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Thread: SST-90 Mag 2D aspheric build, low resistance, direct drive

  1. #1
    Flashaholic* Techjunkie's Avatar
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    Default SST-90 Mag 2D aspheric build, low resistance, direct drive

    I received my 4500K SST-90 emitter from Avnet today. The packaging was laughable. It came in a box about the size of a shoe box. Buried under much bubble wrap was an anti moisture bag with very specific handling instrutions. Within that was a large bag of dessicant, a moisture indicator card and finally what I'd call a jewelry box if it was designed by the military.

    I used Jo's BrightLumens deluxe SST-90 Mag D heatsink. It does the trick, but having done it once, I'm not looking forward to doing it again. I can't think of a better way to mount the emitter, but it was nerve racking working on a $50 LED that's so delicate and so hard to mount.

    I used the fattest wire that would possibly fit through the holes, 20 gauge stranded copper, and ran into trouble getting the fitment right. I had the emitter heatsinked by resting it upside down on top of the jaws of my vise, and that made the solder cool immediately on the pads. The thick pos wire was encroaching on the space of the center just a hair, but it was enough to cause it to sit improperly in the heatsink. My iron wasn't hot enough to melt the solder again and in the end I carfully used a dremel with a cut-off disc to shave back some of the solder so it would sit right. The other complication is getting the thick wire laden with solder bent just the right way to position it so it goes straight down the hole from the corner of the LED. Pics below explain it better than I can here.

    I used AAA in the wire troths and Arctic silver thermal adhesive under the main pad. Adding the AAA to heatsink the wires to the HS is something I always do to improve thermal management. It's that much more surface area to transfer heat with.




    As for reflectors, I did what I usually do and searched for the cheapest possilble solution. I experimented with the DX P7 reflector (sku 12229) and managed to make quite a mess of it with the dremel. Even more scary than the soldering, I had to use the dremel to cut a camphered edge to the inside of the heatsink after the emitter was already monunted.



    The DX P7 reflector actually gave a much better (tighter / more intense) spot than the KD V2 reflector that I opened to 16mm. I had to raise the heatsink about 2mm to get the short DX reflector to focus properly. I was surprised to see a spot about the same size as given to the smaller MC-E emitter by other 53mm reflectors I've used for MC-Es.



    I played around with some other refelctor/optic options, but I'm not done yet. I tried the 40mm+ deep reflector that comes inside the Mag 2D LED after cutting off the cam and opening the hole to 16mm. That gave the best focus yet, but I couldn't screw the head down passed the O-ring. If I cut the lip off the heatsink, I might be able to drop it down the tube until it sits on the Mag switch. That's about a half an inch, which might be just enough to make that reflector fit.

    I tried the KD aspheric but what I found to be even better (much to my surprise/delight) was the $4 DX aspheric sku 12834. It's glass, not plastic, only 18mm deep and while it does not perform as well with the CREE XR-E, it seems to be better suited to the SST-90. Perhaps the difference in the domes affects the performance with the optic.



    Oh, by the way, until the Sector_Cleared driver is available, I'm running the emitter direct drive on 2 parallel Sony 26650VT with a slapped together carrier that I described here.



    I had to add copper braid to the tail spring. Tailcap mearurements were only ~3.5A on the bare spring, but over 7A on the braid. The Vf of the emitter drops as it heats up, but the batteries sag after use. The highest I've measured so far at the tail was 7.95A. The warmer color SST-90 must have a pretty high Vf. Also, I tried some slightly used NiMH C cells. Three yielded a 5-6 amp draw and with four cells current draw shot up to 11A before I quickly disconnected the leads. Maybe a 4s2p pack of AAs might be the direct draw sweet spot for the SST-90, assuming 2pAA sags more than 1C. I may just have to find out.

    (update: after replacing the spring/braid with a cut down "golden" mag spring from KD and using deoxit on all the contacts, I'm measuring 8.5A draw at the tail and 8+ through the spring)

    Until some of my other cheap reflectors come in, I'm keeping th DX aspheric in it. It's freaky fun - much larger and also more intense than the KD Q5 + Aspheric kit. I'll add beamshots later this week.

