What did you mod today?

From datasheet: “…configurable to 3 V, 6 V or 12 V by PCB layout”
And yes, you are right Scallywag, 3V is different led but should look the same as 6/12V. Datasheet have misleading info. How to configure 3V led using MCPCB to 6/12V ? :smiley:
And if its “boost” driver, so why its programed to behave like buck… whats the point!?
Is it so hard to measure voltage on led output? :slight_smile:

Modded my SST40 S2+ driver to drive at 7A. The SST40 really didn’t like that! It went an angry blue. Changed the driver to a stock 5A driver but I have a feeling there is more tint shift then there used to be.

I thought the SST40 didn’t mind being driven at 7A?

Those shouldn’t mind 7 amps. I’d double check to make sure there’s a proper amount of thermal paste and proper contact between the MCPCB and the shelf.

Yup there is, I put new paste on it. I noticed it whilst cycling through the brightness and instantly turned it off. It was on that brightness for maybe 1-2 seconds. Might just be a bad version of the led. It’s a few years old.

Bad reflow maybe ?

Yeah I was thinking that too. I might just reflow it once my heating element arrives.
That or turn this one into a triple too.

Still much love for the MT-G2.

Today’s build is a Convoy S21A with MT-G2 5000K 2-step.
This just reminded me how nice is MT-G2. Although it’s not high CRI the milky spill it creates is just awesome. In shallow reflector of S21A it makes a great floody pocket flashlight.


Amen to the MT-G2. Not the most efficient one out there but still my all time favorite.

Nice MT-g2 build 1stein! did you open the reflector up at all to fit the big led, or it just worked out how you wanted it to?

Nice build — I might have to build me a 4000k version — what driver did you use — How’s the heat

Thank you! Yes, I’ve enlarged the emiter hole in the reflector to fit the LED. Furthermore I’ve put the special gasket to make the ref rest on it instead of the led, so the MT-G2 edges are secured. Everything took like one hour so it wasn’t very hard to achieve.

Beautiful, very under used LED.

Noice. Wish I knew which drivers play nicely with the MT-G2. Hardly any real spex for max/min output voltages, how it’s regulated, max current, etc.

I recall from MtnElectronics that it's a 6V LED.

Well, the rated voltage can be gotten from the datasheet. They were made in 6, 9 and 36 volt versions. Cree states 3000 mA max , but is there an old thread where someone has torture tested one?

I have not searched

I have a Olight SR 51 modded with a fet driver zenner — 6v MTG2 — it hits in the 9-11 amp range — gets hot enough to cook a meal but the LED has held up for years

They can be 6V/9V/36V, iirr, depending how they’re wired internally. I think I got the 9V types.

Hang on…

Yeh. https://cree-led.com/products/xlamp-leds-arrays/xlamp-mt-g2-easywhite

So with the XHPs that are 12V or so, the driver might not be able to still regulate outside its designed-in voltage. Might not be able to hit high enough voltages for, say, 18V strings (let alone a 36V MT-G2), and might have issues trying to put out a too-low voltage at 9V, thinking it’s a short.

And a 5A driver would be Really Bad for a chip that can only handle 2A on the books but maybe 3A if well heat-sinked.

So… I don’t want to fry one of my precious stash with a driver that cooks it, or don’t want to waste it if the driver can’t put out a decent amount of current.

I wouldn’t want to torture ’em. At 18W, even at 100lm/W, that’s 1800lm, which ain’t bad at all.

Credit:djozz (obviously :beer: ) Nichia 144A series, an output test of a 6500K 70 CRI sample. Nov 7th: added a test of a 5700K R9050 version of the 144A

MTG2 can still hold its own. I have two 4000k installed in a K40M and a TF C10.

I have a few P0 5000k 6v emitters in my stash if anyone wants one

Note that MT-G2 is still available to buy :slight_smile:

BG has 2 pcs left (here),
or at INTL-Outdoor (can’t reach their site ATM)