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Thread: Replacement of carbide lamps by LED lamps

  1. #31
    Flashaholic* 2xTrinity's Avatar
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    Default Re: Replacement of carbide lamps by LED lamps

    Quote Originally Posted by uk_caver View Post
    I guess it depends what you mean by 'improve'.

    White LEDs can seem cold, but yellower ones aren't necessarily much better. In the days when I made luxeon-powered lights, and the LEDs I got weren't sold by colour bin, about half were 'proper' white, 30% yellowish, with the rest a little blue (apart from a couple with a purple tint).
    Going straight from using carbide, the yellowish ones maybe seemed a bit less cold than the white ones, but didn't seem quite as good for actually lighting things up, or for colour accuracy.
    I think the old luxeons that were essentially cold white LEDs that ended up being "yellowish" by chance were not the same as current-generation warm white Cree LEDs, which appear closer to blackbody and less "greenish" than bin outliers that just happen to be warmer.

    Equally, though there can be initial comments when switching to a 'colder' light, that does seem largely to be a matter of adjustment.
    I believe different color temps suit different applications. For example, or trying to do intensive shop/design work, I like 5000k. For "ambient" light, I like 3000k. In most other cases, I prefer a compromise of ~3500k. I generally don't like to stray outside the range of 3000k-5000k.


    Commercially, tint doesn't seem to be much of a selling point, and I'd guess that minor complaints would generally be about something being too off-white in any direction (blue, yellow, red, or green).
    I believe a lot of the earlier "warm white" LEDs were essentially off-white toward yellow-green, as they still had too little red. Modern warm emitters, like the Cree Q2 linked earlier, are reputed to be muhc stronger in red -- so that it appears white -- but still not as good as a halogen in that respect.

    Also, 'improving' a wide beam is still a matter of taste. Though I'm happy with what I do regarding narrowing a wide beam somewhat, there are certainly people around here who really want a complete 180 degree spread.
    If you want a 180% spread, do your buddies a favor and use a diffuser over the LEDs -- this will help with glare immensely. You can buy lenses from Flashlightlens.com with diffusion film and AR-coatings already installed. I'd recommend a shallow reflector, with a diffuser. This will produce a flood light that still has slightyly more intensity in the center of the field of vision (similar to what you'd probably get with a "clean" carbide lamp).

    As for colour rendering - whatever the apparent colour temperature, 'white' leds have very little green and almost no red in their spectrum, so colour rendering is poor compared with a well-driven halogen lamp.
    From LED Museum, Spectrum of Cool White Cree LED:


    LEDs have no deficiency in green -- most current-generation actually emit the majority of their radiant output in the yellow/green region of the spectrum. The problem is same as old single-phosphor fluorescent used to have -- the "red" output is actually more like orange, which does make the overall packaging look white, but provides littel contrast when distinguishing say shades of brown. The best engineering solution to that would be to actually use multiple phosphors with the LEDs, just like modern multi-phosphor fluorescents.

    Maybe for a wide beam, a red or amber LED could be added to the mix to give a more carbide-like light, but I'm not sure many people I know would go for that if it meant extra power consumption/loss of efficiency. It'd also be trickier to match in a focussed beam.
    There isn't much advantage to adding amber -- the only real deficiency is deep red wavelengths. Adding a true red (rather than amber or red-orange) to an array of white LEDs, particuarly ones with a "greenish" off-white tint does produce some very good results. Efficiency loss is neglibile, a surprisingly small amount of red is needed to "fill in the gaps" in the spectrum nicely. I believe some of the warm white LEDs in the past have included multiple phosphors to achieve the same effect, and i expect more to in the future as LEDs are pushed for general lighting.

  2. #32
    Flashaholic* uk_caver's Avatar
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    Default Re: Replacement of carbide lamps by LED lamps

    Quote Originally Posted by 2xTrinity View Post
    I think the old luxeons that were essentially cold white LEDs that ended up being "yellowish" by chance were not the same as current-generation warm white Cree LEDs, which appear closer to blackbody and less "greenish" than bin outliers that just happen to be warmer.
    I'm sure the colour was more accidental, though of all the Lux Is/IIIs I used, I don't recall any looking noticeably green.
    A friend's commercial LuxIII-powered light does have a definite green cast, and though I guess the eye would adapt to it, when there are cleaner white lamps around, it does look rather nasty.

    Quote Originally Posted by 2xTrinity View Post
    There isn't much advantage to adding amber -- the only real deficiency is deep red wavelengths. Adding a true red (rather than amber or red-orange) to an array of white LEDs, particuarly ones with a "greenish" off-white tint does produce some very good results. Efficiency loss is neglibile, a surprisingly small amount of red is needed to "fill in the gaps" in the spectrum.
    Amber might give the carbide feel some people have fond memories of. I'm not sure how many people with carbide nostalgia are really too concerned about colour rendition.
    Quote Originally Posted by 2xTrinity View Post
    The problem though is with color mixing/packaging. An actual Emitter package that included a red die INSIDE the package would be pretty interesting, but probably not worth the trouble compared to a second phosphor.
    I guess a twin die brings up the problem of sharing power in proportion (or having twin drivers), whereas an extra-phosphor approach does balancing automatically. Maybe when use for indoor lighting takes off, multiphosphor white LEDS would find a ready market.
    Still, for a personal experimental light, reddening a wide beam with an extra LED is certainly possible, given enough space in the headset.

