YEZL Y3 CNQUALITYGOODS Group buy. 3 Versions. See post 274 for delivery details.

Not sure this will work, but here’s a link to a short video…

Yezl Y3 MT-G2

I’ve had dies on XP-G & XP-E debond from the substrate they sit on, so pressure on the dome was required for them to light up. Recently I ran into the flickering you describe, but with an XM-L. It only happens at higher drive currents. I assume that this problem is due to the dies debonding like I ran into in the smaller emitters. Nice photo BTW!
EDIT: and of course with the XM-L there is only a single die, so I assume that the entire die was flickering on and off. I did not look at it through wielder’s goggles though, so I do not know for certain.

It’s a buck driver, do not bridge sense resistors. No discussion needed, if you never bridge the sense resistors on a buck driver you will not miss anything. There is nothing good that bridging can do which resistor mods can’t. I assume you’ve bridged the wrong ones or you are running on 1s. In order to properly fry your LED, bridge the larger R150 and R180 resistors. This should poof the emitter immediately on 2s. My suggestion would NOT to do that and instead calculate new sense resistor values and do a resistor mod. Use this formula to establish the total resistance you need:
R = 0.250 / I

So for 5A drive you would have:
0.250 / 5.0 = 0.05 Ohms

And in turn you can plug that into a reverse parallel resistor calculator in order to figure out what two resistors will allow you to achieve your desired sense resistance. In this case there’s no need… for 5A you’ll just want a pair of R100 (0.1 ohms) in order to generate 0.05 ohms.

Ah thanks guys. That helps wight. I’ll give it a shot. The amps at the tail didn’t change much, so replace them both to smoke it. Yeah I am running 1 side then. That shouldn’t be a problem to fix =] I like the formula it’s simple. Should work good in future mods too. :slight_smile:

Thanks… Appreciate the help

4wheel- I’ll have to play with the focus. Maybe make a little bridge on top of the centering ring

I’m not sure what you mean by “I am running 1 side then.” The notation 1s is for “one series cell” in this case. Are you running a single cell or two cells? Did you bridge either of the two parallel sense resistors? I would have expected bridging either resistor while running 2s to poof an XM-L2. The given formula only applies to QX9920 based drivers (those drivers which include a SOT23-6 chip marked “LEDA”). Other buck controllers will use different sense voltages. The formula is easily adapted in that case - simply replace 0.250 with the sense voltage, so a 205mV sense voltage would be 0.205.

I’m curious to hear how the focus works out.

Tom E wrote:

ImA4Wheeler - cant' get to that link - direct post links don't work for me anymore. I do have it posted in google drive somewhere... Should be here: https://drive.google.com/file/d/0B1IxYZuk4DjcbzI2S1UyYVpjbGs/edit?usp=sharing

Thank you. Look forward to trying it out. :)

Have to go down today and pick up some chipquick. Well that’s the thing, I only bridged one of them, so if that’s the reason it didn’t go poof, I’m happy with that. But reading the amperage going through the tail, was still under an amp with 3 cells? It barely moved after the bridge. I’ll let you know how it goes when I pull those 2 out and have the new resistors in. It’s actually been awhile since I did this kind of work :slight_smile: I have land and farm nowdays. The drought in the valley is causing all kinds of havoc right now, we lost all ground table water and our well isn’t deep enough, so I have had some time on my hands lately. You can’t water if there’s no water. They won’t open the delta up to help us because environmentalists say there’s a rare smelt that is endangered. That’s the emergency system for these matters, all infrastructure is there, just needs to press a button to help us. Instead all the water is going out to the ocean. Sometimes I think eggheads should stick to what they know and stay out of politics. I mean smelt are everywhere, they forget where their food comes from I guess. A lot of the perennials are lost here in the valley, they take years to grow back. The guys who saw this coming drilled deep wells years ago, they are laughing at us all!

I couldn’t even find my solder, have to pick up some SM60 today too.

