2.4A Driver for XP-E2

Cereal_killer · 2019-01-16T02:39:30.000Z

The 1206 resistor marked R180 is the sense resistor. Adding another resistor on top (lowering total resistance) will raise the drive current however that inductor looks tiny, it’s probably already at or even above saturation current. I wouldn’t expect to see any gains and likely you may see performance decreases or even kill the driver.

e1000 · 2019-01-16T03:25:32.000Z

FYI, 2.4A won’t give you much more brightness compared to 2A.

Lightbringer · 2019-01-16T05:40:08.000Z

I was just gonna mention that. Also, that’s cooking an E2 chip pretty hard already, so it’s probably already peaked at output or may even be on the decreasing side of the parabola, no?

Like, you won’t be gaining 20% more lumens (6 vs 5), as its output may be quite flattened already if not decreasing with more current. But moreso, the visual difference will be negligible. Switching between 2.0A and 2.4A and back’n’forth, you’d be hard-pressed to tell any visual difference at all.

Lightbringer · 2019-01-16T05:46:27.000Z

Yah, here ya go…

Emitter Test Results pt4: XML2, XP-E2, XP-G2, and Nichia219! (along with sinkpad tests) Flashlight Modding and DIY Parts

Folks, Long time no see... Since most of you are now aware of my testing procedure, I'll be brief here. The following is a test of the Cree XML2 on a standard aluminum 20mm star, along with another xml2 mounted on a copper sinkpad. (member vestureofblood was kind enough to send me out these for testing). [image] Graphs speak louder than words, so here they are. The first one is the XML2 on a standard star, followed by a comparison graph between a standard aluminum star and a copper sink…

On an Al star, it’s already peaked at about 1.8A and light output will decrease with more current.

On a Cu star, the difference on the graph is 460lm at 2.0A, and 480lm at 2.4A. 400mA more current (20), only 20lm more light (4).

GUARANTEED you wouldn’t be able to tell the difference visually, even side-by-side.

Lightbringer · 2019-01-16T05:48:52.000Z

Similar (worse, actually) for green XP-E2s.

blue and green XP-E2, output tests Flashlight Modding and DIY Parts

[image] These tests were done already a month ago (sorry for the delay), but tonight I was finally in the right mood to type in the data, make the graph and do this write-up (I like the testing itself but it always takes some courage for me to digest the numbers and make them into edible graphs :tired: ). Thanks go to MRsDNF for donating me the red and blue XP-E2 (from Cutter, red is bin P3, blue is bin M3), and to telephoneman for the green XP-E2 (from Mouser, bin is R2), they were not easily …

Plat · 2019-01-16T06:12:15.000Z

I have made four XP-E2 lights, two of them are in identical convoy C8’s, one is running 1.9A one is 2.28A, i don’t think i can tell the difference between them (they are both red)
later when i made my green XP-E2 i just made it 1.9A again, i personally prefer the better battery life and less risk of burning out the diode compared to and extra 20 something lumen

e1000 · 2019-01-16T07:24:38.000Z

12v input, you could get a buck driver and run just about anything you want.

Snoman002 · 2019-01-16T22:15:22.000Z

It doesn’t sound like there is much point in pushing the LED harder. Hopefully a wavien helps me get the extra output I’m looking for.

Lightbringer · 2019-01-16T22:22:04.000Z

Well, whut’s it in?

If a C8 host, you can try a C8F and have triple emitters. Even keeping the same current, by cutting the current each LED sees down to a third, they’d be way way more efficient.

An HS-802 host has a much deeper reflector, and would convert a marginal amount of what would be spill (ie, wasted light), into hotspot (ie, usable light).

Lightbringer · 2019-01-16T22:26:03.000Z

And a wavien coller wouldn’t help, at least I wouldn’t think so.

For white LEDs, it helps “recycle” wasted photons by bouncing ’em back to the phosphor layer to be reemitted. For monochrome LEDs? They’d just hit the silicon and try turning the chip into a photodiode.

Snoman002 · 2019-01-17T02:02:22.000Z

Currently it’s in a Uf-t20 Aspheric. A small light with a very tight beam is the desired end state. Specifically I want to see the beam itself as much as possible, hence the green (blue would also work). It is this reason I am looking for single emitter as well.

I am intrigued to try the wavien collar on a solid color led. One of their claims was increased output on solid color emitters.

MRsDNF · 2019-01-17T02:09:12.000Z

For anyone interested djozz has tested the colored XPE2 leds. This is the link.

blue and green XP-E2, output tests Flashlight Modding and DIY Parts

[image] These tests were done already a month ago (sorry for the delay), but tonight I was finally in the right mood to type in the data, make the graph and do this write-up (I like the testing itself but it always takes some courage for me to digest the numbers and make them into edible graphs :tired: ). Thanks go to MRsDNF for donating me the red and blue XP-E2 (from Cutter, red is bin P3, blue is bin M3), and to telephoneman for the green XP-E2 (from Mouser, bin is R2), they were not easily …

Lightbringer · 2019-01-17T02:26:00.000Z

MRsDNF:

For anyone interested djozz has tested the colored XPE2 leds. This is the link.

blue and green XP-E2, output tests

Ummm, yeah. :laughing:

Lightbringer:

Similar (worse, actually) for green XP-E2s.

blue and green XP-E2, output tests

Snoman002 · 2019-01-17T02:46:49.000Z

I have the blue XP-E2 as well, just need a pill to put it on.

I am terribly disapointed Luminus has not actually produced their green. From their spec sheet it claims 700+ lumens from a 1mm2 die, FAR more then the XP-E2.

I sure do love playing with this light, lots of fun. It’s near where I want it, but the beam could be a little more solid (hence my hope for the wavien). The parts to put that together should be here tomorrow.

Lightbringer · 2019-01-17T03:20:42.000Z

And don’t forget, that by the time you zoom an aspheric to project The Bat Signal from the LED, out-the-front lumens is down to maybe a third, if you’re lucky. 300lm from the LED means maybe 100lm out the front.

That’s why a kick-ass reflector is the best way to throw as much light on the target as possible, but it generally needs to be pretty big (C8 size, ~43mm, at the very least).

At the cost of (unwanted?) spill lighting up the foreground somewhat, of course.

Lightbringer · 2019-01-17T03:21:49.000Z

Check the HS-802. Pretty cheap to use as a host, maybe 18-20bux, and like I said, a nice deep reflector to push as much light OTF as possible.

penumbra · 2019-01-17T03:29:05.000Z

Dedome your led for the uft20 and here are 2 good drivers but your must use one led on copper plate 20 mm

https://www.fasttech.com/p/5278500

https://www.fasttech.com/products/1612/10017778/4594600

MRsDNF · 2019-01-17T04:03:47.000Z

Lightbringer · 2019-01-17T16:51:10.000Z

Snoman002 · 2019-01-17T23:07:39.000Z

Lightbringer:

And don’t forget, that by the time you zoom an aspheric to project The Bat Signal from the LED, out-the-front lumens is down to maybe a third, if you’re lucky. 300lm from the LED means maybe 100lm out the front.

That’s why a kick-ass reflector is the best way to throw as much light on the target as possible, but it generally needs to be pretty big (C8 size, ~43mm, at the very least).

At the cost of (unwanted?) spill lighting up the foreground somewhat, of course.

I have gone with ashpheric to minimize spill,and from everything I am reading Aspheric throw is just as good, if not better, than reflector.

Sad to say, as close to a laser as I can get, without being an actual laser, is what I want.