NUBM44 6W+ 450nm Laser Diode

[ED KLINE]

Thank you very much, I will look forward to seeing them. Do you know what they mite cost? Ed.

 

[RedCowboy]

Another consideration is the cooling fins surface temperature ratio to the surrounding air, more fins or forced air can change the equation as can the air temp and moisture content.
As it heats up you can reach a stable operating temp if enough heat moving capacity exists.

Just like an air cooled lawnmower engine makes waste heat it reaches an operating temp where it dissipates heat as it produces the heat but not until the ratio reaches equilibrium with all the other variables.

These diodes work in machines cooled by fan forced air, some may use heat piping and a remote radiator.
Over driving these diodes reduces the efficiency and increases total heat output.
TEC cooling can reduce the diodes temp while causing the heat vehicles fins to run at a higher normal operating temp.

I like laserglows approach, a web of fins surrounding the core inside a Maglite style tube with a fan at the back.

p.s. I am also waiting for these lenses, there is a group buy that you could possibly add your name to as I believe there will be extras made.
http://laserpointerforums.com/f39/wtb-6x-cylindrical-lens-set-95047-4.html

 

[Andrew124C41]

I have written a bit about this topic previously, and it never changed:

You can make a continous operating laser if the thermal resistances beyond your control are not the limiting factor. The thermal resistance here is basically that from laser die to case, and to some degree from case to heatsink as you cannot increase the size of the case.

Lets take a theoretical example:

Laser thermal output: 20 watts (resonable for a 6 watt output diode)
Die-to-case: 1 K/W
case-to-heatsink: 1K/W

In this example the laser would operate 40K above ambient if set in an infinitely large heatsink. With a maximum die temperature of 70 celcius and ambient temperature of 25 celcius this would be acceptable.

But heatsinks are never infitiely large. So how big does it need to be? We have only 5K of room here to ditch 20 watts, requiring a 5/20=0.25 K/W heatsink. This would equate to a fairly big cpu heatsink with the fan running.

The die-to-case and case-to-heat sink values would probably a bit lower in practice allowing for a smaller heat sink to do the job, but you must obtain the exact values from the diodes datasheet to know. This will give you an exact figure for die-to-case, but case-to-heat sink also depends on what you do in terms of contact pressure, thermal compounds etc, so this can be a bit unpredictable.

I just went through something like this trying to heat sink 3 to-220 transistors on a circuit I made to to slow some PC fans...the transistors had to dissipate heat. I did not want individual sinks...just put them on one to place on the circuit board.

Wound up doing a rough calculation. Found an aluminum heat sink that was lying around roughly about the size....mounted the transistors...ultimately stuck the circuit in a bay that would hold an ssd...right in the fan stream...works likes charm.

If you look at just about any amplifier you will see that the transistors are heat sinked with aluminum with fins...simply to increase the surface area to transfer heat to whatever the ambient temperature is...your atmosphere so to speak. You don't see them made of copper. Even if you used copper, you would still need fins....and a fan if you cannot transfer heat quickly enough.

As everyone knows, the lasers are closed systems and ultimately you only have the surface area of the host. In theory, one could surround the head/diode with a finned heat sink but how would you focus?

Of course we could get more complicated and add liquid nitrogen...just kidding but I love playing with that stuff....used to keep it in the office to freeze off warts!

Liquid nitrogen...or helium....there is no resistance at those temperatures. think of the possibilities with respect to lasers...for all I know our friends at DARPA are storing up all of the available helium:evil: I am sure you guys know about the quenching of MRIs. The coils are surrounded by liquid helium. Current can run around the loop for 20,000 years....so I have been told!

 

[RedCowboy]

If I set a little pc type fan behind this one it will run longer than the batteries can stand.

 

[Andrew124C41]

If I set a little pc type fan behind this one it will run longer than the batteries can stand.

I should have known better! And, why am I not surprised
OK, for the newbie here, what do you have there...I am guessing the 445. But, how did you make it? How are you focusing it? What is the host?

Thank you! :wave::wave:

 

[TaterMay]

If you look at just about any amplifier you will see that the transistors are heat sinked with aluminum with fins...simply to increase the surface area to transfer heat to whatever the ambient temperature is...your atmosphere so to speak. You don't see them made of copper. Even if you used copper, you would still need fins....and a fan if you cannot transfer heat quickly enough.

Aluminum is typically used because it is cheaper and MUCH lighter in weight. If an aluminum heatsink with fins and a fan will meet your heat dissipation and size requirements, there's no point in adding the extra cost and weight of copper!

As everyone knows, the lasers are closed systems and ultimately you only have the surface area of the host. In theory, one could surround the head/diode with a finned heat sink but how would you focus?

You would simply have a focus adapter sticking out the front, as we do with almost all of our handheld lasers.

 

[Andrew124C41]

Re: V1 445nm Laser Diode

While not specifically helpful for laser sinking...the general idea: Heat Sink Calculator: Online Heat Sink Analysis and Design

I found this interesting: Comparing the Impact of Different Heat Sink Materials on Cooling Performance

 

[Andrew124C41]

Oh, yeah...of course...and one other thing...much cheaper!