  3. #33

    Default Re: Replacement of carbide lamps by LED lamps

    Hi Tobias, I'm quite surprised that no one has mentioned the Stenlight S7 in this thread (http://www.stenlight.com/) -- it's a purpose-built caving lamp that is rapidly growing in popularity among USA cavers. I don't own one but many of my caving friends do, and it's really an impressive piece of work in terms of construction, light output, and efficiency. It's not cheap -- a basic setup of light + custom Lithium-Ion battery sells for about US$300 or so -- but all the cavers I know who have them have been extraordinarily pleased with them.

    There are discussions about it both on this board and at cavechat.org (the US NSS discussion board), eg

    http://www.forums.caves.org/viewtopi...06387cb3516203

    If you are looking for a caving-specific LED headlamp, I'd highly recommend you check out the Stenlight if possible. (I'm assuming it's available in Europe...)

  4. #34
    Flashaholic* uk_caver's Avatar
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    Default Re: Replacement of carbide lamps by LED lamps

    Doesn't the Stenlight run both LEDs in series?
    If so, it's not great for people looking for a smooth (non-spot) beam unless they lose the optics on both LEDs and then get another light for spot use.

  5. #35
    Flashaholic Tobias Bossert's Avatar
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    Default Re: Replacement of carbide lamps by LED lamps

    Quote Originally Posted by Beaker View Post
    If you are looking for a caving-specific LED headlamp, I'd highly recommend you check out the Stenlight if possible. (I'm assuming it's available in Europe...)
    Yes, I read the thread upon Stenlight headlamp and I looked at the page of the manufacturer. It seams to be a good and robust headlamp indeed. But it still doesn't comply with our requirements as I posted in the beginning of my thread.
    There are two LEDs in series, always used together. Each using its own optics. Consequently the only possibility to change the spacial pattern under use would be to attach and remove an additional diffuser, not very handsome in caves...
    The beam is a compromice between throw and flood: It neither meets one of both requrements. We need flood working light all over the day and for short term usage only super narrow beam (without spill).
    On the other hand it provides 70 lumens output for 3 to 5 hours only (consuming 4 to 5W, not quite good nowadays). So you will need 2 or 3 battery packs (up to 6 pieces of 18650 cells) per day...

    There is indeed a much more suitable headlamp on the market, www.scurion.ch, but I would like to surpass it technically and nevertheless avoid its high price (about $ 500).

  6. #36
    Flashaholic* uk_caver's Avatar
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    Default Re: Replacement of carbide lamps by LED lamps

    Leaving aside the underground practicalities, how easy would it be to fully diffuse a spot beam without losing a deal of light in the process?
    Wouldn't a diffuser tend to cause backscatter?

  7. #37
    Flashaholic Tobias Bossert's Avatar
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    Default Re: Replacement of carbide lamps by LED lamps

    After some month of experimenting I come back to this treat. We tested all kinds of optics – now I can demonstrate some reasonable solutions.

    1) Normal light for walking and climbing

    Neither TIR with narrow, medium or wide beam nor plain LED satisfied our requirements. On the one hand all TIR are not wide enough for walking (you tent to stumble) but on the other hand, plain LED without any optics is to fade (you can’t see where to go).
    We tested many combinations of two simultaneous LED and find one combination satisfying us in real cave tests: Combination of a medium beam with FWHM of about 16° and a very wide beam with FWHM of about 80°.
    I realized this with XR-E Q5 using Carclo ripple medium (10210 & 10205) and with SSC P4 U using Carclo wide angle reflector (10170 & 10363). The axis of the medium optics is horizontal (when you stand upright) and the wide reflector is declined downwards 20 to 30°, as shown in Figure 1.


    This free mounting without case was for photo documentation only.

    It is not easy to demonstrate the feeling of the combined beam in a picture. I put the LEDs 50cm apart from a vertical white wall while the photo was taken from about 150cm from the wall – otherwise I would need a fisheye photo lens losing the orientation. The medium beam is horizontal and the pattern therefore is circular. The wide beam is declined downwards and therefore projects elliptical; it just reaches the area immediately in front of your feet. In reality you will not realize the sharp boundary of the beam, this is due to the photo taken from thee times the distance from the wall.



    Both LED were driven by different current levels. The XR-E Q5 for the medium beam needs about 30% of the current of SSC P4 U in the wide angle reflector to achieve the impression of the figure above. We plan to provide two levels: 40m + 130mA and 90 + 300mA, so we can hold this level for about 24 or 10h with 6 alkaline AA.

    2) Pause light

    We plan to use the above mentioned medium beam with a current level of about 20mA.

    3) Spot to explore deep pits or high shafts

    At the beginning I was sure we should use Gaggione Mobdar or Gaggione LL3 because so many users mentioned them positive. But these TIR are relatively big and provide a lot of side spill too. There exist completely different TIR (‘catadioptric reflector optics’ using total reflection on the front plain and being metalized on the backside, e.g. Carclo 10144) with extremely narrow beam, but these beams are too narrow for us (at the ground of a deep pit you will see one big stone only instead of the floor of the pit completely). We tested almost all TIR and reflectors from Kaidomain and Dealextreme and others and found nothing satisfactory.
    Cree XR-E has its own internal optics narrowing the beam a little bit, so it is possible to gather almost all of its flux with a thick aspheric collimator lens. We also tested almost all acrylic lenses we found. One very cheep lens with 23mm diameter was suitable and performs quite good. This lens is sold with different holders (DX 4614, DX 4628) which do not fit for XR-E. Therefore we cut the bottom of the holder away and inserted a Carclo holder for Cree (10205). With this combination you can adjust the lens. Both holders form something like a telescope.



