NUBM07E 465nm 2.9W Diode Test (Hitting 470nm+)

[Alaskan]

Well, I am now undecided, should I run at 4.5 or 4 amps? Got a PM saying better not to push it to 4.5 amps at the current prices. What mechanism causes the wavelength to change if pushed harder anyway? Googling I can't find the answer yet.

 

[RedCowboy]

Well, I am now undecided, should I run at 4.5 or 4 amps? Got a PM saying better not to push it to 4.5 amps at the current prices. What mechanism causes the wavelength to change if pushed harder anyway? Googling I can't find the answer yet.

It's the current that drives the spectral shift not the temp, if you look at the charts on page 1 you will see the knee is at 4.0 amps.
You can get a few more nm past that but you are going to be making lots of heat and no more power.
Personally I don't think it's worth it to go past 4.0 amps.
You are going to see plenty of difference over 445nm at 3.5 amps.

 

[TaterMay]

Well, I am now undecided, should I run at 4.5 or 4 amps? Got a PM saying better not to push it to 4.5 amps at the current prices. What mechanism causes the wavelength to change if pushed harder anyway? Googling I can't find the answer yet.

Cyparagon posted this earlier in this thread:

Yes. It's current - independent from temperature. I've verified this personally by pulsing the current between low and high and watching the output on a spectrometer. The Wavelength changes instantly in step with the current.

The wavelength changes very little with temperature. Not on blue/green/violet anyway. Red and IR diodes DO change rather drastically with temperature.

 

[RedCowboy]

I ordered one today with a driver set to 4.5 amps through DTR's LPF Google store, lets see what this one looks like through my 2 inch/50mmn expander on a dark night

I would have gone to 4 amps, but want to push it harder hoping for closer to 470nm.

This is @ 3.5 amps through a home made sliding beam expander.

EDIT: I have deleted the pics because bing search had a tag attached that I don't know where it came from but it sounds bad, I will not repeat it here.

 

[Alaskan]

Thanks for the info everyone. Going to put the NUBM07 in this Ehgemus host standing on end and get some beam shots for you.

Thanks for sharing the photo's cowboy, I've done lots of taping of expander optics to my pointers too

 

[RedCowboy]

Thanks for the info everyone. Going to put the NUBM07 in this Ehgemus host standing on end and get some beam shots for you.

Nice toys.
It's taped cardstock around a mounted vis coated lens, but it slides to adjust the focal point and to be fair what I'm using is not really a beam expander, the beam is already expanding out of the diode, this is just a much larger lens with a longer focal length that lets me slide focus to a pretty tight little rectangle.
The beam exits at about 25mm and I can burn a hole in a cardboard box about 8 times as far as with a 3 element, which figures as the 3 element has a 4mm FL and this is around 30mm FL.
Like a lot that I do it's crude but works, I need to put it into a aluminum tube.
Before I make an adaptor for a real beam expander I want to fully correct this beam and put it into a nice host.
Yours is very nice.

 

[crazyspaz]

Sorry I didn't see your question, been busy.
No my driver is mounted in it's own housing behind the diode module.
But I do have mine with a regular aluminum back because I used big wire that wont fit through the solid copper back hole and drilling it out would take out most of the little copper pedestal that makes the thermal contact with the diodes back.
What I did was I filled it with heat sink putty to thermally bond the back of the diode to the 12mm aluminum back half.
It's working like a champ, awesome color and a good burner. The divergence is better than the 44 diode as well.
The solid copper backs are a good idea, they work best with the silicon wire DTR uses, but I would also put a little heat sink compound around the pedestal to make contact with the rest of the back of the diode if you are pushing them harder than 3.5 amps.
Want a laugh?
My original host had a little spring pcb battery board that decide to develop an intermittent open, after tearing it down twice and discovering it was the board I gave it the hammer treatment and put the works into a big ugly caveman portable test host.
Point is the aluminum back half filled with heat sink compound transfers heat just fine as I run this ugly host for many minutes and it all gets warm like it should, but the full copper back lets you take it apart and is the way to go.

How much filled? Heatsink compound isn't literally heatsink compound, its meant to fill very tiny areas between surfaces for a solid connection. If you just dumped a bunch of compound in a big empty space, all you did was waste a bunch of money.

 

[RedCowboy]

How much filled? Heatsink compound isn't literally heatsink compound, its meant to fill very tiny areas between surfaces for a solid connection. If you just dumped a bunch of compound in a big empty space, all you did was waste a bunch of money.

I cut the back out of the aluminum can/module back, put a little paste on the back of the diode and pasted on a hand made copper plug cut from 1/4 inch stock with a hole big enough for my wires that are insulated with heat shrink tubing, covered the plug in paste, slipped over the aluminum can and filled it all the way up from the open back using little sticks to pack the paste in around the wires, I also wiped paste around the inside of the can before sliding it over the plug and screwing it on, I let is sit for a few hours until it was firm.
The paste I use is not expensive yet it works well, it comes out like thick toothpaste and dries to firm/rubbery clay.
I do not recommend this over the full copper back half, I prefer the solid copper back half, I just didn't want to un solder my diode from the too large for the copper back size wire I used.
The truth is I screwed up by not checking the solid copper back half hole diameter before attaching my wire, that's usually not an issue and I almost always drill out the back of my cans and paste in plugs.
But now that the copper backs are available I plan to use those or square box mounts that contact the diode back.