    Update: finally experimented with 4s2p AA - see post # 25 below
    Update #2: New reflector experiments. Stopped-down photos show improvement with a reflector that actually fits, post #28
    Update #3: the experimentation and aggressive burn-in has significantly reduced the Vf of the emitter see post #31
    Last edited by Techjunkie; 03-11-2010 at 05:44 PM.

  2. #2
    Flashaholic* Dioni's Avatar
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    Default Re: SST-90 Mag 2D build in progress

    Great!

  3. #3

    Default Re: SST-90 Mag 2D build in progress

    Can't wait for some beam shots.

  4. #4

    Default Re: SST-90 Mag 2D build in progress

    beamshots!

    I'm hoping to build something similar when my parts come in. I'm a little nervous about not using a driver...

  5. #5
    Flashaholic* Linger's Avatar
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    Default Re: SST-90 Mag 2D build in progress

    Quote Originally Posted by netprince View Post
    I'm a little nervous about not using a driver...
    Practice man, practice. Try it out a few times with cheaper emitters and it may easy your mind.
    What might also be helpful is to deliberately sacrafice one, overheat it and see it turn blue and ... depart this land of lumens
    YYMV
    experience is great if you can afford it
    Last edited by Linger; 01-07-2010 at 05:29 PM.
    Installing Quantum Tunneling Composite (QTC) into M@glite Solitare

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    Default Re: SST-90 Mag 2D build in progress

    Quote Originally Posted by Techjunkie View Post
    I tried the KD aspheric but what I found to be even better (much to my surprise/delight) was the $4 DX aspheric sku 12834. It's glass, not plastic, only 18mm deep and while it does not perform as well with the CREE XR-E, it seems to be better suited to the SST-90. Perhaps the difference in the domes affects the performance with the optic.

    Until some of my other cheap reflectors come in, I'm keeping th DX aspheric in it. It's freaky fun - much larger and also more intense than the KD Q5 + Aspheric kit. I'll add beamshots later this week.
    Hey Techjunkie, Just wanted to say I am also a big fan of the inexpensive DX aspheric lens. I also prefer it over the no longer available KD aspheric. The image that the DX lens throws up is a bit brighter and to my eyes a bit warming as if there is a slight color shift? I even prefer using it with the CREE Q5 R2. The DX lens also has less side spill ( I wanted to call it flood but that is really not what it is ) than the KD lens. Currently I am working on a SST-50 build. When complete it will be time to play with the aspherical lenses again.

  7. #7
    *Flashaholic* wquiles's Avatar
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    Default Re: SST-90 Mag 2D build in progress

    Cool project. Looking forward to beamshots as well
    Please no PM/Visitor Msg's. Email for questions/Paypal: wquiles [at] gmail {dot} com

  8. #8
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    Default Re: SST-90 Mag 2D build in progress

    The contestants (again). This time with a new addition, the WF-008 recoil thrower. It seemed only fair to include it, considering the aspherics here and the 450ft target tree in the distance shots.



    This time, white balance is set to Sunlight aprox. 5200K for all shots.

    Indoor settings: ISO 200, 0.4 Sec, F4
    Outdoor settings: ISO 200, 4.0 Sec, F4

    00.


    01.

    02. <--This is the 4500K SST-90 being discussed here.

    03.

    04.

    05.

    06.

    07.
    Last edited by Techjunkie; 01-18-2010 at 08:51 AM. Reason: better beamshots

  9. #9

    Default Re: SST-90 Mag 2D build in progress

    the dx 50 mm lens are true aspheric lens or are sferic lens?
    custom flashlights:2 x MTE sf-15 SST-90@10amp,,romisen rc-g2 q5bin ez900chip aspherical and sku7882 @2.75 amp 18000 lux@1m, tiablo collimator with q5 ez900 chip @2.95 amp 72000 lux@1m. pc: e8400/gtx 285

  10. #10

    Default Re: SST-90 Mag 2D build in progress

    Hey Techjunkie,

    How's the color on that emitter?? Compared to the MCE, is it closer to 5A tint or WH?

  11. #11

    Default Re: SST-90 Mag 2D build in progress

    Hi Teckjunkie,

    Nice work, I lile the 2 imr cells to boost the amperage.

