Borislav@87
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No, I get them from here
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FrozenGate by Avery
Blue laser 74W NUBM35 Portabl?
- Thread starter Borislav@87
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I've been told that existotem and techhood are the same seller, just that he has several accounts.
I've been screwed by techhood many times in the past, it's one reason I am reluctant to buy from him anymore.
I've been screwed by techhood many times in the past, it's one reason I am reluctant to buy from him anymore.
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OK, questionable seller, check. But I gotta ask: Did the array come soldered to the PCB like that? Meaning you unsoldered it yourself. Did you observe correct practices to avoid any and all ESD issues when you disconnected it from the PCB?
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No, because the N1ch1a arrays have ESD protection just like their 9mm diodes, it's the little black square on the back right corner of each chips pad...... kinda hard to see in Boiris pic but it's the same as our favorite 9mm ld's
Just like these only the substrate stack is on the right and the esd protection is on the left in this pic > https://endurancelasers.com/wp-content/uploads/2018/08/burned-laser-diode-weak-power.jpg
p.s. While I suppose it's possible I think it's unlikely, I haven't seen any esd issues with dozens of 9mm laser diodes I have harvested from projectors and security blocks and I don't use a ground strap or a pad these days, not when the diodes have the protection, it just hasn't been necessary in my observations.
Just like these only the substrate stack is on the right and the esd protection is on the left in this pic > https://endurancelasers.com/wp-content/uploads/2018/08/burned-laser-diode-weak-power.jpg
p.s. While I suppose it's possible I think it's unlikely, I haven't seen any esd issues with dozens of 9mm laser diodes I have harvested from projectors and security blocks and I don't use a ground strap or a pad these days, not when the diodes have the protection, it just hasn't been necessary in my observations.
Borislav@87
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I don't blame anyone. The seller probably does not know which goods are defective and which are not. There have always been defective goods especially in electronics. That's just my luck. So far, I have assembled about 20 lasers with 9mm diodes and only once I encountered a non-working driver. All diodes still work to this day. Anyway, I wrote to the seller what the case was and sent him the videos. I'm waiting to hear back to see what he has to say. At the moment, the six diodes work without problems at 3.7A. I notice that it heats up quite quickly, probably the damaged diodes also give off a lot of heat. I'm going to redo my case and remove that cooling and put in the big aluminum heatsink with no fans. I will probably buy another NUBM35 and if there are still problems I will give up on this project. I would appreciate the seller making some kind of compensation if I buy another one. I put the small driver yesterday from 600W. This big one is not needed in this case. But the problem is not in the drivers, because I have taken ones that have been tested by people before me and there were no problems.
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Boontwoont
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correct me if I am wrong but I was under the impression that all of "these"* types of blue diode packages were created for use in laser projectors.
*"these" refers to basically any/all of the PCB mounted packages of SMD or Can diode ("direct") arrays from Nichia, Osram, or possibly more explicitly Chinese brands that have flooded Ebay and Aliexpress over the last few years in 10s or 100+ W claimed power (not always clear if its wall plug or optical or "max power when new" or "actual tested" or whatever), some like OP's which come with lenslet arrays, others which have optics in the Cans.
the reason I mention this is that It might be useful to investigate the optics that are built into the projectors themselves to see how they modify the beam to, presumably, create a homogeneous spot prior to passing through some kind of DMD/DLP or LCD filter
Adding a microscope objective after that homogenization might facilitate the goal of increased brightness/intensity in a concentrated spot size.
If my assumption is correct, and these are basically all 2nd hand and surplus projector light sources (the evidence is that basically every variation of these parts *occcasionally* contains the word "projector" from 1 or more sellers listings), then obviously their geometry is designed for exactly the OPPOSITE of high brightness small spot size, as one might want for use in machining or engraving.
Additionally, I was always under the impression that Spectral beam combining required that the emitters have their wavelengths shifted by a few nm at least, and that simply passing them through a microscope objective or prism would not meaninfully increase the brightness
Admittedly about 99.9% of the research papers that deal with SBC fundamentally assume either a Fabry Perot conventional edge emitter (in order to leverage the relatively easily achieved fabrication of high power bars that are arguably among the simplest devices that can be fabricated full stop) or output from a multimode fiber, but my understanding of these blue diodes is that they are electrically pumped VECSELs, although I don't know how that affects the shape of the emitted beam and how that might be different to an edge emitter.
