Hi guys. There are so many different informations about direct driving a SST-90 led, that i just don't know what to believe anymore. I'm thinking about making simple 3D maglite mod with SST90, direct drive and with as little changes as possible. I want on/off. That's all. Some people reported that 3D ni-mh setup even with high quality D cells just isn't enough for gaining current at around 4-5 Amps. I know that internal resistance of the flashlight represents an issue, but couldn't be 4 amp current through LED reacheable? What are your observations and experiences? I would like to make this thing reliable and simple. I don't want an insanely bright light for 10 minutes and then shut it off to prevent LED damage. How much current can maglite switch sustain?
3xD ni-mh SST-90 direct drive maglite
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Fichtenelch
Enlightened
The problem in direct-drive is, that you can't control the current. so, it will discharge your cells at max current, which results in short runtime. with nimh d-cells and high capacity you will have 8.000-12.000 mAh, so you will propably have a runtime of around an hour +/-50%, depending on Vf, If and internal resistance. however, having control of the brightness is necessary, since you can't read in the dark with too much light and there might be situations where you just need a little amount. you might consider having a look at 'derwichtels' driver, sold in the custom b/s/t.
You might need to check if you can reach enough current with 3 nimh cells. i'm also planning a sst-90 3-cell nimh light, but with d2flex driver. i think 3 nimh cells should be enough, since it was enough to kill one of my sst-90's....
You might need to check if you can reach enough current with 3 nimh cells. i'm also planning a sst-90 3-cell nimh light, but with d2flex driver. i think 3 nimh cells should be enough, since it was enough to kill one of my sst-90's....
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PCC
Flashlight Enthusiast
I just recently posted my build of a 3D DD SSR-90. I'm only able to get about 3-5A from three D NiMH cells but four cells goes over 12A and the LED turns mildly blue. I eliminated the standard switch and installed a switch in the tailcap so that I can have a larger heatsink but the thing will still get very warm after only 10 minutes of continuous use. The switch I used has a rating of 10A @ 125VAC. When making a direct drive LED flashlight you need as little resistance as is possible to allow as much current to flow as you can within the limits of the LED's capabilities.
Well, i don't really want to get currents over 4-5A, so i think i'd be able to stay in the "safe zone" without "resistance mods". I'd go with simple resistor if the current would still be to high. How good does stock reflector focus SST-90? Are threre any donuts, artifacts?
bigchelis
Flashlight Enthusiast
The one PCC and Lambdalights VARA2000 use a Rebel deep reflector. It produces a nice intense hotspot, but you can see its not perfect. I noticed that at 5 meters or more it doesnt matter with these anyways, but if you are set on beam being perfect you can check out britelumens SST-90 reflectors made just for this emitter.
You would be able to get more heat transfer to the heatsink if you use a SSR-90 vs. SST-90 because then you can place set-screws to hold the star down really tight.
Also, you need to break in the LED with a couple hours of use then the current magically goes up. YOu may have to drive the LED hard for a couple short 2~3 min cycles to get the current to go up as well. Those were the 2 little tricks me and PCC used to make the 3D/2D copper SSR-90. Oh, and of course get some Tenergy NiMH C or D cells and yes it makes a huge difference. Even when testing Accupower NiMH = Tenergy is better at those 4~8A of current with sSR-90 emitters. tested and proven in a IS Sphere:twothumbs
bigC
How about stock reflector of a normal, incandescent Maglite? Is it any good? Well, since i currently have Magcharger with TLE-300MR-ex where the beam is all funky and strange, but outside, you can't really see all those imperfections
bigchelis
Flashlight Enthusiast
How about stock reflector of a normal, incandescent Maglite? Is it any good? Well, since i currently have Magcharger with TLE-300MR-ex where the beam is all funky and strange, but outside, you can't really see all those imperfections
I tried that too, but I couldn't get it to focus at all.
PCC
Flashlight Enthusiast
This post confuses me. Why go with an SST-90 if you're going to throttle it down? Why not go with a different emitter like an SST-50 or XP-G? Also, even with the Rebel reflector that massive SST-90 will give you a huge hotspot. It only throws because it is throwing so much light out the front that some of it has to come back to you. If you are throttling it down with a resistor then you lose that and you end up with a flood light.
irv_usc
Enlightened
the 90 should run more efficiently than the 50 at those currents. an xpg would be the better choice for throw.
bigchelis
Flashlight Enthusiast
This I have to see to believe:naughty:
A Mag SST-50 at a real 1000 OTF lumens = will throw in the 30k lux range or more with deep rebel reflector.
A Mag XP-G R5 at 1.5A or so w/400 OTF = I think will not throw nearly as much......
Off topic: but has anybody measured the lux on such a build.
SST-90 at 5A is a compromise you can make if your heatsink is not good enough and more current with a production heatsink will result in alot less lumens then you would expect.
bigC
bigchelis
Flashlight Enthusiast
What type of heatsink are you using.
I think for high current direct drive SST type builds you dont need that empty cavity on the bottom.
I think for high current direct drive SST type builds you dont need that empty cavity on the bottom.
Can someone please tell me where to get Maglite 3D Rebel reflector? New version maglites are hard to find in europe, plus they're expensive like hell!
BTW, i don't want to throttle it down 5A is a compromise between runtime, brightness and generated heat. Around 9A everything become somehow "risky":twothumbs
BTW, i don't want to throttle it down 5A is a compromise between runtime, brightness and generated heat. Around 9A everything become somehow "risky":twothumbs
irv_usc
Enlightened
i've searched around and it seems like the only place to get a rebel reflector is to buy a new model light. from a thread on here it seems that if you try to purchase a reflector from Mag directly they will ask for your light's serial number.
Damn, not good...
If you are referring to the 16mm Opening mag reflector shaped op one?
I have tried it & it's about the same a DX P7 OP reflector, actually I think the DX P7 OP was slightly better.
I expect all the regular mag OP reflector to be pretty much the same,
the differences will be minor, unless one is done with a really bad OP job. As they are all the same parabolic shape & OP finish.
The Major advantage of Rebel deep is that it's the only mag size SMO that could give a perfect beam on SST, 30% lux increase is expected when going from OP to SMO.
irv_usc
Enlightened
OP will reduce throw significantly because it scatters the light. i'm not sure how far you are looking to reach?
