@ waltherK:
The measurements were made at 5 meters and 10 meters and 12 meters. All add up to about 55 kCd calculated back to 1 meter.
Did a measurement just now at 1 meter that shows about 37 kCd.
Took it outside to see if there was problems with focus. Seems to my eyes that the beam converges at about 90 meters (this is really hard to tell and could be a optical illusion my eyes pick up) after which it starts to disperse.
Hope I am using the correct terms here - please feel free to assist me if I am not. That spot does not move when moving the reflector in or out. It simply disappears.
@ Rufusbduck:
Will look into it later today when I get a new batt for my dmm.
I have used it earlier though with a XML where I confirmed it gave 3,8A.
However there is a chance that I ruined something with my soldering iron when installing it. Not totally unlikely.
There is also something else. Because I was suspecting that the current might be too much for the XR-E, I installed the driver with quite long wires to make it easier to dismantle and swap something out, be it driver or led. Maybe 12 cm total length. Too much power may be lost there.
Will investigate more when time permits.
My DMM gave up on me.
It cannot read amps anymore and it measures voltage too high.
I guess the moisture in the old stable finally got to it.
This will take some time to replace.
I think I’ll go the DD route until then…
I saw that thread when U posted it. But de doming an xml is too tricky for me. 5% success rate? Not for me.
Anyhow I had a xml in it and it performs fine ~ 79 kCd after 30 sec. 76 kCd after 3 minutes.
But I was hoping to do much better here because I think the spill of a xml light is too bright and gives too much back scattered light which means that I experience the light on target less bright and the contrast of the target area to be poor.
Just tried to cut the wires and direct drive it off the 1s2p battery pack i made.
That sucks! It is even dimmer than without the driver. I did not meter it because it is apparent merely by eye. I would say a 30 to 40 % drop in intensity.
I then dismantled the battery pack to check voltage/charge state. The voltage is 4,16 V at rest.
This leads me to conclude that my driver soldering is okay and that the led is seeing the correct 3.8 amps.
There is still the chance that the soldered joints on the led pads are not good.
Those will have to be reworked anyway when I center the led.
Without jumping to conclusions but just guessing I’d say that the reflector is too shallow for the narrow 90° light emission angle of the XR-E.
Maybe I am only utilizing the outer part of the reflector because the center part is “in the dark” so to speak. Just guessing here.
Because the measurements at 5, 10 and 12 meter all result in 55kcd, it proofs your measurements are good.
You should adjust the focus to be good for infinity, as that it is what you want to achieve with a thrower.
90meter is good enough, like you say, with (only) 55kcd at that distance your eyes cant make much more of it.
It proofs it is not showing the actual intensity, as its not like the 55kcd measured on different distances.
But what I meant, was that it would be interesting to see how much lux without the reflector is measured from the led.
No a must, but it gives data for comparisoon with other builds and projects.
I wonder if it could be improved with an aspheric lens. Also did you ever do the test on the xre bonded to copper showing current vs output? The series you ran on xml, mce, xpg, and xre I found quite illuminating.
@ Rufusbduck : I am sorry but I never did any of that. You must be thinking about MATCH. He has contributed so much funny, wild, mad and wonderful information to this forum.
You’re absolutely right, I was thinking of Match. He maxed the output of an xre at ~2100 mA but that was on a star, not direct to copper. This is the first documentation I have seen at such a high current and I confused the two threads.
Bah...I'm dumb. I read the initial post too fast and completely missed the fact that you directly mounted the emitter on copper. That's Awesome! Ledsmoke, congrats on being one of the few around here to attempt it! Btw, yes those little pads on the bottem of the emitter can be a pain to grind away :)
As for the output now....I'm not sure? I've been meaning to copper mount the xre-r2 that dthrckt sent me to test, but haven't done so yet. Still, with a direct drive at 2.2 amps I can't imagine the lumen output tipping over...so the lux should be there.
Hmm...let me get off my arse and copper mount that emitter of mine so I can hook it up to the test rig. Hopefully that'll provide some extra info.
Again, nice work on Ledsmoke on the copper mounting.
I totally understand the “stalled” bit. When inspiration fails, it sometimes helps to set it aside and let it percolate. One of my mods took over a year to complete! Soon though, that xre will demand your attention, and when it does we’ll be ready. 8)
Looks like OP burned the XRE by over driving to 3.8A, since Direct Drive at 2.2A would not bring up the lux.
There is such a things as too much of a good thing after all.
2.2A with direct to copper is perfect.
My Mag Dragon Jr. XRE 2.4 Amp with 66mm DX aspherical lens reached 231,500 lux at one meter
There is a thread on CPF for it, unfortunately, CPF is down
IIRC, past 2.5 A the XR-E starts to get dimmer, probably due to heat or something, so it is possible that if you drove the LED at a lower current, it would have given more throw. The XR-E might be burned out from the current. Also, the XR-E doesn’t throw as much light out the sides, so less percent of the light hits the reflector and gets focused.
A XP-C at ~1-1.2 A in that reflector might give the most throw. Small emitting area and a slightly over driven LED.