    This device is much smaller than Mobdar or LL3 as you can see in the following picture.



    The combination of the two holders allows adjustin the beam. The beam is narrowest when the lens forms an image of the die on the wall:



    The rectangular shape of the die is about 40x40cm at a distance of 5m. As you approach the LED to the lens, the beam gets broader, round but weaker too; the left beam is about 150cm in diameter at 5m.



    I also compared the single lens with Mobdar. The beam of the lens is set to about 70cm at 5m (rounded but not jet round). The peak intensity of illumination in the center of the beam of Mobdar is about 70% of this, but it seams that the overall flux of the Mobdar is higher and the beam is much more “beautiful”. On the other hand the beam of the lens is “without” spill, that’s what we need.

    We plan to use the single aspheric lens with XR-E Q5 at about 1A. This is for short term use only. It works fine with 6 fresh alkaline AA, but when they got discharged they will limit the current rather than the regulator. With NiMH AA cells this is no matter.

    4) As much light as possible for big halls

    We tested the SSC P7 for this. We found no compact TIR (< 30mm). Since P7 has no internal lens the original beam is too wide to gather all flux with an aspheric collimator lens. Smooth reflectors throw donuts or beams with a dark cross in the center. So you must use orange peel reflectors. But – as I know now – orange is not orange. The roughness should be high enough with respect to the focal length. Most OP reflectors I found at Kaidomain and Dealextreme were not rough enough. Only two of the smaller types can be used with P7 avoiding severe donut effects:
    DX 5951 (similar to KD 3317) has diameter of 18mm only. The hole for the emitter must be opened to fit over the dome of P7 (9mm). This gives a relatively wide beam with only a week donut.
    DX 3257 has diameter of 26,5mm. You must cut the holder side so that surface on the backside of the hole for the emitter is plain. Additionally you must open the hole to fit over the dome of P7. This gives a medium beam with a week donut.
    If you don’t like this week donut, use a diffuser from L2Optics or Polymere. But this will cost at least 15% of the flux! If we could find a stronger orange peeled reflector, the donut should be avoidable without diffuser. I just ordered KD 5405 (23mm), KD 3318 (24mm) and KD 5151 (25mm) to try these too. For the moment I prefer the DX 3257. You can see the beam of modified DX 3257 with P7 in the picture below.



    We plan to drive this P7 with about 3A. This is for short term use only. It works fine with 6 NiMH AA cells, but with alkaline AA the current will be limited to their strength naturally.

    5) Put all together

    At the moment we plan to build a headlamp with 4 LEDs and optics as described above. This should get not to big for a caving helmet, as you can see on the following picture:



    But what is about the housing?
    No idea at the moment – I still hope that some manufacturer takes my ideas and starts its own development on that base.
    But at the moment, there is no such manufacturer. Therefore I have to continue...
    For this I assembled the circuitry for such a headlamp using cheep drivers from far east:



    Next I will construct a prototype and lend out to my caving friends to optimize it. This will consume some time...

    P.S.: Moderator please help!
    The links to my pictures work well, but I can't insert images. After saving changes, they were gone. Why? Please, can anyone tell me what I'm doing wrong:
    I push the button 'insert image' than the window for the URL appears with default 'http://'. When I overwrite it by the link and accept, than the text window shows an icon at the place of insertion. After 'save changes' no pictures appear but all icons are gone too...
    P.S.: Problem solved now:
    I used Firefox 2.0.0.16 with add-in Control de Scripts 1.03 and add-in AVG Save Search 8.0, which do not insert images correctly. With older versions of Firefox or with MS IE there is no such problem.

    Last edited by Tobias Bossert; 09-25-2008 at 11:26 PM. Reason: Insert images instead of links (MS-IE works, new Firefox not!)

  8. #38

    Default Re: Replacement of carbide lamps by LED lamps

    Tobias,

    I applaud your effort and thoroughness. As a fellow caver, I am always searching for the ultimate caving headlamp and will look forward to seeing what you end up with.

  9. #39
    Flashaholic* uk_caver's Avatar
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    Default Re: Replacement of carbide lamps by LED lamps

    A four-LED light? That does seem a fairly serious project.

    Might it not be easier as a general 2-led caving light, and a more 'specialist' room-lighting and shaft-spotting light?

    I imagine there might be some kind of market for a specialist light among the large numbers of people who already have some other kind of caving light that they're happy with (Duo LED, etc)
    Possibly a specialist light would be better as a handheld unit, since for shaft-examining (at least when looking upwards), a helmet mounted spot beam can literally be a pain in the neck.
    When I was playing with some P7s, the main use I found for a very bright flood beam was for photography, which is also a use where a lamp is more useful in the hand than on the helmet.

    Also for the P7 room-light, have you tried using a conical reflector? If you don't want any kind of beam, just a rather more forward-biased light than you get from a naked LED, it's definitely worth trying.

