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NUBM31T 95W 455nm

likevvii

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Here is the link to the OSRAM chip, they also had some used Nichia chips too, so I picked one up from them.
(I apologize i cant post links yet, I need 20 posts.)

dglanji.en.alibaba.com/product/62404903348-218283641/High_Power_450nm_50W_Blue_Laser_Bank_For_Illumination_Source.html?spm=a2700.icbuShop.41413.12.2a01651f3E3B96

Got both for 300USD :D
Because of COVID-19 most Chinese companies are struggling for cash flow so you can take advantage of this time to bargain.

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I got a plano convex lens, 50mm dia, 200mm FL. I hope the combination of modifying the height of the front multi lens + this PCX lens can get me some good spot diameters.

___

I am currently looking for a driver that is not 500USD to officially drive this with current control. PLEASE HELP. I can modify/build/test drivers if they fall in the 30V/10A requirements of these arrays. I wish to be able to change the current output on the go like those 500USD untis do.
 



RedCowboy

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Ah Thanks, very cool, was having trouble finding it.

Are the beams as well focused/collimated as the Nubm31 ?

 

likevvii

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It is arriving in a few days. I will be able to test them both. I wonder if I will need OD7/8 goggles when I start playing with these. I currently only have OD6.
 

RedCowboy

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OD 2 is 1/100 so OD 6 means you get 1/1,000,000 IINM so you should be well protected from diffuse reflections, that said the face seal goggles are never a bad idea, but as long as you are careful a good quality OD 6 should provide adequate protection.
 

farbe2

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I have purchased a module from Techood

My findings so far:

Seems like the built in multi lens is out of focus.
Also the beams don't seem to line up. The top row seems to be slightly tilted. This is bad news for me because focusing this array seems impossible, spot size is huge.

I was hoping to upgrade my lasercutter with one of these. My CO2 tube seems dead and doesn't cut acrylic very well anymore.
I don't have the balls to loosen the glued on lens yet, has somebody any experience in doing so?
Anyone a idea to focus this beast?

I am currently looking for a driver that is not 500USD to officially drive this with current control. PLEASE HELP. I can modify/build/test drivers if they fall in the 30V/10A requirements of these arrays. I wish to be able to change the current output on the go like those 500USD untis do.
I have purchased a 6ch driver from Live Lasersystems i payed 300€
Looks good so far, i haven't used the integrated tec driver but all 6 output channels.
Efficiency seems high if tuned correctly and modulation seems to be fast like advertised but i haven't measured it.

I hooked it up like the company told me:
2 rows in series and the other 2 directly to the channels.
Power usage is 300W 48V input with the array at 3.5A.
Datasheet: downloads.live-lasersystems.at/colordrive/V1.2_manual_Colordrive6_web.pdf
 
Last edited:

likevvii

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I have purchased a 6ch driver from Live Lasersystems i payed 300€
Looks good so far, i haven't used the integrated tec driver but all 6 output channels.
Efficiency seems high if tuned correctly and modulation seems to be fast like advertised but i haven't measured it.

I hooked it up like the company told me:
2 rows in series and the other 2 directly to the channels.
Power usage is 300W 48V input with the array at 3.5A.
Datasheet: downloads.live-lasersystems.at/colordrive/V1.2_manual_Colordrive6_web.pdf
Wow, awesome!!!
May I know how did you find this driver? I tried to Google the 6ch module you have and it is not even on their website. It is quite shocking how many things exsist without public knowledge. I'll will be in contact with them. Do you know of any other places I can look for other types of drivers?

When I get my arrays, I will definitely cut free the lens and let you know how it goes. The documentation of the 6ch driver is quite hard to understand for me as of now due to my lack of knowledge.

Do you know if it can externally control the current? Like an input 0-5V = 0-3.5A output like the other drivers I posted?

You mentioned about modulation, does that mean pulsing? I am not too familiar with pulsing; do you pulse lasers in the laser cutting industry? What type of benefits do you get from pulsing compared to continuous?

Thanks,
 

farbe2

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Hello,

Wow, awesome!!!
May I know how did you find this driver? I tried to Google the 6ch module you have and it is not even on their website. It is quite shocking how many things exsist without public knowledge. I'll will be in contact with them. Do you know of any other places I can look for other types of drivers?
I have purchased other stuff from them before, its my goto for quality optics and drivers.
Other company may be swisslas.ch , they also don't have all the components on the site, but i don't know if they have something.

When I get my arrays, I will definitely cut free the lens and let you know how it goes.
Thats NICE! hope you don't kill your module, i am very scared to do so.

Do you know if it can externally control the current? Like an input 0-5V = 0-3.5A output like the other drivers I posted?
Yes you can, its a classic laser driver with 0-5v modulation input. For now i connected a powersupply to control the output power, eventually this will be changed to the original laser cutter power control.

As i understand is it possible to input 3 different modulation signals for RGB, as its normal used for RGB laser projectors.
But you can connect all 3x2 channels together to get 3x 5A current for your laser diodes with up to 48V for the diodes.

