!

 

[wquiles]

Jim,

Yes, it is a tight fit due to the LED's. It has been a little while, but I think I just used some strong thin pliers and pulled straig up. It is very hard to break anything

When you are done putting new LED's/resistors, they LED ring will also go back with some force. Tight tolerances I guess

Will

 

[js]

Where on the ring should the top and bottom jaws be aligned? Anywhere on inside and anywhere on outside? Or from a screw hole to the inside? Or what?

 

[wquiles]

I am pretty sure I used one of the screw holes along with the inner (main lamp) hole to grab the module.

You will be fine. Just go slow

Will

 

[js]

Thanks, Will! I'll give it a try.

 

[AuroraLite]

Hi, Js and Will. :wave:

A little late to the party, but I could confirm I too do use the same method to pull the ring out(thin pillers grabbing by the screw hole and main bulb hole)

I think part of the reason is because of the leds catching itself onto the led holes. Wiggle the ring a little while pulling it out should do it.

 

[Arkayne]

Time to bump the thread!

Do they have those high mcd LEDs in RED? I'd love to do this mod!

 

[AuroraLite]

Arkayne,

Thank you for the bump.

Hardly use the red leds, but I shall look around and if I find anything, I shall let you know.


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Meanwhile, I have been struggling for the longest time--should I or should I not to mod this A2 into a Lux light(while keeping the 3 seperate 5mm in a different color)?

Right now, after much thinking and talking to others, the light seems to be rather perfect by itself, and there is no real urgert to mod it. But the debate continues when it comes to the reliability issue of a bulb(and replacement cost) vs a lux....

What do you guys think?