    With your FWHM of 80° using reflectors - looking at the datasheet, a naked Cree has a FWHM of only about 90°.
    How different is the reflectored Seoul to a naked Cree?
    Is it just a case of the Seoul+reflector eliminating 'wasted' extreme-wide light?

  10. #40
    Flashaholic Tobias Bossert's Avatar
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    Default Re: Replacement of carbide lamps by LED lamps

    Quote Originally Posted by uk_caver View Post
    A four-LED light? ...
    Might it not be easier as a general 2-led caving light, and a more 'specialist' room-lighting and shaft-spotting light? ...
    Possibly a specialist light would be better as a handheld unit, since for shaft-examining (at least when looking upwards), a helmet mounted spot beam can literally be a pain in the neck.
    Yes, uk_caver, I know this discussions. There are pros and cons. About 20 years ago I constructed my first handheld halogene thrower (10W 6V in the housing of flashlight for 'flat battery' 4,5 V with 6 NiCD AA). Works very well at that time. Good when standing at the floor of a high shaft in the ceiling, because there is no problem taking it out of your baggage ant it is good for your neck. But bad in case you are descending a rope into a pit. On my personal icon you can see me with carbide lamp plus halogene thrower on my helmet (constructed 1995).
    Since the additional space and weight of the LED optics are very small, I decided to integrate all three lamps (working light with 2 LED, thrower with 1 LED and flooder with 1 LED) into the headlamp.

    Quote Originally Posted by uk_caver View Post
    Also for the P7 room-light, have you tried using a conical reflector? If you don't want any kind of beam, just a rather more forward-biased light than you get from a naked LED, it's definitely worth trying.
    Yes, I tried P7 with conical smooth reflector Carclo 10170. The beam is not homogeneous. I will look for some orange peeled alumine to try it for my own. But at the moment I have no source for alumine sheet with high orange peeling.

    Quote Originally Posted by uk_caver View Post
    With your FWHM of 80° using reflectors - looking at the datasheet, a naked Cree has a FWHM of only about 90°.
    How different is the reflectored Seoul to a naked Cree? Is it just a case of the Seoul+reflector eliminating 'wasted' extreme-wide light?
    There are some differences.
    1) XR-E has its maximum on axis and decreases the intensity continuously apart from it; at about 45° off axis intensity is half maximum. If you combine this with a narrow beam 30° off axis, than you get two maxima in the vertical. SSC P4 with Carclo 10170/10363 gives an flat intensity over almost 80° and than drops fast. If you combine this with a narrow beam 30° off axis, than you get one maximum only in the vertical.
    2) XR-E has reasonable spill outside of its 90° beam. This may dazzle your friends when talking with them. With SSC P4 and reflector you just have to decline your head about 10 to 15° and the eyes of your friends are out of beam.

    But the problem of dazzling is still unsolved. I experimented wit diffusors of Cree (L2-Optics) and Polymere, but are not happy with it. Both work well to soften and broaden a narrow beam (reducing the overall flux about 15%). But used with a extremely wide beam, the losses ar much higher and increase with off axis angle. This could be solved only by spherical or domed diffusors, but I could not find such devices on the market.

    Regards Tobias

  11. #41
    Flashaholic* uk_caver's Avatar
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    Default Re: Replacement of carbide lamps by LED lamps

    I do see that the ideal close-up 'spot' beam is probably something like your 16° beam, since it will light up a reasonably wide area close to the caver, but I guess that does mean that it loses enough performance at long distances that you need an extra tight spot beam.

    I find that even with a tight reflectored spot with a very sharp fall-off outside the beam, mixing a dim-to-medium spot with centre-biased flood seems to make the spot beam subjectively rather wider at short-to-medium distances (alternatively, the spot beam 'pulls out' the flood beam and makes it seem throwier even outside the spot).
    I think it's down to objects outside the spot beam still being somewhat visible in the flood after the beam has passed over them - as long as they don't fall into relative blackness, they stay much better in the mind's attention.
    This seems to work best with a lower power spot than flood beam, since there isn't as great a contrast at the edge of the spot. Too bright a tight spot can actually makes a light less usable close-up.
    Last edited by uk_caver; 09-21-2008 at 10:23 AM.

  12. #42
    Flashaholic MiniLux's Avatar
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    Default Re: Replacement of carbide lamps by LED lamps

    Quote Originally Posted by Tobias Bossert View Post
    P.S.: Moderator please help!
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  13. #43
    Flashaholic Tobias Bossert's Avatar
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    Default Re: Replacement of carbide lamps by LED lamps

    Hi uk_caver,
    there are two beamshots to compare bare XR-E with SSC-P4 and Carclo 10170/10363



    and



    I have many holders and 5 reflectors 10170. 3 reflectors snap in easily having a very good flatness of the beam and being nearely circular. 1 needs little more force to snap in but still has an acceptable beam too. 1 needs strong force and shows a beam with some (weak) artefacts and a shape somewhat elliptical. This one is on the photo - worst case!

    The beams are quite different. The emitter was 50cm apart from the wall with axis rectangular to the wall. The photo was taken from about 150cm with wide angle.

    Regards Tobias
    Last edited by Tobias Bossert; 09-25-2008 at 11:11 PM. Reason: Insert images instead of links (MS-IE works, new Firefox not!)