Thanks for looking out crazyspaz :beer:

 

[crazyspaz]

I cut the back out of the aluminum can/module back, put a little paste on the back of the diode and pasted on a hand made copper plug cut from 1/4 inch stock with a hole big enough for my wires that are insulated with heat shrink tubing, covered the plug in paste, slipped over the aluminum can and filled it all the way up from the open back using little sticks to pack the paste in around the wires, I also wiped paste around the inside of the can before sliding it over the plug and screwing it on, I let is sit for a few hours until it was firm.
The paste I use is not expensive yet it works well, it comes out like thick toothpaste and dries to firm/rubbery clay.
I do not recommend this over the full copper back half, I prefer the solid copper back half, I just didn't want to un solder my diode from the too large for the copper back size wire I used.
The truth is I screwed up by not checking the solid copper back half hole diameter before attaching my wire, that's usually not an issue and I almost always drill out the back of my cans and paste in plugs.
But now that the copper backs are available I plan to use those or square box mounts that contact the diode back.

Well like i said, filling it with compound does absolutely nothing. But that's fine if you have a copper piece touching the back of the diode, as long as said copper piece makes good contact to the module (i.e. if you have a mm between the slug and the rear aluminum module and it is filled with paste, that's not doing much).

 

[Glutton]

I was testing something like this the other day with Fujik thermal compound which I used to fill all the space in my C6 module (a direct press design not an Aixiz) after heat sinking the back of a diode with copper plates and driver the same way. I Found that it does actually work better than I thought. To test it I used two all copper pennies and pasted them together with about 5mm think paste between them and let it dry. When I applied heat it was conducted from one side to other pretty damn fast. After about 5-10 seconds it was difficult to tell which side was the one I applied heat to. All in all it was definitely much better than just leaving air in the extra space inside the module.

Well like i said, filling it with compound does absolutely nothing. But that's fine if you have a copper piece touching the back of the diode, as long as said copper piece makes good contact to the module (i.e. if you have a mm between the slug and the rear aluminum module and it is filled with paste, that's not doing much).

 

[RedCowboy]

I was testing something like this the other day with Fujik thermal compound which I used to fill all the space in my C6 module (a direct press design not an Aixiz) after heat sinking the back of a diode with copper plates and driver the same way. I Found that it does actually work better than I thought. To test it I used two all copper pennies and pasted them together with about 5mm think paste between them and let it dry. When I applied heat it was conducted from one side to other pretty damn fast. After about 5-10 seconds it was difficult to tell which side was the one I applied heat to. All in all it was definitely much better than just leaving air in the extra space inside the module.

Good test.
I have had nothing but great results with FUJIK B.A.B. 900 compound and it is not expensive, it also dries to provide mechanical mounting. You can't drill and tap it or anything but it will hold a driver in place.

 

[TaterMay]

Well like i said, filling it with compound does absolutely nothing. But that's fine if you have a copper piece touching the back of the diode, as long as said copper piece makes good contact to the module (i.e. if you have a mm between the slug and the rear aluminum module and it is filled with paste, that's not doing much).

I am curious as to why you think filling an area with a thermally conductive compound rather than air, a thermal insulator, does absolutely nothing. Its sole(edit: main) purpose is filling in gaps between thermally conductive materials. If you can use it, it is almost always worth using. There are some cases in which you might not want to risk getting it on certain components, but it is almost always beneficial to fill in any gaps with thermal compound.

 

[Cyparagon]

Its sole purpose is filling in gaps between thermally conductive materials.

Yes, a gap of a few microns. The conductivity of the paste is actually very low. Low enough that it does virtually nothing over spans of several mm.

 

[Jstr]

Its sole purpose is filling in gaps between thermally conductive materials.

It's not. If it's what I think it is, it's also very important that the compound is an electrical insulator. Which somewhat limits its effectiveness as a thermal conductor.

 

[TaterMay]

Yes, a gap of a few microns. The conductivity of the paste is actually very low. Low enough that it does virtually nothing over spans of several mm.

The test below was much more than a few microns. I will set up a test myself tonight using my thermocouple to record actual data, but I expect it functions much better than some think when covering more than just sub-mm gaps. Only one way to find out!

Any suggestions for a good, controlled test? I have a bunch of Arctic Alumina thermal compound and adhesive, some Arctic Silver compound, small aluminum and copper heatsinks, a thermocouple/digital thermometer, and an IR thermometer.

I was testing something like this the other day with Fujik thermal compound which I used to fill all the space in my C6 module (a direct press design not an Aixiz) after heat sinking the back of a diode with copper plates and driver the same way. I Found that it does actually work better than I thought. To test it I used two all copper pennies and pasted them together with about 5mm think paste between them and let it dry. When I applied heat it was conducted from one side to other pretty damn fast. After about 5-10 seconds it was difficult to tell which side was the one I applied heat to. All in all it was definitely much better than just leaving air in the extra space inside the module.

It's not. If it's what I think it is, it's also very important that the compound is an electrical insulator. Which somewhat limits its effectiveness as a thermal conductor.

Yea, "sole purpose" was a very poor choice of words. Lol. Definitely important that it is an electrical insulator.

In other news, I'm building my NUBM07E laser tonight! And the NUBM44 also. Gonna be a good night.

 

[RedCowboy]

In other news, I'm building my NUBM07E laser tonight! And the NUBM44 also. Gonna be a good night.

Are you running your 07E with the Gball on or off?
If off and you have a LPM can you chronicle it's output over the weeks ahead, I would like establish some solid data.