making the new NUBM44 450nm diode handheld?

Mohrenberg said:

Building it yourself is the best part though!

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ya but when it comes down to understanding the science behind it and the technical issues you have to wonder and think about is this going to be the safest for me and the diode. Those diodes are not cheap and one wrong move and poof its toast. So that is were that suggestion came in. Its not that I doubt your building skills but if your asking for advice on that diode is were the rational of having some one that knows how to build those monsters comes in

Mohrenberg said:

You could also use the SuperBoost driver set at 4.5A and power it with a single lithium battery

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Bingo. I have a big host with a BIG copper module/heatsink and a SuperBoost driver laying around. All I have to do is order the diode. I am so close to ordering. I really need to get rid of some of the ones I have now before I make the purchase, but I might go ahead.

What's missing here is you are showing what you believe is the max output for the blue diode and completely throwing out that many of us have 520nm at 1.5W and NOT "just" 1W.
If it turns out to be 462nm you would need over 10W to equal the 520nm in beam and more than 16W for "dot" Any drop in the blues wavelength and the difference is much more dramatic. 12.6W at 450 beam and almost 23W dot.
IF you could push it hard enough to hit 470nm at 7.8W then the beam would be about equal but the dot would still be 34% brighter.
Personally I would rather have 50mW+ of 594nm than a 7W blue but price wise that's a lot of blue for the $ and I'm looking forward to adding one to my collection of lasers that just sit in cases and are rarely turned on lol

LeviathanBaphomet said:

Alaskan i do not believe you are not showing the diodes true potential with those brightness comparisons and here is my reason for believing so:



This diode appears to be slightly higher in wavelength than the 450nm/460nm brightness you have compared giving it a noticeable boost if true. I ordered it set to 5500mA and with DTR's tests showing it is almost certainly outputting 7+ watts.


And with Mattronium's (maybe unrealistic prediction) there is potential for as high as 7900mw @ 5500mA.

Knowing it can hit 6830mw without problems, and a theoretical high point of 7900mw here are some reconstructed results.

Are my new comparisons really any more valid or am i just throwing numbers around with unproven information? I think until the true wavelength and peak output tests comes back we can't know for sure.
Having purchased one, i may be bias to hoping it's on the higher end of the brightness scale which would be a pleasant result!

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There's a new video of a highly controlled NUBM44 setup. It only hit 4 watts, and it wasn't 462nm. I'm hoping he got the wrong diode somehow. Lol.

TaterMay said:

There's a new video of a highly controlled NUBM44 setup. It only hit 4 watts, and it wasn't 462nm. I'm hoping he got the wrong diode somehow. Lol.

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He is only getting 4 watts because of all the corrective optics he is using. If you watch the whole video he shows how small he can keep the spot size to at a distance. If he didn't have the beam passing thru all of those optics it would be hitting 7watts

Well look at the other thread on them. Looks like it's more likely 450nm. It's a really decent deal and very powerful and I'm not saying anything against them at all. I want one myself to add to my collection. We are also strictly looking at the calculator and some people see different Wavelengths better than others besides for the large number of other factors involved (such as beam width). My comments come strictly off of the calculator because that was used to compare.
I can say personally that my 1.5W 520nm is no contest way beyond my 3.5W blues and i have nothing stronger to compare to right now. We'll just have to see when I get one if I think differently.

Ah, I'll have to watch it again when I have time. I thought he was saying he wasn't using corrective optics in the initial power measurements. Funny, all that money in that setup, and it's the least accurate measurement of actual power we've gotten so far. Regardless, I want a setup like that. So bad. Lol.

Haha...he burns his hand at 17:20! And, where the hell are his goggles?

Has anyone done a side by side of the 7A75 vs NUBM44 as far as divergence? I have read test results comparing it to the old 7875 but not the 7A75.

RedCowboy said:

Has anyone done a side by side of the 7A75 vs NUBM44 as far as divergence? I have read test results comparing it to the old 7875 but not the 7A75.

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http://laserpointerforums.com/f65/nubm44-6w-450nm-laser-diode-94119.html First post.

doubleone44 said:

http://laserpointerforums.com/f65/nubm44-6w-450nm-laser-diode-94119.html First post.

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Yes I saw that, it's one of the things that convinced me to buy one. But I wonder if anyone has measured them with lenses installed and focused to infinity at a given distance.
Planters posted this info: At 50cm from the front of the collimator lens, the "3W", 9mm beam is 3mm high and 2mm wide. The beam from the NUBM44 at the same distance from its collimator is 3mm high and 7mm wide.
So what I want to know, because I never bought a 7A75 because of the divergence is how it compares when focused with a 3 element lens at 10 feet.
From what I saw comparing the 7875's raw output to the 7A75's raw output was about double, but the NUBM44 according to Planters data seems to be 350% spot size when focused at a given distance.
Nowhere have I found data on the 7A75 vs the 44 as far as focused spot area at a given distance with the same lens, at least not in measured numbers.
From what I gather the 7A75 is about 2x the spot size of the 7875, the NUBM44 seems to be 3.5 times the spot size of the old 3w 7875.
I have read a lot but have not found it in exact numbers, have you? Thanks.

Well, if spot size is twice as big, divergence should be twice as high too, even collimated.
Given that the spot size of a NUBM44 is 3.5/2=1.75x as big a 7A75, divergence should be 1.75x as high too? I think? I haven't seen any exact numbers either, we might have to poke DTR on that

Gadget said:

Haha...he burns his hand at 17:20! And, where the hell are his goggles?

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You can make do without them just fine if you have the laser bolted in place or secured somehow and you know where the output is going.

Hiemal said:

You're misunderstanding a few things, I think.
The laser diode itself requires about 4.7 volts at 5.5 amps, if I remember DTR's testing correctly. Now, what you can power that with just depends on what kind of driver you're trying to use.

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This actually sounds like a reasonable fit for 2 18650 cells in series with a linear regulator.

At such current levels the output voltage from the cells will probably sag a fair bit under their nominal 3.7 volts each. If something like 3.0 volts a cell remains there would be room to work with for a properly designed linear regulator.

Bear in mind that all of this will be dissipating A LOT of power and will require proper heatsinking for both the diode and the regulator. The diode alone dunks 25 watts of heat, and a linear regulator may add 10 watts to that.

Making something like this portable is mostly a matter of thermal design, not an electrical issue. No matter how you make it, it will be blasting out at least 30 watts of thermal power, which is too much for common 2x18650 style flashlight bodies.

From an electrical perspective building it is not that difficult as transistors that can handle this amount of power and current are readily available provided adequate heatsinking is present.

The diode is outputting part of that 25 watts as light, so it isn't ending up as heat dissipation. The way you worded part of your post seemed to indicate the heat sink would need to handle that much dissipation.

My testing shows anything above about 4A isn't very helpful, and power starts decreasing soon afterwards. That's ~19W in, 6W out, and 13W to dissipate. Typical switching regulators can be 85% efficient or above. A total thermal load of 15W isn't outlandish at all for an aluminium flashlight case.