  14. #44

    Default Re: Replacement of carbide lamps by LED lamps

    Quote Originally Posted by Tobias Bossert View Post
    This could be solved only by spherical or domed diffusors, but I could not find such devices on the market.
    Check this http://www.khatod.com/pdf/pljt20_xlamp.pdf

  15. #45

    Default Re: Replacement of carbide lamps by LED lamps

    Hi Tobias,

    Thanks for all the info, keep it up. I have been having a small play around but only to the extent of fitting leds into an existing mining light. I have been using a DX 1917 which I found easy to cave with and it did not seem to raise too many complaints from others in the party although I have been using elecrtic for a while so I am used to not looking directly at people. Liked the info on the modified drivers so might have to change.

  16. #46
    Flashaholic* degarb's Avatar
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    Default Re: Replacement of carbide lamps by LED lamps

    Great thread. Worth reading a second time.

    Daily, I do task work with headlamps. But found an essential missing puzzle piece is the wristlight. I've been building (left) wrist-lights since December. So far, best setup is an xr-c coleman 75 lumen two inch head hacksawed off, velcroed on to the power pack of 4 AA that is glued to elastic and velcro. I adjust to angle I need, as needed per task.

    The benefits of a wristlight over a headlamp alone are several: 1. when walking the wrist light is pointing and illuminating your feet, so peripheral vision can see stumbling issues. 2. you can flick a thrower about faster than you can whip your head about, to find things and spot danger. 3. more flood and field of vision than just head lamp. 4. law of inverse square means brighter walls gut level and below. 5. extra battery source. 6. backup if head lamp breaks. 7. much better textural relief vision, as a silloette shows shape of walls (I can spot baseboard dust from 25 foot.) 8. more diversity of light temperature and angle means more subtle understanding of what you are looking at 9. another 75 to 100 lumens at 1 watt, minus the obvious losses.

    I settled on the $20 xr-c coleman over the floodier 3 aa xr-e(hack saw off head for aa conversion) since throw is awesome with better than lux1 corona. I use rheostat, where the xrc throws great at 200 milliamps or as low as an efficient 80 milliamps , but rocks at 400 milliamps to astonishing effect.
    Some people are all lumens and no lux, while others are all lux and no lumens. Some just thank God they have neither.-- All of my lights have throw--some pretty darn far, into the garbage.

  17. #47

    Default Re: Replacement of carbide lamps by LED lamps

    Hello Tobias. This reflector for P7 might be interesting http://www.ledil.com/datasheets/DataSheet_Boom_p7.pdf

  18. #48
    Flashaholic* uk_caver's Avatar
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    Default Re: Replacement of carbide lamps by LED lamps

    The two wider-angle devices seem to have definite patches from the 4 dies in the LED, even though the narrower-angle one doesn't.

  19. #49
    Flashaholic gillestugan's Avatar
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    Default Re: Replacement of carbide lamps by LED lamps

    Great work Tobias!
    Thank you so much for showing how to wire multiple PT4105 in parallel using one switch for regulating output to all of them.

    My plan is to build a lamp for caving and general outdoor using two MC-Es. One very wide flood and one narrow.
    I'm probably going to use 4 X PT4105 and the dies wired 2 in series with each pair individually driven.
    This will give me a very wide input range of about 8-18V.

    Regarding the housing:
    I've used an aluminium box for a 3X XR-E setup which works very well. It handles the heat well, is waterproof (if o-ring or other seal is used) and is quite cheap. EUR 4.40. Just not as good looking as I wanted. I would prefer an oval housing. Anodised in gold, red or black. :P
    Here is the box: http://www.conrad.de/goto.php?artikel=522369

    Regards /Gille

  20. #50
    Flashaholic Tobias Bossert's Avatar
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    Default Re: Replacement of carbide lamps by LED lamps

    Long pause, but work was going on...
    Now I completed my first test device: It's on a four days trip into a 95km-cave (Hierlatzhöhle) at the moment to get real life experiences with it.
    My first test device is completely hand made - no usefull bases for professional manufacturing.
    The purpose is to demonstrate the feasibility of improved lightning with respect to commercial high end headlamps. The crew also uses some Scurions at the same expedition and one Stenlight.
    The test device is build in a plastic case (ABS), the original lid is changed by a 3mm alumine back plate. The outside dimensions are width 85mm (plus switch knob), hight 56mm and depth 22mm (plus outstanding lower lens tube). The weight is 155g without mechanical helmet fixation and without cable, battery case and connector. With 1m cable (as used now to carry the battery in the chest pocket) and connector the weight of the headset is 195g.




    The switch has 6 positions:
    1. off
    2. pause light (upper source in picture: XR-E Q5 WC & Carclo 20mm frosted narrow)
    3. worklight low (= pause light + lower source in picture: XR-E Q5 WC & Carclo 20mm wide angle reflector & self edged glas lens; declined)
    4. work light high (= work light low but higher currents)
    5. shaftspot (left source in picture: XR-E Q5 WC & EdmundOptics lens AX77183)
    6. hallflooter (right source in picture: P7 CSXO & modified DX 3257 & Ledil Cree 26mm diffuser 20° bond with epoxy onto a glas lens)
    With 6 AA NiMH (2500 mAh) the runtimes are: 2. more than 250h, 3. about 25h, 4. about 8h. Positions 5. and 6. are for short term use only (drawing about 4w / 12W).