Actually that makes sense now. Thanks… If I can get this light useable to where high is decent, can use it out there nights. It’s not going to sit on a shelf. I’ll send one to my brother in law too, see how it compares. The supernight I just colored in one resistor until I had it at 4 amps through the tail. That seems to be the perfect balance with heat. This light I figured (well don’t know what I was thinking lol) I bridged and see where it ended up at. Maybe I should stick to pencil or soldering in resistors the right way instead of being crazy :slight_smile:

Should add I’m using protected 5200mah cells. Just took off the wrapper and removed the button top on the + end so they fit.

Hey fell. I haven't kept up on what you have done to your light. If you bridged one sense resistor, the whole bank is essentially shorted. Copper wire might get you a little more, but isn't 3 amps at the tail about 9 amps (less driver losses) to the emitter (if you still have a xml in the light)?

He said one amp at the tail.

I am skeptical about the bridge. There is nothing about this driver which leads me to believe that a bridged sense resistor wouldn’t pop XM-L2’s on 3s. One amp at the tail on 3s is about right for a completely stock driver. Plus, fellfromtree even commented that it didn’t seem to change much. Without being there myself I’d say that the resistor was not successfully bridged.

Oh sorry guys… Anyways here’s the resistors I’ve swapped. Are these the ones? It changed nothing sigh

Here’s the O ring I tried to keep pressure on the de domed u2… That didn’t work too well either

Hopefully those are the wrong resistors.

Edit

Well think found the problem. I might have used to much heat in the transfer. I took those 100s off a old thermostat I had from school. I have tons of electronics just junk. Taking a new set off a old video card right now, see if that fixes it. They dont sell those smd here, so I have to make due or order it.

fft - might not be a good idea to use the o-ring there - you want the LED more into the reflector, not further out.

MT-G2 Upgrade w/stock driver (CNQ group buy Y3 w/1 extension)

I added an 0805 size R100 resistor, swapped the LED out for a MT-G2 I had laying around (not sure of bin - think it's an original IOS version), nice neutral tint. I measured 4.6A at the tail with two protected KP 4000's, getting a nice 2186 OTF lumens @30 secs, even though the reflector is rattling (loose).

Then swapped the lens for a UCL/p I had, them measured 2,329 OTF lumens @30 secs (it loses bout 120 lumens from start). The UCL/p is a little thicker at 2.25mm, while the stock lens is 2.02 mm, so less rattle now but it's still there. I screwed down the MT-G2 Noctigon, used GC Extreme under the Noctigon and sanded surfaces smooth, carefully got it perfectly centered, and have the reflector sitting directly on the edge of the MT-G2, extended the wire solder pads out by using copper extensions, so the reflector sits pretty low. Also I kept the stock 22 AWG wires, but probably should use 20 AWG. 22 AWG wires in both springs.

A better fix would be to raise the Noctigon by reflowing it onto a copper shim - that should get the reflector sitting tight on the MT-G2, maybe use some kapton tape to protect the MT-G2 edge - I think this is another risk factor of having the reflector sitting directly on the edge of the MT-G2 emitter.

This needs more testing, it does get warm pretty quick as expected, and probably could benefit, and survive better by potting the driver, as 18sixfifty's thread "Are you on Pot?" describes very well. Didn't measure throw, but in testing it outdoors, it looked pretty good against my SupFire L6 with a XM-L2 T6 4C and a BLFDD driver, but throws a big spot of course.

I'm kind of impressed this was so easy - no idea the stock driver would so easily support an MT-G2, just hope it's reliable - didn't check for hot SMD's on the bench... I'm glad this capability was pointed out earlier in the thread.

Edit: measured throw: 43.5 kcd measured at 5 meters

Note: all my lumens and kcd measurements are my own taken on a older LX1330B meter - kcd taken indoors and lumens in a PVC constructed lightbox, accuracy can be freely debated Smile (CYA all the way...)

Hehe nice Tom… Mine actually went the other way. I now have .03a at the tail on high using 3 batteries. I’ll mess with another set of resistors tomorrow. I had things to get done today too- my other half is mad… Like fack a flashlight mad. I noticed that about the emitter though. Does do better inside the reflector. I’m just gonna have to order a set of smd resistors it looks like.

