You know the story about the kid who flew too close to the Sun? Well that sums up my latest attempt with the 3xMT-G2. I thought I had it all and it could last forever flying right up into that brightest of brights, then I came crashing back down to earth.
Well not as bad as all that but it was great for about 10 minutes or so and then nothing.
I started out with the 9amp driver from IO it was extremely bright but not heavenly bright, really pretty good actually but the driver continued to overheat and cut itself back down to low. So I pulled it out and tried the 7x driver and WOW just great it was even brighter and seemed to work perfectly the modes were changing just right. I walked with it for about ten minutes, not all on high either and then POOF no more light. And I came crashing down to earth. I really thought I had it licked. The light never did get really hot either and it hadn’t cut down to low like it should have if the driver was getting hot. It just simply fried and died. So I walked back home opened it up and smelled the acrid burnt driver smell of defeat.
So now I have the 9amp driver back in and tried to do a better job potting it hopefully it will work better, I would really like to be able to run this on high without it dropping down. You can bump it back up to high using a double click but it’s not ideal.
I will say this, it’s still a ton of lumens and the beam is great, it has a bit of throw with a noticeable hotspot. The flood is the nicest big flood I have ever seen. There are zero rings with a very even nice flood that covers a HUGE area. It just lights up my entire back field.
I have a new light meter showing up tomorrow and I’ll try and add some beamshots tonight if anyone is interested.
So although I got burnt flying too close to the sun I did survive to fly another day.
Thanks for the story. Now get back into that space shuttle! :)
When it comes to driving 3 MT-G2s, the 9 amp IOS driver does not do the job due to overheating and diming down (or getting locking in high). You, MRsDNF and Comfychair have basically confirmed that. I don't think potting the 9A driver will do the trick. But please prove me wrong.
Now you have burnt the 7 XM-L boost driver, what is left if you want a decent driver?
I wonder who will use 3 driver circuits first and get 4A++ to each emitter.. >)
Edit: I also wonder if the 9 XM-L boost driver would have handled it better. But dont blow on up for my sake. Its probably pretty much the same as the 7 XM-L version.
I really don’t know but I thought I had it with the 7x driver and I also thought it would be able to handle it. It’s actually supposed to handle up to 9x I wonder if it was a problem with the driver? It was perfectly seated so I am 99% positive there were no shorts or anything like that. Unless somebody else comes up with something I think I’m dropping out of the space race for now. I’ll probably just pull it apart and turn it into another XM-L2 de-domed. I’m sure I can find something to do with the parts.
I put my 3xMT-G2 build through its paces while on vacation. The LusteFire pumped out almost 5000 lumens for about 20 minutes and didn’t overheat. It was a cool evening, but I think it did quite good. I think it would have run for the full 35-40 minutes to deplete the 3x26650 4000mAh cells. I’m happy with it.
What was I doing with a 5000 lumen light? Spotting squid off a pier. My father and I took my son squid fishing. The light was too bright and tended to scare the squid at first, but they got used to it after a while. He managed to catch two small ones and had a great time staying up past his bed time.
I used a J-19 The host handled it fine just the drivers didn’t though. I saw your build but I have no idea how to stack resistors and don’t think I could do the soldering if I knew what I was doing. Any other suggestions or should I just live with the dropping out. Like I said if I do a quick double click it seems to work but really it’s annoying.
Thanks for the report 18650. It was interesting to hear that your driver dropped back to low as it is meant to. Mine running a single MTG-2 did not. It would flash to low and straight back into high and continue to do this. It would not allow you to change mages and did a similar thing on medium except did not flash, just get stuck in medium. The only recourse I had was to turn the light of until it cooled down slightly. At 9 amps a single MTG pumps out enormous heat very quickly. At 5 amps it is still incredible how much heat is put out.
Thanks for the info. So this driver isn’t going to work for MT-G2’s at all. Bummer.
At three amps each the heat isn’t too bad but unless someone knows of a better driver to use I’m taking it apart and making three singles out of the parts and the J-19 into another de-domed monster. I sold one and have another one on the way. I only really bought it so I could have one of each. But this one the way it is just doesn’t work for me.
I've gone over the IOS driver with a hand lens looking for something that might be a thermistor, but there ain't one. It must be integrated into one of the... whatevers. The overheat protection on those is way way too conservative but I don't see any way to disable it. :(
I've had my 9A driver disassembled for a while now, I need to piece it back together and run it with the driver outside the light, see how much heat is from the driver itself and how much is the driver picking up heat from the LED. Other than that temp (mis)monitoring it's a great driver...
Aww, thats no good, J-19 with 3xMTG2 cant fail! You did save me having to buy it off you for now though, and having to explain a large flashlight purchase…
It has to be from the driver itself. It’s not on long enough to get hot from the emitters. The heat doesn’t even get a chance to build up before it drops down. The thing that got me about the 7x driver was that it didn’t drop down and instead just burnt out. I didn’t expect that at all. This is the third one of these drivers that I have used and the other two dropped down with no problem at all. Well other than dropping down quicker than I would like them to. So far the best build I have done with one is a 6xU3 that light is just unreal bright and it runs on that driver really well.
Do you know if there is any difference between the 7x and the 9x drivers from Kaidomain? They seem like they are all the same to me.
Yep it’s a bummer but I was afraid it might turn out this way. These MT-G2’s pull so much power it’s unreal. I don’t know the numbers or even how it breaks down but the XM-L2’s seem to be more efficient to me.
I don’t know about efficiency but in the same reflector light the MTG is an absolute flood of light compared to a skinny little beam from the XML-2 not that we would of said that six months ago. In throw the XML-2 is in its own league.
My guess on the thermal protection is an integrated temperature sensor in the MCU. Most small MCUs made in the last 8-10 years include one. In most cases not overly accurate, but good enough to protect from overheating.
I guess in some cases, the driver designer went a little cautions on the cutoff temperature.
The LusteFire driver doesn’t appear to have any intentional thermal cutoff, although I figure catastrophic ‘cutoff’ would occur if left on for too long with no cooling. I’m not sure if that driver is available from anywhere on it’s own. Would be interesting if it was, or was requested through a certain popular online store
Living with the step-down may be your only option until a driver can be sourced. There’s are not many drivers available that can deliver a sustained 50-70W of power.
It’s a shame but I don’t see any good options, so I think I’m just going to pull it back apart. Too bad the 7x driver burnt out it was a thing a beauty while it lasted. What gets me is that although it was bright it still wasn’t as bright as my 6xU3 and it runs fine on the same driver. I wonder if the driver itself had a defect and that’s why it didn’t drop down or possibly something else wrong with it altogether.
Well does anyone need a 9amp driver? I have one to sell you cheap.
Three h6flex Taskled drivers, Master/Slave, set at 6600mA per led. I'm considering it. I talked to George about it. It's feasible, but it might be too much for the Master at 6600mA each, It should be good at 5000mA each.
Someday when I got $125 to buy drivers, but I bet it would be a kickass light!