Each row of 5 are around 22V, so 2 rows are connected in series for 44V which the driver can handle.
So only 2/3 of the driver are really needed for the lasermodule.
2x 10 diodes in series (2x 2 rows in series connected to 2 outputs of the driver).
I have used 2 rows in series and connected the remaining rows to the 2 remaining driver channels, this gives me the possibility to control the current independently, i don't really need it but its nice to have.

The modulation input seems fast wich should be good for graphic cutting e.g. raster and different intensity engraving.
The curves at the data sheet indicate that there is no overshoot in current if you turn the current up, so the diodes should hold up to overdriving them.

This thing also has dcdc conversion integrated, this means it doesn't "burn" the voltage that's not needed (like styropyros driver) so it has a much higher efficiency. This is what sold me to the driver, it doesn't need much cooling, also the protection features are very good.
 

likevvii

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Thanks for the explaination.
So the output control is only duty cycle modulation and not true current control?
My application requires continuous output with varrying current. (Laser excited phosphor)
 

farbe2

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Hello,

No its real analog current control with the modulation input. But its also possible to make pwm/fast analog control.

If you set the driver to deliver 1A than it will deliver 0.5A if you supply the driver with 2.5V modulation.
It also has standby power cutoff, this is commonly used to set a threshold current and voltage.

So you can do something like this:

Modulation Input VoltageOutput current example with thesholdwithout threshold
0V0A0A
0.5V (adjustable threshold voltage)2A (adjustable threshold current)0.5A
2.5V3.5A2.5A
5V5A5A

Most laser drivers can do this type of modulation curve. So you can set a threshold current to which the driver will go if the threshold modulation voltage is reached. This makes the diodes better to control, otherwise you have no laser action if the current is not high enough.
 

likevvii

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Ohh ok. That is perfect.
I want to use a potentiometer to adjust current. It was mentioned the signal from a pot is noisy and may cause problems. Do you know a good way to control current externally?
Like a flashlight/searchlight it needs to be easily adjusted without looking.
 

farbe2

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Hello,

There should be no problem with a simple pot.
It might noisy especially if its worn, BUT: This will only introduce spikes/lows in the modulation signal, the driver is tuned to for example 3.5A so the maximum it will output is 3.5A.
If you pot is noisy than it can happen that the pot will give very short periods of higher/lower resistance. If you connect the pot the classic voltage divider way (one lag to GND other leg to 5V, viper as output) the viper becomes the modulation signal voltage. If the pot has "problems" the voltage at the viper will go up or down. The driver follows the modulation signal e.g. your pot and will output spikes of current up to 3,5A but that will not cause any problems because the diodes can handle that and our eyes are to slow to catch the us or ns higher light output.
You can also use a capacitor to "smooth" the pot viper signal e.g. connect between viper and GND. Now the noise will get smooth out.
If you use a good quality pot than this can be ignored.

You could also use an arduino to read 2 push buttons to have a up and down button or something, the possibilities are endless.
 

likevvii

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It is very clear to me now, thanks!
If I'm feeling fancy, I guess I could freelance a simple Arduino program with LCD display!

A few additional questions if you know anything related to this:

Are lasers more efficient when pulsed? 50W 100%duty vs 100W 50% duty

Do you plan to use the TEC? I wonder how much size, power, and output heat will need to be sufficient for the 200W at Max power.

Could you show a picture of the multi beam profile?
It seems the most important thing is how the diodes are mounted to the chip. If they are all parallel or aimed at the same point, then it should be easily focused if the lens is also dimensionally correct.

It would be unfortunate if the alignment of the array comes down to luck.
 

Light superglue

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Hi Farbe2,

I would also like to see a picture of the multi beam profile.
Could you please make a picture of the spot from this array on the wall through OD6 googles at let us say 1 and 5m distance passing low current through each row. 0.3-0.5A would be enough I think. Like I did in my studies of NUBM08/44 arrays earlier here on LPF.

TEC for 200W CW? Probably does not exist. I would use water cooling.
 

farbe2

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Hello,

Are lasers more efficient when pulsed? 50W 100%duty vs 100W 50% duty
Do you plan to use the TEC? I wonder how much size, power, and output heat will need to be sufficient for the 200W at Max power.
I am no expert, but I can make an educated guess:
I believe its inefficient to pulse the diodes 50/50% vs driving at 1/2 current because:
The formula for power is: P= I² x R
So for example the connections at the bond wires and external wiring = 0.2R (its just an example)

If you drive the array with 1A you will get 1² x 0.2R =0.2W
If you drive the array with 2A you will get 2² x 0.2 = 0.8W now divide that by 2 for half the time active = 0.4W

You can easily see that increased current will get the efficiency down fast.

Somebody may say: "but what about the temperature".
This is a rabbit hole, please be careful ;)

If the temperature inside the laser diode crystal rises the efficiency drops significantly.
Theory: if you drive the diode 1/2 of the time the crystal has time to "cool" and runs cooler so more efficiency.