    I realize this thread is mostly about your SST mod, but what is PVC on the end of your first light for? A coupler I am guessing, did it fit right on or did you sleeve it somehow?

    Thanks for sharing.
    In Him (Jesus Christ) was life; and the life was the light of men. And the light shineth in darkness; and the darkness comprehended it not.
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  12. #12
    Flashaholic* Techjunkie's Avatar
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    Default Re: SST-90 Mag 2D build in progress

    Quote Originally Posted by netprince View Post
    Hey Techjunkie,

    How's the color on that emitter?? Compared to the MCE, is it closer to 5A tint or WH?
    Closer to 5A. The closest I've got to it tint-wise is my XX-Ray, which uses 4B tint MCE. That's exactly what I was expecting, because the 4B is in CREE's neutral white group (adjacent to 4500K on that chart) whereas 5A is more toward their warm white group (although not quite in the 3000K range of 7A) whereas WH is at the warm end of their cool white group (~5500K).

    I expect that the 5700K SST-90 is a pretty close match to CREE's WH tint.

    After experimenting with neutral white tints, I was immediatlely hooked, which is why I went straight for the highest bin 4500K (GM400) instead of the 5700K or 6500K tints.

  13. #13
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    Default Re: SST-90 Mag 2D build in progress

    Quote Originally Posted by vestureofblood View Post
    Hi Teckjunkie,

    Nice work, I lile the 2 imr cells to boost the amperage.

    I realize this thread is mostly about your SST mod, but what is PVC on the end of your first light for? A coupler I am guessing, did it fit right on or did you sleeve it somehow?

    Thanks for sharing.
    Ha! That was to eliminate the laser like corona produced by the KD aspheric kit. (And also allow the torch to headstand in my cabinet.) It's a 2.5" PVC coupler with a slice of 2.5" PVC in it and bound to the Mag bezel with electrical tape. I was too cheap to spend $50 on a custom bezel. I call it my redneck aspheric bezel.

  14. #14
    Flashaholic* Techjunkie's Avatar
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    Default Re: SST-90 Mag 2D build in progress

    I just replaced the beamshot post with a revised post with better beamshots. I decreased the shutter speed for the outdoor night shots, but I also used a lower ISO setting of 200 to match the indoor shots, so the longer shutter lag only brightened things up a litte. I should have gone for longer exposure still, or higher ISO.

    More imporantly (to me) is that the fixed white balance setting of "Sunlight ~5200K" really does an awesome job of differentiating the emitter tints. You can even tell the difference between the 4B MCE tint of #5 versus the rosier 4A MCE tint of #3.

  15. #15
    *Flashaholic* wquiles's Avatar
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    Default Re: SST-90 Mag 2D build in progress (better beamshots)

    Nice job with the beamshots
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  16. #16
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    Default Re: SST-90 Mag 2D build in progress

    Quote Originally Posted by Techjunkie View Post
    I just replaced the beamshot post with a revised post with better beamshots. I decreased the shutter speed for the outdoor night shots, but I also used a lower ISO setting of 200 to match the indoor shots, so the longer shutter lag only brightened things up a litte. I should have gone for longer exposure still, or higher ISO.
    Hey what brand and model of camera are you using to take your pics?

  17. #17
    Flashaholic* Techjunkie's Avatar
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    Default Re: SST-90 Mag 2D build in progress

    Quote Originally Posted by Fulgeo View Post
    Hey what brand and model of camera are you using to take your pics?
    It's a digital SLR, a Canon Digital Rebel XTi.

  18. #18
    Flashaholic* Techjunkie's Avatar
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    Default Re: SST-90 Mag 2D build in progress (better beamshots)

    I realize that the distance shots dull down the appearance of the beamshots. I purpously didn't zoom in to perserve the perspective of the distance, but I wish I had used a higher ISO. The fact that the tree has no foliage really hurt. Lessons learned.

    Here's an animated .gif showing the difference between the three throwers. First the recoil XRE Q5, then the KD Aspheric Q5 kit and then finally the SST-90 aspheric. I think it tells a better story than the pics do by themselves:



    Also...