*"these" refers to basically any/all of the PCB mounted packages of SMD or Can diode ("direct") arrays from Nichia, Osram, or possibly more explicitly Chinese brands that have flooded Ebay and Aliexpress over the last few years in 10s or 100+ W claimed power (not always clear if its wall plug or optical or "max power when new" or "actual tested" or whatever), some like OP's which come with lenslet arrays, others which have optics in the Cans.
the reason I mention this is that It might be useful to investigate the optics that are built into the projectors themselves to see how they modify the beam to, presumably, create a homogeneous spot prior to passing through some kind of DMD/DLP or LCD filter
Adding a microscope objective after that homogenization might facilitate the goal of increased brightness/intensity in a concentrated spot size.
If my assumption is correct, and these are basically all 2nd hand and surplus projector light sources (the evidence is that basically every variation of these parts *occcasionally* contains the word "projector" from 1 or more sellers listings), then obviously their geometry is designed for exactly the OPPOSITE of high brightness small spot size, as one might want for use in machining or engraving.
Additionally, I was always under the impression that Spectral beam combining required that the emitters have their wavelengths shifted by a few nm at least, and that simply passing them through a microscope objective or prism would not meaninfully increase the brightness
Admittedly about 99.9% of the research papers that deal with SBC fundamentally assume either a Fabry Perot conventional edge emitter (in order to leverage the relatively easily achieved fabrication of high power bars that are arguably among the simplest devices that can be fabricated full stop) or output from a multimode fiber, but my understanding of these blue diodes is that they are electrically pumped VECSELs, although I don't know how that affects the shape of the emitted beam and how that might be different to an edge emitter.
Borislav@87
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I got a reply from the seller. He offered to pay just $10 for shipping and send me a new array for free. I feel uncomfortable on my end and sent him $50. However, this current one works though with 6 diodes and I will use it. I expect it to be with me in 3 weeks, when I will make some cooling changes that I mentioned above.
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Make sure you have the new unit mounted firmly to your heat sink with a thin layer of compound.
Also when you use your laboratory power supply always start low and carefully turn up your voltage and current limits until you reach your goal, you don't want your voltage turned up past what's needed for your current limit, if you knock a wire loose or have an intermittent connection you don't want your output caps to deliver a big spike.
So if you are turning up your current knob and you get your current set at 3.5A then turn your voltage knob down until you see the current start to go down, then adjust the voltage back up only until you see the 3.5A again, now you have both set.
Same with your dc to dc driver, don't allow the voltage limit to be set any higher than it needs to be once you set your current, back the voltage down so it is also in regulation.
Also when you use your laboratory power supply always start low and carefully turn up your voltage and current limits until you reach your goal, you don't want your voltage turned up past what's needed for your current limit, if you knock a wire loose or have an intermittent connection you don't want your output caps to deliver a big spike.
So if you are turning up your current knob and you get your current set at 3.5A then turn your voltage knob down until you see the current start to go down, then adjust the voltage back up only until you see the 3.5A again, now you have both set.
Same with your dc to dc driver, don't allow the voltage limit to be set any higher than it needs to be once you set your current, back the voltage down so it is also in regulation.
Borislav@87
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Yes yes. I will do everything as you say. First I will test it with the dc unit with a very nice magnification to know that everything works as it should. I will then connect it to the 600W driver.
Borislav@87
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6 diodes at 3.7A are about 35W power. It shines quite brightly.
If the driver was the problem all 14 diodes would die. Today I even ran a 7A current for about 5 seconds and it couldn't kill the diodes. It just happened by mistake. They are currently working without problems again at 3.7A. But it definitely needs better cooling, because for about 1 minute of use, the current cooling heats up a lot.
If the driver was the problem all 14 diodes would die. Today I even ran a 7A current for about 5 seconds and it couldn't kill the diodes. It just happened by mistake. They are currently working without problems again at 3.7A. But it definitely needs better cooling, because for about 1 minute of use, the current cooling heats up a lot.
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Borislav@87
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I would rather knife edge the 7 diode rows from a few nubm35's, but when the price comes down enough I may get a 31 to play with..... safely of course.
You have seen Drakes Styropyro video on his nubm31 haven't you ?
You have seen Drakes Styropyro video on his nubm31 haven't you ?
Borislav@87
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It would be best to have a smooth flat surface and with active cooling you could push to 5A for long duty cycles or even continuous duty.
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Borislav@87
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Yes, I understand that it is best with active cooling. In my case, it will not be used for a long time. I will try these days how it will be with this big aluminum radiator. If it works fine with the current array, I'll mount the new one on it when it arrives. If not I will buy this one from Aliexpress
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You don't have to use active cooling, but your heat-sink or rather your heat-reservior should be flat and smooth so as to make good thermal contact.
If you don't have tools or don't want to go to a shop, you can ask the seller to cut the end off flat and smooth.
Fins increase surface area and allow the sink to cool down faster,
If you don't have tools or don't want to go to a shop, you can ask the seller to cut the end off flat and smooth.
Fins increase surface area and allow the sink to cool down faster,
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