My guess:
The laser crystal is really really small inside the diode. So even if it has time to cool between pulses, when the pulse starts the crystal will get hot really fast because the mass of the crystal isn't big so it can not absorb a significant amount of energy before heating up.
Combined with the fact that the efficiency drops with increased current -> look at the chart inside the data sheet for the PL_TB450B diode.
Link from DTR: docs.google.com/file/d/0B_6-KC5wFXIJTXBfTmJjY1lMamM/edit

Also think about the stress that the crystal experiences:
If you look closely at the data sheet mentions 15k/w thermal resistance between case and crystal.
This means the crystal will get 15K warmer if you pass 1W through it.
Quick calculation to calculate the temperature if it runs full power:
Let us calculate with the values that dtr shows, 1.5A to not "overdrive" it, lets assume its cooled with a tec to 20°C
DTRs pictures show it needs 5V for 1.5A so thermal power would be: P=(I x V)-Po
Po is optical power, this needs to be subtracted to get thermal power inside the crystal.
(1.5A x 5V) - 1.8W = 5.7W
To calculate the temperature we can do:
(5.7W x 15K/W) + 20°C = 105,5°C for the crystal.

To get everything together the same calculation for 1/2 power (values also from DTRs pictures):
Crystal thermal power:
(0.8A x 4.6V) - 0.9W = 2.8W (you can even see that the efficiency is higher steady state without pulsing)
Crystal temperature:
(2.8W x 15K/W) + 20°C = 62°C

So if you pulse the diode the crystal will experience rapid heating from 20°C to 105°C, but in reality its worse because the thermal resistance from case to mount is ignored.
If you drive the diode 1/2 current the temperature will drop, this is good because the diode will be more efficient.

Combine the two and you get reduced efficiency if you pulse the diodes.
More current equals to more resistive losses inside the diode, wiring and driver
More current also equals to higher temperatures for the crystal equals to higher losses and more stress: shorter lifetime.

Again, I am no expert, but for me at least it makes sense to drive the diodes with reduced current if you want less power.

I would also like to see a picture of the multi beam profile.
Could you please make a picture of the spot from this array on the wall through OD6 googles at let us say 1 and 5m distance passing low current through each row. 0.3-0.5A would be enough I think. Like I did in my studies of NUBM08/44 arrays earlier here on LPF.
I will make a picture for all of you, but I can currently not leave my home because of the virus, if I get to my workshop I will make pictures.
Would be nice to know if its luck or if all the modules are the same, I only have one so I cannot do a comparison.

Light superglue /Likevvii said:
Using a TEC?
I currently don't use a TEC, it can be done but I don't know if it is really the smartest thing to do.
We need something that's capable of pumping more than 200W so my idea would be to use a TEC1-24116.
It could pump hold the module at 20°C if we can get the hot side to around 50°C but it will need 420W to accomplish this.
This means we go from 300W overall power to 720W, this will drop the efficiency of the overall design to very low values without adding much benefit.
If we can thrust the datasheets for the NUBM31 module, the module has no problems with running at 70°C case temperature.
So if we use a TEC then we need to get a much bigger heatsink.
Quick calculation:

With TEC 720W @ 50°C with 35°C ambient
50°C-35°C = 15k headroom for the heatsink
15K / 720W = 0,02K/W Heatsink

Without TEC 200W @ 70°C with 35°C ambient
70°C - 35°C = 35K headroom
35k / 200W = 0.175 K/W Heatsink

As everybody can see the heatsink needs to be roughly 10 times as huge if we use a TEC.
Water-cooling may be needed for a TEC.
Without tec it doesn't look bad, 0.175K/W is not such a big heatsink. Spread of the heat across the heatsink should also be ok, maybe we need heat pipes.
I did mount it on a heatsink that's forced air cooled and has around 0.15k/W but I didn't power the module long enough to see significant temperature increase.

If you have a remote phosphor application it might be needed because the wavelength shift that occurs if the module reaches higher temperatures. But I don't have knowledge at this topic.


Sorry for my long post, please respect that I am not a native englisch speaker, but I think I did a good job of explaining.
Have a nice evening.
 

likevvii

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Once again, thanks for the explaination.

It makes sense why pulsing would be less efficient. Even TEC cooling recommends to not use PWM for higher efficiency. Lasers are quite new to me, so I thought they would go by a different rule.

Regarding a TEC, I asked because the driver included a TEC controller. Using a tech for anything above 50W doesn't make sense. However, this is a 900W driver so idk what to think. Maybe they added TEC controller because the extra unused channels can be used for TEC?

I will most likely use high performance air cooled CPU cooler for cooling application. I do not care about diode life due to heating because the useage is very low.
 

likevvii

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Alright guys,
Here it is. Nichia VS Osram. (Nichia NUBM31T 95W VS Osram PLPM4 450 - 60W)


This is my first time doing a beam test. I did what I wanted to do.

Driver used: MDP-XP w/ 4 modules

Note: Nichia = made in Japan, Osram = made in China.
 

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