    With respect to my former posts, some modifications took place:
    I didn't found a reasonable small OP reflector for P7 not throwing a donut, therefore I use now a moderate diffuser. This would be even strong enough to use a SMO reflector (DX 5955) . The diffuser is acrylic - not usefull without a separate hardened cover. When I put a plane glas lens in front of it, the light passes 4 surfaces giving reflections. Therefore I bont the diffuser with its plane side to the glas lens using a clear epoxy. This improves the transmittance noticeably. As a side benefit it stabilizes the glas lens: if it breakes up, there is a crack, but the acrylic part still holds.
    I got a big collection of lenses and reflectors at home now. The outstandingly best glas lens is AX77183 from EdmundOptics (AnchorOptics), which allows a very compact thrower. The lens has a usfull diameter of 19mm. The internal depth of my case (19mm) is sufficient for XR-E on a star board to throw a sharp image of the die to a wall. I mounted the lens by about 1mm nearer to the LED (with respect to the inner side of the housing) to smooth out the details of the die image. The picture shows the beam 2m apart from the case; FWHM is about 4,3°.


    The worklight gives a combined pattern. The upper source is a 20mm Carclo TIR, the centre is horizontal. The lower source is a 20mm Carclo wide angle reflector, originally designed for lambartian LED only. Slightly modified to XR-E the FWHM is about 65° only. I covered it by a glas lens, which I edged by myself. There are two beamshots of the worklight. The distance of the headlamp from the wall was 50cm, the center of the upper part is slightly higher than the middle of the folding rule (at 100cm).



    The four days cave trip ends December 30. If there is no defect, the test device will be used on the next four days cave trip on January 3.

    I will post the findings!
    And naturally discuss the experiences an try to improve the device.

  21. #51
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    Default Re: Replacement of carbide lamps by LED lamps

    Wow! What a project. It's probably too late to mention this, but CR123A Primary batteries would be much better suited to caving than alkalines. They have a much higher energy density, are more reliable and work in more extreme temperatures than alkaline batteries. I'd say the weight you could save would definitely be worth the effort. If you are having a hard time finding them, order them in bulk online for pretty cheap. For such a hobby that's so demanding on lights, I would not trust alkaline batteries,

  22. #52
    Flashaholic gillestugan's Avatar
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    Default Re: Replacement of carbide lamps by LED lamps

    Looks good. but a few more scratches i the plastic please would look good That is some serious testing grounds. Wish we had caves like that here in Sweden.

    Guy's dropper: He wrote he used NiMHs not alkalines. And thy are more reliable and practical to use in such environments than Li-Ion. Using Li-ions you must use a hardcase to protect them from mecanical damage that comes from crawling, climging and sqeezing yourself through narrow passages. And a fire in your pocket is the last thing you want when you are in a position where you are unable to reach it.

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    Default Re: Replacement of carbide lamps by LED lamps

    Ok, good. NiMH is a good economical battery type for that application. I should mention, however, that Li-ions are very easy to store safely. If I am carrying them on my person, I store them in either Tube Vaults or Airborne containers. They are the most waterproof and impactproof containers, as far as I can tell.

  24. #54
    Flashaholic Tobias Bossert's Avatar
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    Default Re: Replacement of carbide lamps by LED lamps

    Quote Originally Posted by gillestugan View Post
    Thank you so much for showing how to wire multiple PT4105 in parallel using one switch for regulating output to all of them.
    No, Gille, please look to my circuit diagram carefully!
    It is easy to parallel driver boards with C300 or C310, since LED+ is identical with Power+
    As far as I understand, it is not possible to parallel those boards with PT4105 easily, because the LED is floating, LED+ and LED- both are not fixed.

    My plan is to build a lamp for caving and general outdoor using two MC-Es. One very wide flood and one narrow.
    I'm probably going to use 4 X PT4105 and the dies wired 2 in series with each pair individually driven.
    This will give me a very wide input range of about 8-18V.
    One benefit of MC-E above P7 is that each die can be driven separately. Your application with two MC-E does not need any paralleling of driver boards since you plan anyhow to build four paths each with two dies in series: each one can be driven with its own PT4105.
    The efficiency of most boards decresases, when the difference between input voltage and output voltage increases. Therefore it makes no sense to drive two parallel pathes of two serial dies (Vf~7V) with two separate drivers at 18V. It would be more efficient to use only one driver for all of them in series.
    Please remember, that switching just single dies off will propably decrease the "beauty" of your beams pattern. The advantage of boards with PT4105 is that they can be dimmed to quite low levels without loss of efficiency. Therefore it is better to dimm all four dies istead of switching then one after the other off. Also the output of all four dies each dimmed to 1/4 of current is higher than of only on die remaining on full current.

    Regarding the housing:
    I've used an aluminium box for a 3X XR-E setup which works very well. It handles the heat well, is waterproof (if o-ring or other seal is used) and is quite cheap. EUR 4.40. Just not as good looking as I wanted. I would prefer an oval housing. Anodised in gold, red or black. :P
    Here is the box: http://www.conrad.de/goto.php?artikel=522369
    Regards /Gille
    Thanks for this link. This cases are very stable, my be I will take it for the next test device to improve mechanical stability. But first I'm waiting for the experiences with the first test device in real life situation of cave expedition...
    Regards Tobias

  25. #55
    Flashaholic gillestugan's Avatar
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    Default Re: Replacement of carbide lamps by LED lamps

    Thanks for your input.
    And yes, all dies in each led will always see roughly the same current to keep the beam uniform.