 

[Down with Umbrella]

Quick question regarding switches of a laser with these current draw demands.
I don't shop too often at this large online electronic stores for a few reasons.

Does anyone have good suggestion for smooth momentarily switches? Metal, SPST
Sites? Digikey, farnell?
Sorry for my vague question. I am away from my go to electronic store now here in Illinois

I had this in mind
http://m.ebay.com/itm/30-AMP-METAL-...ARTER-NITROUS-BUTTON-/321897716519?nav=SEARCH

 

[RedCowboy]

Expensive, but it will be more than enough to handle the driver current to power a NUBM44

BUT, be aware of the ramp up cap in the SXD, and if you use a momentary contact and flash it on and off real fast you may bypass the ramp up and hit the diode with a sharp spike, you want the power to come up like a round wave, not hammer it like a square wave.

You can shop around and get a better deal, when I find a deal on 100 pieces of something I like I load up, they end up costing pennies a switch that way.

For the SXD to drive a NUBM44 any 5 amp switch is plenty, some momentary buttons are rated for less than a 100% duty cycle or peak current so it's a good idea to get one way over rated.
If it says 30 amps you are more than covered.
I have been burning up cheap flashlight switches with the 07E and 44 diodes so I have retrofitted better switches too.

You can use a momentary, but I would not try to rapid flash with it.

 

[Down with Umbrella]

Holy switches, you have some good collections. Gun and switches.
I have a build I will be debuting soon. But right now I'm doing the leg work.
Updates within the month.
Thanks

 

[ED KLINE]

Quick question regarding switches of a laser with these current draw demands.
I don't shop too often at this large online electronic stores for a few reasons.

Does anyone have good suggestion for smooth momentarily switches? Metal, SPST
Sites? Digikey, farnell?
Sorry for my vague question. I am away from my go to electronic store now here in Illinois

I had this in mind
30 Amp Metal Momentary Waterproof Switch 12V16MM 5 8 Horn Starter Nitrous Button | eBay

Hello. I think the switch you are considering is more than adequate, especially for momentary use. Ed.

 

[TaterMay]

Has anyone else had issues with the adjustable SXD drivers? I have had issues with about 4 of them. 2 or 3 have just mysteriously stopped working the same day I completed the build, and one would not move from 4.69 amps, no matter how I turned the pot. I have been heatsinking them to the large copper MX900 heatsink, which has been sufficient for all the other builds, which are all still going strong.

On another note, check this out. This is the highest output NUBM44 I've built yet. I was amazed at about 7.5 watts, and it just kept climbing and climbing. These diodes are just insane.

[URL=http://s356.photobucket.com/user/TaterMay22/media/Mobile%20Uploads/Screenshot_2015-11-02-11-16-30_zpsvize3qls.png.html][/URL]

 

[RedCowboy]

I had trouble getting one to stabilize after adjusting the pot, it's the one that was on the nubm44 that I overheated. My Fault.

I am going to try one of these on my next NUBM build, I like the look of the pot.

6A Adjustable Buck LED Laser Diode Driver for NDB7A75 NDB7K75 NUBM44 445nm | eBay

 

[TaterMay]

I had trouble getting one to stabilize after adjusting the pot, it's the one that was on the nubm44 that I overheated. My Fault.

I am going to try one of these on my next NUBM build, I like the look of the pot.

6A Adjustable Buck LED Laser Diode Driver for NDB7A75 NDB7K75 NUBM44 445nm | eBay

I am always looking to see what I might have done wrong, and have no problem openly admitting fault, regardless of how dumb the mistake was. Lol. But I can't see anything at all that I could have done differently with any of the ones that failed or otherwise acted up.

That does look like a quality driver. But I don't see any way of heatsinking the IC easily?

 

[DTR]

Has anyone else had issues with the adjustable SXD drivers? I have had issues with about 4 of them. 2 or 3 have just mysteriously stopped working the same day I completed the build, and one would not move from 4.69 amps, no matter how I turned the pot. I have been heatsinking them to the large copper MX900 heatsink, which has been sufficient for all the other builds, which are all still going strong.

Not sure about the ones that stopped working but shoot them over to me or Lazeerer and I am sure we can get them replaced as long as they have not had reverse polarity or any obvious damage.

On getting it to go over 4.68A. I am commonly seeing people hitting the limits of their test loads with these. On mine I have to use 14V and the lowest setting on the test load to keep the test loads forward voltage under the voltage from the power supply. I would bet this is the issue. If you are hitting a hard ceiling and the pot can turn more it is probably going up you just cant read it as the unit is falling out of regulation.

I had trouble getting one to stabilize after adjusting the pot, it's the one that was on the nubm44 that I overheated. My Fault.

I am going to try one of these on my next NUBM build, I like the look of the pot.

6A Adjustable Buck LED Laser Diode Driver for NDB7A75 NDB7K75 NUBM44 445nm | eBay

X-Wossee makes some very good drivers with modulation. I am interested to see how these do. Might have to pick a few up myself. I am sure they will work awesome.