    I'd performed most of the resistance reduction rituals on my direct drive torches in the past, but for a long time, felt like that's all they were, just rituals. Reducing resistance by milliohms seemed like a fanatic's obsession even to me. That was until I saw what a huge difference that shorting the tailspring of my carrier with copper braid made. I began to consider the drastic effect of every milliohm of resistance on a device that draws 9 Amps at only 3.6 Volts input, and how much voltage drop is caused by the slightest resistance at that current.

    Tonight I bit the bullet and bought the Deoxit/DeoxitGold kit from RadioShack for $15 and,
    now I am a believer!
    On half spent batteries, this torch was only pulling 4A at the tail. After using Doxit and Deoxit Gold on the internals (and externals) of the Mag switch all contact points on the carrier the Mag tailcap, end of tube and even the battery contacts themselves, the same batteries without additional charging measured a 6A draw.

    I repeated this excercize on my Lil' Giant and the result was identical. This deoxit stuff is a fortune, but for a high current, low voltage direct draw application, it's worth every penny. I might just try some of this stuff on the only hotwire I have that doesn't require conditioning the batteries to avoid popping the bulb.
    Last edited by Techjunkie; 01-11-2010 at 10:29 PM.

  19. #19
    *Flashaholic* toby_pra's Avatar
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    Default Re: SST-90 Mag 2D build in progress (better beamshots)

    Very awesome beamshots!

  20. #20

    Default Re: SST-90 Mag 2D build in progress (better beamshots)

    Very cool animated gif shot. Thanks!

  21. #21

    Default Re: SST-90 Mag 2D build in progress (better beamshots)

    Quote Originally Posted by Techjunkie View Post
    Tonight I bit the bullet and bought the Deoxit/DeoxitGold kit from RadioShack for $15 and,
    now I am a believer!
    On half spent batteries, this torch was only pulling 4A at the tail. After using Doxit and Deoxit Gold on the internals (and externals) of the Mag switch all contact points on the carrier the Mag tailcap, end of tube and even the battery contacts themselves, the same batteries without additional charging measured a 6A draw.




    This deoxit stuff is a fortune,.
    1.4A-6A with a couple squirts? AMAZING!

    2. sais the guy that drops $50 into a single led.
    If and when the the big dookie hits the fan, and global chaos ensues, i want a couple of quality AA lights within reach.

  22. #22
    Flashaholic* Techjunkie's Avatar
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    Default Re: SST-90 Mag 2D build in progress (better beamshots)

    Quote Originally Posted by waddup View Post
    1.4A-6A with a couple squirts? AMAZING!

    2. sais the guy that drops $50 into a single led.
    As the emitter heats up, Vf drops and current draw increases. I just measured 8.48A draw on a freshly charged pack (post deoxit).

    2. I'm penny-wise, pound foolish that way. Some stuff you just can't do without or economize on. The emitter falls into that category. Besides, I rationalized it this way: It takes 3 MCE to generate as many lumens and three of those in one torch = floody. I've been there and done that.

    On the other hand, I also discovered a $1 bulb that cranks out just as many lumens as this $50 LED, and it's easier to drive and focus.

  23. #23

    Default Re: SST-90 Mag 2D build in progress (better beamshots)

    i spent $15 on some deoxit about 2 years ago, ANYTHING electrical that is quirky is improved with a squirt

    ime.
    If and when the the big dookie hits the fan, and global chaos ensues, i want a couple of quality AA lights within reach.

  24. #24
    Flashaholic* Techjunkie's Avatar
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    Default Re: SST-90 Mag 2D build in progress (better beamshots)

    I removed the spring+braid from my "carrier" and cut down a KD "Mag shorty golden tailspring" that I had in my pile-o-parts to recess it within the tailcap.

    Holding the spring in place while mearuing with my DMM, I measured an 8A draw from the 2p26650 carrier through this new spring. That's a very small improvement in current at best, but I think the added force of using this spring instead of the old one with braid has improved the connection when the flashlight is fully assembled. (The other spring was weaker.) It seems a small bit brighter to my eyes this way and the installation looks cleaner.

    I'm also noticing more heat from the neck, but that might also be because I wrapped the neck threads with teflon tape to make it harder to defocus the lens. The tape might be thermally insulating the neck from the head. I think I'll change that tape to aluminum foil to avoid thermal insulation at the threads.