    I planning on using 11.1V battery packs, which is closer to output voltage of two cells. (I already have 11.1V packs from another headlamp.)

    Will use a 2 pole 5 ways rotary switch similar to yours, but I have decided to wire it off-on-on-on-on for both leds, using a mosfet to keep current in the switch low.
    I will then use the other pole for selecting levels, using resitors for controlling the "off" and "on" for the leds in the different modes, where "off" will be a led driven at less than 1mA.
    The resistors are wired with diodes in series as in your chart. Thanks, I would probably have gone looking for a bulky 5(6) pole switch if I hadn't seen your chart.


    I've also been doing some testing with PTCs for temperature regulations. Replacing the resistor with value 1k8 in your chart with the thermistor.
    I haven't decided yet if I want it or not. With it I wouldn't have to worry about cooling, but Im not sure I happy with the indefinite levels I would get. The air temperatures in a cave are stable, but I use headlamps outdoors as well, an it's a big difference between -20 and +25 degrees celcius. Maybe if I find a PTC whith a sharper knee...

    I have run into one mayor problem. You know it too well - the optics.
    The MC-Es are really not easy to work with. Most optics gives a beem with FWHM of 18-40 degrees. I want one less than 10 degrees and one more than 60 degrees. Haven't found any of them.
    The only narrow ones are 35mm wide and then there is no point in using a MC-E as a 4*XR-E 35mm Ledil cute lens is smaller, more narrow and makes heat sinking easier.
    Im interested of 20mm optics, maybe 25mm as I want to keep the housing pocket sized.

    Have also been looking at the tiny XP-E leds. Khatod has a 25mm 4*XP-E lens 10 degrees FWHM. Looks good for spot, but I havent been able to buy and try it yet (or seen someone elses beamshots).
    The XP-Es as well as the MC-Es are not uniform in colour when used without optics. They are very blue in the middle and very yellow-green further out. (i have only tested the WG tint.) Was hoping to be able to use them for flood without a lens, but the XR-Es are much better.
    If you are interested you can find a lot of beam shots of various lenses and reflectors in this thread at MTBR.

    So right now I'm trying to decide if I should build a MC-E light with one 15 and one 40 degree reflector with part available, or if I should wait and see if better optics will come for the XP-E.

    I haven't got a program to draw circuit schemes, but maybe I will try to find one. Did yours actually have the PT4105E in the component library?

    Regards
    /Gille

  26. #56
    Flashaholic* Barbarin's Avatar
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    Default Re: Replacement of carbide lamps by LED lamps



    While I’m working on a headlamp that would be good enough for caving and cave-diving, it won’t be 100% optimal for caving from the point of view described by Tobias and others. As long as he has been kind enough to give me his opinions in my thread I wanted to give you my suggestions here for the project that is being discussed.

    First of all I would like to link to a excellent post by Kiessling about the importance of flood lights and low levels.

    Clearly, when it comes to really long term use of artificial and self attached lighting, on close distances, a spot, even a well diffused one, can be fatiguing and to some point, that “through hole view” could be even harmful (always on a very long term use).

    Definitively a long term use caving headlamp designed for a comfortable use should have a pure flood light.
    I've been playing for a while with “zoomable” optics. The problem with those is that at least the ones I have been testing are "pure spot" beams in which you just have the option to choose the angle of the spot, but it is not a beam with a combined spot and corona.

    This picture explains it better.

    But, what if we use one zoom and one flood with independent switches and common output control? (Based on two XRE )

    We could have all the options described by Tobias:

    1) Normal light for walking and climbing

    FLOOD ON + ZOOM ON. Output and zoom adjusted to needs. (large room, small tube…) From 0,5 to 7 Watts.

    2) Pause light

    FLOOD ON ZOOM OFF. Output to minimum. Less than 0,1 Watts.

    3) Spot to explore deep pits or high shafts

    FLOOD OFF ZOOM ON. Output 100%, zoom adjusted to distance. 3,5 Watts.

    4) As much light as possible for big halls

    FLOOD ON ZOOM ON. Output to 100% Zoom adjusted to distance. 7 Watts.

    Now the challenge is how to design this to not need and screwdriver in your hands to adjust easily and fast the beam and output to what is needed each moment. By the now we know that we need three controls.

    1. Output selector.
    2. LED selector with three positions ZOOM-FLOOD-ZOOMFLOOD.
    3. ZOOM actuator.

    What do you think on this?








    Last edited by Barbarin; 12-30-2008 at 06:02 PM.

  27. #57
    Flashaholic* Barbarin's Avatar
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    Default Re: Replacement of carbide lamps by LED lamps

    Quote Originally Posted by Barbarin View Post



    ...This picture explains it better.

    Obviously I didn't linked any pictures. Here it is:



    From left up to right down you can see: 1-4, different degrees of ZOOM. As you can see with this kind of zoom you always have a spot, with near no spill. On picture 5 a pure flood CREE XR-E with no optics at all. Pic 6 is a reflectored single die LED, in which you can see clearly the effect SPOT+Corona.

    What I'm suggesting for a caving dedicated light, is the addition of any of the zooms + flood, working together but when on resting time or in "search" (just spot).

