NUBM44 6W+ 450nm Laser Diode

[trussmonkey25]

Okay thanks! the original post is working now

Saw it. Thumbs up

 

[Glutton]

I was just fiddling with my laser and noticed that right after I turn it off a little faint glow still shines from the diode for about 5 seconds until it slowly fades out.

Has anyone else noticed this with the 44?

 

[RedCowboy]

How do you go about testing the voltage sag of a battery when you connect it to a laser?
I have been running my NUB44 with an SXB drawing 8.69 amps off either a single Sanyo NCR18650GA 3500 mAh 10A cell or an LG MJ1 3500 mAh 10A cell. I'm just curious how much these newer cells will compare to a Sony VTC5 in how much their voltage sags when supplying high currents like this.

1 Cell? So your boosting rather than bucking, but either way you just meter your voltage, turn it on and see the sag write it down, let it run for 10 seconds, write it down then compare. Having your meter in parallel testing voltage is no problem, but for current you should use an inductive meter...but never mind that, just meter voltage while running and see what cells stand up best.
As for the dim after glow that sounds like a cap bleeding down.
I don't use the SXB I use the SXD and 2 LG 3000MaH INR cells. It takes more space but should be easier on the batteries and provide more run time.

Trying to save space and not fill up the thread.

ATTENTION BELOW @ Michel pet : You must heat sink that 8 pin chip, just a little chunk of copper can make the difference but it's best to thermal paste them to the host body.

 

[michel pet]

6 watt laser water cooling and driver but i think i bluw up de drive.

 

[lazeerer]

I was just fiddling with my laser and noticed that right after I turn it off a little faint glow still shines from the diode for about 5 seconds until it slowly fades out.

Has anyone else noticed this with the 44?

The Glow is from the Ramp down i have on the driver as well as discharge of the Output Cap Discharging with the On board self discharge. Takes a Few Seconds.

pic

6 watt laser water cooling and driver but i think i bluw up de drive.

Pic

You need to heatsink the driver and not use that heat blocking Temperature Kapton tape. This tape is designed to keep heat away/blocking. So the way you are using it, your keeping the heat in like a blanket!

Heatsink the driver 8 pin chip to your driver heatsink with thermal adhisive and remove the tape.:beer:

 

[Glutton]

Was just playing with my laser and noticed something. I think the high power of this diode may have damaged the AR coating on my G lens. I unfocused the laser to a wide spot and noticed there is a dim bar across the middle of the output and as I continued to focus the laser sure enough that dim bar eventually lined up perfectly with the line of the laser when focused to infinity. I can't see any visible damage on the lens itself and it was clean when installed and is still clean now.

Any volunteers using this diode wanna check if they see anything like I just described?

I have another spare G lenses I am going to try out myself. Going to remove it and make sure it is as clean as possible before installing tho and hopefully I don't see anything similar on the new lens.

 

[michel pet]

can some one tel me wat chip the 8 pins is so i can fix the drive i think de 8 pins is burnd.

 

[Glutton]

can some one tel me wat chip the 8 pins is so i can fix the drive i think de 8 pins is burnd.

Are you asking what it actually is so you can replace it with a new one?

 

[michel pet]

i like to fixs the driver so i need to now wat chip it is type nr name?.

 

[RedCowboy]

Update on my decanned NUBM44 long term test.
I had reported that after a month of heavy use it has finally started to weaken, I was afraid this might be due to the can being removed.

While tearing it down I discovered that although I had it press fitted it that the full copper back half had come loose and there was a gap, actually the back was locked into a copper plate the front unscrewed with focusing, I think I know when it slipped a few days ago because I had trouble getting my lens flare hiderr to grip or so I thought.
It would seem this powerhouse diode was damaged due to user error.
I have snugged it back together with a new back half and it still works but output is roughly 60%

I use a spring on the outside of my 9mm lens barrel and my flare hider is just card stock, I mistakenly thought it was just slipping but upon inspection of the back half threads I can see it unscrewed more than once.
I think even with a press fit I will also run a set screw on everything from now on. The pitiful thing is I usually do
Oh well in the spirit of a fair review I must own this 1, it's my 150 dollar screw up...well un screwed up LOL

Afterthought: If I had used my usual FUJIK mounting type heat sink compound that solidifies or a set screw this embarrassing mistake may not have happened, but attempting to give it the best I used some expensive super copper stuff that comes in tiny syringe type applicators and it stays slicker than owl sh1t. Also I originally had the copper plate at the back of my heat sink stack where it had gripped the back of the copper can, the forward aluminum plates were lubricated with that slick copper colored compound.