100 and R100 are not the same thing. The “R” is a period, so R100 = .1 —- get it? I don’t remember ever disassembling a thermostat, but I doubt that it had an R100 in it. If you replaced the stock sense resistors with a pair of 100 ohm resistors then you are getting approximately the right current (seems a little high, but the formula is less accurate when you take current so low).

“They” don’t sell SMD resistors “here” either, we all have to order them over the internet except maybe ryansoh3 I suppose. Mouser or Digikey are the fastest way for those of us in the USA / North America, Fasttech is the cheapest source for a couple of values in 1206 size and several more values in 0805 size. Maybe you should establish exactly what you are trying to do and order the appropriate parts. At this rate you’ll kill something soon. Note that nobody is selling sets of sense resistors. You’ll need to purchase those individually, the sets are all of much higher values.

EDITed

Sounds like good work. FWIW I just want to point out that your lowest value resistor, by quite a bit, is the 0805 sized one. It’s going to be carrying nearly half the current by itself with a 250mV drop across it. Best case scenario it’s rated for 250mW of dissipation, but this is probably 500-600mW. 1206’s are probably rated for 500mW, so switching to one of those could be a good idea, even if you are going to pot it. Other than that, I assume that the baby FET is the weak point.

I have not received mine yet. Are the stock sense resistors 1206 or 0805?

Yeah we have two decent shops here. Whitcom just don’t make enough money selling smd and Sparkey’s didn’t carry R100. I can barely read those dang things as it is. I should go down to schneider electric right next door. They used to be Pelco, make surveillance equip. I’m sure one of the programmers could hook me up.

Pulled 2 off the school thermostat and that’s what I got. Yeah your pretty informative wight :slight_smile: Bought 5000 assorted off ebay for 10 bucks already. That should do it, but no flashlight messing for least 3 weeks it looks like. China shipping. :frowning:

Oh well, I tried. I’ll make my way down to Schneider tomorrow. I’d like to see this thing work so I have enough time to order another one before October.

Edit

I went through the camera, I took this after laying in the first resistor- 100 xd On low I can see the emitter clearly without sunglasses. Kind of cool in a way, like a cool white light. I really hope I can get ahold of a couple spare resistors tomorrow. I should do a WTB on craigslist too like a crackwhore looking for a fix. Wight you sure it can handle 5 amps? Or should I do something more conservative with this. I’d like to push it to it’s limit on high, probably run it med most of the time though.





I wanted to ask you guys too. Do you clean the reflector? Any imperfections are noticeable. I blew it out with compressed air and was going to take lens tissue to it- then thought, what if the chrome layer scratches or comes off. I dunno just thinking too much probably… Let me know (before I ruin it)

Dont touch the reflector. You run the risk of ruining it. Some reflectors mark by just looking at them.

Nice effort guys on the MTG-2. I have a HD2010 running at 2.7 amps and it puts out an amazing amount of light for such a small current drain.

0805's are stock - I should have mentioned that, that's why I used an 0805. So, you think these are current limiting and not current sensing? I was thinking sensing and that's why they used smaller ones, but I had no clue.

Yes, I'm thinking it could do better - reflector is probably blocking, being loose, and upgrading to 20 AWG wires may help a bit too. Without knowing the amps to the LED, hard to say it's performing at its best. But, it still looks pretty nice - love the beam pattern. Only other MT-G2 mod I did was a much smaller light, and this one is definitely brighter and has better throw by far.

Are other people still waiting on theirs? My tracking number still returns no results, track17 will recognize it as China to US but shows no info.

@FFT

I never touch a reflector over dust/ one little spec, it’s not worth it, I use my compressor to try to blow it out but that’s it for minor imperfections. For larger issues, a dirt spot / a print / oil / grease I use the microfiber cloth that came with my Chris Reeve Sebenza, I wash it [the cloth] first and the very gently wipe, not with direct finger pressure, I use just the corner of the cloth. It works pretty well, of course my preference is not to need to do anything like that in the first place but it gets the job done.

I use the same cloth for cleaning all my lenses, something about that material is perfect for getting finger print oils and other shit off AR glass and PVD reflector coatings.

Still. Ric doesn’t answer to PMs. cnqualitygoods@hotmail.com also silent. Two weeks passed from fake shipping date.