    Javier
    Last edited by Barbarin; 12-31-2008 at 02:37 AM. Reason: typo

  28. #58
    Flashaholic Tobias Bossert's Avatar
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    Default Re: Replacement of carbide lamps by LED lamps

    Thank you, Barbarin,
    your proposal seems to be a good compromise between number of required independent LEDs and mechanic/optical complexity. I think this is much more flexible approach for cavelight than your 1-LED proposal in your actal thread http://www.candlepowerforums.com/vb/...d.php?t=217415
    In some way this is an improved Scurion solution (also 2-LED). Scurion combines a bare emittor (P4, not XR-E) with another LED in a narrow beam TIR (Gaggione LL3).
    You replaced the TIR by a pure optic lens which gives the posibility to vary the focus and which doesn't produce spill.
    As far as I can see, your new 2-LED solution covers all these light combinations I required a 4-LED solution in my test device: Congratulations!

    Unfortunately every benefit (only two optics, LEDs and drivers needed) requires some effort: Your 2-LED solution needs mutch more mechanics than my 4-LED solution.

    1) You need to provide a mechanic adjustment of the focus.
    When you switch from "work-light" (defocused beam) to "shaft-thrower" (focused), you will have to switch electrically and mechanically!

    2) You need to provide separate declination adjustment of beam and flood
    Fortunately no focus change is necessary between "work-light" and "huge-hall"; but in this case you need to readjust the declination of flood with respect to throw, otherwise you will illuminate the floor especially!

    I'm no mechanic expert, but as far as I can imagin, the 4-LED solution will get smaller and more lightweight than any adjustable 2-LED approach. And even easier to use too...
    But the adjustable 2-LED solution is more universal, because you can vary continuously. The fixed 4-LED solution is restricted to what it was preset.

    Tobias

  29. #59
    Flashaholic* Barbarin's Avatar
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    Default Re: Replacement of carbide lamps by LED lamps

    Hello Tobias,

    Good points.

    For a homemade light the mechanical complexity of this option proposed makes it less viable, but for a industrially developed and made product it could be the way to go if the design is clever and the use intuitive. Even one of the selectors could be removed if we use just a rotary switch with enough positions such as:

    1. OFF
    2. FLOOD 30 mA (Resting) 10 lm
    3. FLOOD 300 mA (Moving on small pasages ) 90 lm
    4. FLOOD+SPOT 300+300 mA (Regular use) 180 lm
    5. FLOOD+ SPOT 700+700 mA (Large rooms) 320 lm
    7. SPOT 1400 mA (Search mode) 300 lm

    With just one Li-ION 18650 2200 mA runtimes would be like 70 hours, 7 hours, 6 hours, 1,5 hours, 1,5 hours.

    Can this be done on a compact desing? To start with two LEDs housing should be smaller than a 4 led one, assuming same construction requirements regarding waterproofness (IP).. Uff, let me think about it during the next days...

    Regarding your point 2, I think if you choose the right angle and your flood is wide enough you mneed not adjustment on divergence, as long as you always need light in the floor near you, large or small rooms.

    The "Hellmeet light" is not so apropiated for caving as it has more a "raid under any condition" approach than a pure cavediving light.. but you won't get lost on a cave using it.

    I'm going to try some pictures.
    Last edited by Barbarin; 12-31-2008 at 04:56 AM.

  30. #60
    Flashaholic Tobias Bossert's Avatar
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    Default Re: Replacement of carbide lamps by LED lamps

    Quote Originally Posted by Barbarin View Post
    For a homemade light the mechanical complexity of this option proposed makes it less viable, but for a industrially developed and made product it could be the way to go if the design is clever and the use intuitive.
    You are completely right, homemade optimum and industrially produced optimum are different!

    Even one of the selectors could be removed if we use just a rotary switch with enough positions such as:
    1. OFF
    2. FLOOD 30 mA (Resting) 10 lm
    3. FLOOD 300 mA (Moving on small pasages ) 90 lm
    4. FLOOD+SPOT 300+300 mA (Regular use) 180 lm
    5. FLOOD+ SPOT 700+700 mA (Large rooms) 320 lm
    7. SPOT 1400 mA (Search mode) 300 lm
    It's only 6 positions, same as me too!
    The 90lm is very demanding. XR-E R2 is >114lm@350mA and you will lose some % of light internally too. Flood is o.k. but with the optic lens it would be rather 70...80lm.
    As far as I see, XR-E R2 at the present is availlable in color WG only, too greenish. WC or WD would be more nice, but these are Q5 only.

    With just one Li-ION 18650 2200 mA runtimes would be like 70 hours, 7 hours, 6 hours, 1,5 hours, 1,5 hours.
    70h, 7h, 3.5h, 1.5h, 1.5h

    Can this be done on a compact desing? ... Uff, let me think about it during the next days...
    I'm verry eager to see whether you can solve these demanding technical problems!

    There is another problem I'm still looking for a better solution:
    Surion has a bare P4 which glares very strongly. There will be no improvement with respect to glaring when using a XR-E.
    I tried to avoid glaring by a combination of LED, wideangle reflector and diffuser lens. It does the job verry well but at the expense of at least 30% light loss.
    The problem is, that all known diffusers work well as long as the light passes nearely orthogonally. With large incident angles the losses increase dramatically. For this task I would need domed glass front lens (18mm diameter, 4,5...5,5mm hight depending on glass thickness 1...2mm). If I would get those, I can edge or sand them at the concave side by myself. This would decrease the losses and improve the flood tremendously.

    Tobias

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