    Using the same "golden spring" I measured 10.5A draw from four AccuPower Evolution LSD NiMH C cells that each measured 1.26v open. I briefly considered changing the host to a Mag 3D and using this combination of cells and a resistor to get curent draw down to 9A. Runtime would increase a little, but I don't care for the added length or weight.

    This got me thinking once again about direct driving this emitter from a 4s2p AA pack. I might just bore out another 2D host I have laying around to experiment with a little more. I might not need a driver for this torch after all.

  25. #25
    Flashaholic* Techjunkie's Avatar
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    Default Re: SST-90 Mag 2D build in progress - Updated

    After reading of someone else's near perfect 9A draw from a FM 4s carrier in a Mag 1.5D and 4 German generic NiMH cells, I finally got around to experimenting with that 4s2p config of AAs that I mentioned on day one.

    Long story short - it's a no-go for me. It can be done, but there's a delicate balance between carrier resistance and brand of cells. I built my carrier into the torch for minimal resistance and I used white topped Duraloops. The result was an instant-blue of the emitter. After adding some resistance by introducing the Mag tailspring as a conductor, I was able to keep the emitter from instantly turning blue to slowly turning blue. I measured current rising from 12A to 14A as the emitter changed tint.

    I could have played with resistors and different cells, but in the end this grand experiment taught me a few things that made me decide to reassemble the torch as I originally had it with 2p26650.

    1. The DMM itself adds enough resistance to drop current significantly at this amperage. As proof I offer that once the emitter had been heated up from the over driving, the emitter would still slowly turn blue using batteries measuring 4.1V open only when not using the DMM to measure current. Using the DMM, I'd measure 8.5A and no color shift would occur. This leads me to believe that without the DMM, I'm delivering 9+ A to the emitter on 4.1V open when the emitter is this hot (and Vf drops).

    2. Nine amps is perhaps too much for this method of emitter mounting and cooling to run constantly. Possibly, I have too much Arctic Silver Thermal Adhesive between the emitter pad and the heatsink, but I don't think that's the case as the torch is getting pretty damn hot at these currents, which indicates that there is good thermal transfer from emitter to heatsink. Perhaps a surface mount solder to an MCPCB and a good silver thermal compound (not adhesive) between that and a heatsink slab to which the MCPCB is mounted with screws would be better. I know some would argue that's two thermal junctions from emitter to heatsink instead of one, but I argue that thermal adhesive is not nearly as good a conductor of heat as is the combination of separate junctions of solder and silver thermal compound.

    Enough blah, blah, blah, here's the pretty pics. Notice the tint shift at the higher current on the indoor shot. Also, unfortunately, the ambient light changed between the 8A shot and the 12.5A shot several hours apart, so the sky does not look the same, but I assure you, camera settings were the same. (Click thumbnails for larger pics.):


















  26. #26

    Default Re: SST-90 Mag 2D build in progress (better beamshots)

    Quote Originally Posted by Techjunkie View Post

    On the other hand, I also discovered a $1 bulb that cranks out just as many lumens as this $50 LED, and it's easier to drive and focus.

    Do tell?!

  27. #27
    Flashaholic* Techjunkie's Avatar
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    Default Re: SST-90 Mag 2D build in progress (better beamshots)

    Quote Originally Posted by Codiak View Post
    Do tell?!
    Here you go.

  28. #28
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    Default Re: SST-90 white wall hunting

    I played with a new reflector tonight, the 53mm wide by 30mm deep XRE reflector from DX. I ground off the threads and opened the hole to 16mm. By pure coincidence the perfect focal point is exactly the same as the aspheric that I'm using. That's pretty nice, considering the other reflectors I've tried required the Brightlumens heatsink to be raised a few mm and even have a beveled edge cut to allow the reflector to drop inside it a bit. Also, that P7 reflector cast a yellowish beam, this XRE reflector looks surprisingly white. I had to compare to a cool white emitter to make sure I wasn't overdrivng the 4500K SST-90.