 

[Cyparagon]

it's also very important that the compound is an electrical insulator.

Not in most cases.

The test below was much more than a few microns.

You can put a 100kΩ resistor in your electrical socket, and still read mains voltage. But that voltage is insufficient to power anything, because the resistor will limit the current under load.

The flaw in using two pennies, is that no heat is flowing through the junction after the second penny heats up. You'll have vastly different results if you replace that second penny with a large heat sink. Increase the gap to 2mm, and you'll have an almost negligible cooling.

 

[michel pet]

if i want to test the laser no driver but dc power suply wat is the voltage to set de dc power suply to i think 4.6 v max??

 

[RedCowboy]

if i want to test the laser no driver but dc power suply wat is the voltage to set de dc power suply to i think 4.6 v max??

If you have a table top adjustable voltage/current limiting power supply then I usually set my voltage between threshold and 75-80% of the diodes max, then start with the current down or just above threshold and adjust up, but your LD must be heat sinked.

Remember some diodes are very static sensitive such as 405's and if you reach a point where it your diode won't take any more current, yet it's at less than it's specified max, then you will need to increase the voltage, BUT make sure to back down your current until you see it go down any amount so you don't jack your voltage with the current adjustment set too high, you could blow your LD quickly.

By limiting your current the diode will not take overvoltage but if you break the circuit and your voltage is past the diodes limit then it can spike if you say, knock off a wire and put it back on without turning everything down first.

With the NUBM44 you can start at 4.0 volts no problem, it lives around 5.0 normally, start your current low and slowly increase. Diode must be well heat sinked.

You do know you have to wear proper safety glasses, but I have to say it.

Normally with a variable power supply you short your leads to set current, or drive a 1 ohm resistor but just start at zero on the current, limit your voltage between threshold and max for your specific diode. Remember if it stops taking additional current and you are not at your desired target always back your current down until the numbers move before raising your voltage to prevent accidental over current and LD failure.

The advice I gave you was from personal experience and is to the best of my knowledge correct, but what ever you do is at your own risk, remember to always practice safety precautions when working with lasers above 5mw.

 

[michel pet]

i have a adjustable voltage/current limiting power supply.
i good not find the info fore the nub44-6 wat diode max voltage to set the ok voltage.

 

[CDBEAM777]

If you have a table top adjustable voltage/current limiting power supply then I usually set my voltage between threshold and 75-80% of the diodes max, then start with the current down or just above threshold and adjust up, but your LD must be heat sinked.

Remember some diodes are very static sensitive such as 405's and if you reach a point where it your diode won't take any more current, yet it's at less than it's specified max, then you will need to increase the voltage, BUT make sure to back down your current until you see it go down any amount so you don't jack your voltage with the current adjustment set too high, you could blow your LD quickly.

By limiting your current the diode will not take overvoltage but if you break the circuit and your voltage is past the diodes limit then it can spike if you say, knock off a wire and put it back on without turning everything down first.

With the NUBM44 you can start at 4.0 volts no problem, it lives around 5.0 normally, start your current low and slowly increase. Diode must be well heat sinked.

You do know you have to wear proper safety glasses, but I have to say it.

Normally with a variable power supply you short your leads to set current, or drive a 1 ohm resistor but just start at zero on the current, limit your voltage between threshold and max for your specific diode. Remember if it stops taking additional current and you are not at your desired target always back your current down until the numbers move before raising your voltage to prevent accidental over current and LD failure.

The advice I gave you was from personal experience and is to the best of my knowledge correct, but what ever you do is at your own risk, remember to always practice safety precautions when working with lasers above 5mw.

This is a great and practical write-up. I agree with all the points stated. Thank you RC ! :wave:

 

[RedCowboy]

Thanks CDBEAM
I keep pulling out the old 7875 and burning leaves with it and noticing how much tighter the divergence is, then I get out the NUBM44 and even though it's focused line is wider it just obliterates wet green leaves, even in the rain it tears holes in em.
Gotta love that horsepower, I want more:eg: