Just off the CNC - Update: It's Alve!

Yes, the optics can easily be switched even after the whole thing is fully assembled. Remove the front bezel and pop the optics right out.

To my knowledge, the only thing that will fit my emitter arrangement is the CUTE-3 Optics from LEDiL, so I'm stuck with those, but I could Use Wide, Medium and Narrow is different ratios.

PPtk

yeah, that should do the job :) I didn't even realise that you can't get Cute-3 elliptical optics, which kind of makes sense as you'd have to use the triple in a certain orientation for it to work, but it's still a bit of a shame because those wides are going to be putting a lot of their light up into the sky (and mediums and narrows to lesser and lesser extents). I'm more used to 20mm optics where there's a bit more variety.

that's a really neat bit of engineering. Varying current to different triples would be handy if you wanted to vary the beam within a certain thermal envelope too.

I don't doubt that you've done your modelling and the thermal paths look exceptional, I'm only wondering if the efficiency losses from running the LEDs at higher currents are worth it, when you could get a similar light output at a lower current and LED temperature. A guy called Troutie on the mtbr DIY light forum has done some tests of light output vs. temperature for the XM-L and it was pretty instructive, even if I can't find it any more :(

Both of my lights (~10W and ~20W, so a shadow of yours) have their thermal trip set at 60C, so that the LEDs should never run at more than 90C, although that is more to protect the driver. Their real world temperature is most likely a lot lower than that. I just think that a trip point set so high doesn't give you much of a margin, that's all.

I would be really happy if the CUTE-3 Optics were available in an elliptical, but sadly, they're not. Thankfully, although I'm going to be pointing a bit of the beam up into the sky and down into the dirt, I'm pretty confident that I have enough raw lumens that it just won't matter.

Not only does it help keeping thermals under control, but because I have the different optics, it also allows me to vary the beam pattern. I can turn on All flood, All Spot, or any combination that I want.

I have little doubt that you're quite right - Almost as many lumens will be produced at 2 amps as will be at 3 because of thermal sag. That's why the dimming function exists. Most of the time, I can run at 66% (2 Amps) which will be more than adequate for most situations - when I really need max power though - it's available. Unless my modeling is way off, the 100C trip point is still 20C shy of being destructive to the emitters. For me, that's plenty of margin. Keep in mind also that my thermal model suggests that 100C would be almost impossible to reach - 78C is max expected even under really extreme circumstances (90F Ambient with practically zero air-flow). 100C is the Safety Shut-off point, it has nothing to do with lumen efficiency. (edited - It's actually not a "Shut-Off" point, it's a back off point. The light will not go off, it will just self-dim to maintain < 100C)

PPtk

Dimming Code Finished. Small demo - The bluetooth communications routines are not done yet, so this isn't being 'controlled' by anything - the DSP is auto-looping from max bright to zero and back again. Right now, the current limit is set to 1.2Amps instead of the full 3 because I don't have any heat-sinking behind the circuit board.

PPtk

Already looks bright as heck in the video.

Foy

It is - It was really difficult to video without the video camera going into saturation. I had to turn all the lights in the room on, and you can still see how dark my desk-pad gets as the camera closes the aperture.

PPtk

I don't doubt that last bit at all :)

I think that's one of the coolest things I've heard of. If bike lights could be bigger, this is one of the things I'd hope to see.

you're right, I was somewhat mixing the two things (thermal sag and safety cut off) - one is about efficiency, which is somewhat moot if your alternator can handle it, and the other is about protecting the electronics, which you seem to have perfectly under control. Being able to control power levels is a huge boon and might even help with visibility in different conditions (dusty, foggy, highly reflective terrain) where less light could mean better sight. I almost always run my bar light at ~1.8A as there isn't a huge difference between that and 3A (although I'm told the difference is more marked the more LEDs you're running) and the difference in battery life is considerable, but it's nice to have that little extra when I need it or when I want to wind up my mate in front of me :)

Well, I've been really busy again - and I've not had much time to invest in this project.. But I did get some more XM-L's soldered down (4 sets of 3 installed now) and There are no interaction problems. The sets can run quite happily in conjunction with one another. The problem at this point is with taking measurements and looking at signals - it's just SOOO bright in and around the circuit board that I can't even see the components. I finally put some diffusion film that I had laying around over the groups of emitters, and that helps a lot.

Since the rise/fall times of the FET Gates was a problem, I figured you all might be interested in how well the new gate drivers work.

This is a capture of the scope taking measurements of (top) the gate of the fet and (bottom) the output of the DSP / Input of the Gate Driver. These parts work incredibly well.

As can be seen, there is 47.7 nano-seconds of delay from input at the gate-driver to when the gate driver begins driving the gate. Once that happens, these things slam the gate voltage from zero to 5.5V (well above Gate-Turn-On / rdsOn) in a frightening 6 nano-seconds. Incredible. 53.7 Nano-Seconds for the whole turn-on. The turn-off has roughly the same delay, and an even shorter fall of about 4 nano-seconds. Remember that a nano-second is 0.000000001 Seconds. We're talking FAST.

Going well, just slow because of my limited time.. But forward slowly is a hell of a lot better than backward quickly :)

PPtk

Where in Michigan are you from? I am originally from Michigan, lived there until I graduated from school and moved to NC for a job, I really miss Michigan though to be honest.

South East. The Northern Suburbs of Detroit.

I've tried to leave twice. Never works. Hard place to get out of your blood..

PPtk

Ah, I was from the West Coast. Spent 5 years up at Michigan Tech though before moving down here, like I said, I miss it.

Oh I also wear 2 or 3 layers of sunnies/dark tinted safety glasses to reduce the amount of light, really helps reduce the squint factor too

@PilotPTK what exactly did you use for seal? I've been searching for silicon sheets to cut out seals.

Not the Pilot-man, but search ebay for silicone baking sheet. Just make sure it's smooth both sides. (Some have texture on one or both sides.) I found some in go-fast red that was just about 1mm thick. The ebay vendor I used was siliconesupplies, but I'm not sure they ship to the rest of Europe.

Very nice little pocket light there

I wish that I could share some photos of my lumen maker, but the patrons that commissioned it want to keep it a bit under wraps for now.

It has much in common with your device. It is built around 15,000 lumen/150 watt (30V/5A) Bridgelux LED arrays in independently controlled modules. Each module has it's own AVR based driver/dimmer/thermal manager/fault manager. They talk to each other and a central control via a RS-485 network. Forced air or liquid cooling though... each module is less than 50 cubic inches. Input power is via a dual-redundant failsafe power supply with 2x16P 20Ah A123 LiFePO4 battery backup.

The biggest configuration so far is 180,000 lumens in a 12 module array. There is talk of doing a 540,000 lumen beast. There is currently a limit of 65,535 modules in an array (but that could be changed) so there is capability for a little more expansion.

Very cool. I do a lot of controls stuff, so RS-485 is one of my love-hate relationships. Nice job, it sounds..

PPtk

I have been SWAMPED at work, an out of town quite a bit, so I haven't put one second into my big light.. Too bad, but I can't do fun projects like this one without the income that working generates :)

In the little bit of free-time that I have had, however.. well, ask and ye' shall receive..

PPtk

watchingwaitingFoy

Sexy time.