    Below, I've compared that reflector to the DX P7 reflector which received the same treatment, the aspheric, and two MCE's in DX 53mm reflector with brass pill combos. All beamshots taken at ISO 200, 0.4 sec, WB=5200K. First shot at F4, second at F22. (clickable thumbnails for bigger shots):

    New 30mm deep XRE___same focal point as asph.__old DX P7 MOP


    Cool white MC-E in WF502B w/WF500 head, KD 3A driver


    Neut. Wht. MCE 2p+2p w/ 2x DX 20330 Mag 2C


    Cool white MCE F4______F22


    NW MCE F4____________F22


    4500K SST-90:

    30mm XRE MOP F4______F22


    Aspheric F4____________F22


    DX P7 MOP F4_________F22



    Reflectors compared:



  29. #29
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    Default Re: SST-90 Mag 2D build in progress - Updated

    OK, I'm officially obsessed with this one torch. I realize at this point that I'm basically blogging here... hopefully the stuff I'm learning will be of use to someone else.

    I had company over tonight (for my birthday) and I wanted to show off this new masterpiece. Before the guests arrived, I tested battery voltage, saw that the cells were only 3.85V at rest and popped them in the charger. Several hours later, hot off the charger at 4.15V at rest, I loaded them and handed the torch to my brother-in-law to take for a spin.

    59 seconds later I was yelling, "turn it off", racing toward him to do it myself. The SST-90 was turning blue.

    A quick test with the in-line DMM returned a near 10A current draw, but no blue. I switched to the clamp meter and one of the test leads and measured a 12.5A draw slight tint shift. I screwed the tail cap back on and instant blue. This is nuts.

    Out go the 2P26650, into an incan torch and used down to 4.0V open. Same results as above - test lead held in place and 12A+ draw. Cap on, instant blue.

    In go 3 somewhat used AccuPower Evolution LSD NiMH C cells. Remember these from before? They still haven't been charged, but now when I attach the lead at the tail and measure with the clamp meter, current draw starts up at ~6A and scales up over 10 seconds or so to 8A. Based on the observation with the tailcap vs. the DMM lead, I'm guessing that with the tailcap in place, the emitter is pulling almost 9A from the 3 NiMH C cells.

    So what happened? Do giant LEDs like this one need some burn-in time like overclocked CPUs do? Did the Vf of this emitter drop since it was installed after burning-in? Or, Is this just the Arctic epoxy failing to move heat away fast enough and thermal runaway is lowering the Vf drastically?

    Changing the way the emitter is mounted is not an option as it would surely be destroyed.

    As I see it, my options for this particular torch are:
    1) only run it in short bursts on the Li cells (not loving that one)
    2) add some resistance between the batteries and the switch or the switch and the emitter (maybe just changing the spring would be enough)
    3) just use the NiMH C cells (once it's hot it's at or near enough to 9A)
    4) bet on sector_cleared's 9A CC driver to lower Vout as Vf drops from heat production and get one of those.

    I was kind of hoping to avoid the driver and just go with a direct drive solution.

    This emitter is a tricky sucker. I thought I had it licked but it keeps throwing curves at me.
    Last edited by Techjunkie; 01-19-2010 at 10:25 PM.

  30. #30
    Flashaholic* ma_sha1's Avatar
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    Default Re: SST-90 Mag 2D build in progress - Updated

    "So what happened? Do giant LEDs like this one need some burn-in time like overclocked CPUs do? Did the Vf of this emitter drop since it was installed after burning-in? Or, Is this just the Arctic epoxy failing to move heat away fast enough and thermal runaway is lowering the Vf drastically?"

    Interesting finding,

    Since vf drops with increasing temp, perhaps you "cooked it" enough that made a perminant drop of vf?

    Can I send you my SSR for cooking? as my uncooked SSR seemed to have too high vf to be driven to spec with single Li-ion or even IMR 26650

    Too bad they don't sell SSR by vf bin like the P7.
    I took a P7 I bin vf & drove it with 1x IMR 26650 DD & It looked brighter than SSR-50 DD with 1x26650. So, my SSR vf. got be be higher than the
    I bin P7 (3.5v to 3.7v) or maybe even J Bin P7. >3.7v.
    Last edited by ma_sha1; 01-20-2010 at 01:58 PM.
    My Mods.. http://www.candlepowerforums.com/vb/...5&postcount=78
    Hobby only, I don't do custom mods as a service, thanks for understanding.

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