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NUBM31T 95W 455nm

Light superglue

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Hi guys,

Please stop arguing and let us talk some essential topics:

Brilliant:
You say your 18650 can give 8-10A. How many A did your ammeter show at full power? Do the batteries heat when on? Are they protected? If so, did you test the current where they shut off?
In LiPo batteries I do not think there is any protection built in. Then how to protect them from short circuit?

Giannis:
in this thread
I was testing several cheap drivers (pics in post 12) and found in the last post that the cheapest 250W rated driver can do better than 400W rated driver.
Yes, capacitors heat like crazy, so it would need a proper HS or one can use 2 drivers in parallel, but it seems to work not bad while 400W one shuts off after just a splash. Why is it so?

What about my future build: I would prefer to use 2 drivers for NUBM08. Each can drive 2 rows of NUBM31 from 24V battery and if R24 is removed, then you have TTL on/off switch working from 0.5V.
 



Giannis_TDM

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Hi guys,

Please stop arguing and let us talk some essential topics:

Brilliant:
You say your 18650 can give 8-10A. How many A did your ammeter show at full power? Do the batteries heat when on? Are they protected? If so, did you test the current where they shut off?
In LiPo batteries I do not think there is any protection built in. Then how to protect them from short circuit?

Giannis:
in this thread
I was testing several cheap drivers (pics in post 12) and found in the last post that the cheapest 250W rated driver can do better than 400W rated driver.
Yes, capacitors heat like crazy, so it would need a proper HS or one can use 2 drivers in parallel, but it seems to work not bad while 400W one shuts off after just a splash. Why is it so?

What about my future build: I would prefer to use 2 drivers for NUBM08. Each can drive 2 rows of NUBM31 from 24V battery and if R24 is removed, then you have TTL on/off switch working from 0.5V.
Hi LS, The main problems with such cheap drivers arent cap heat up, Its the current start-up peak. For a more detailed explanation please read my previous posts. And yea I still need to figure out a test load for the ones you sent me, By my calculations ill need ~110 5A rectifier diodes.
 

Light superglue

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Test load: yes, I have big 1000W resistor you saw on pictures.
But what I also want is to check 10A protected 26650 batteries from ali - at what current do they really shut off.

So finally I think to buy this - as one test load for all!

Here tedcs dismantled a NUBM34 and saw a zener diode at each LD. I tought that they are built in to act as spark protection. Or back current protection maybe? Would they not help against start-up peak?
 
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toutan

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Styro used LM338s with a 28v Lipo pack and had the array wired in parallel, 2 of them for each string, Much safer to use the array in parallel because it can handle overcurrent way better of overvoltage in a scenario that a die dies closed.
In series, voltage is required, but in parallel, does it mean that the voltage does not have to be so high?
 

toutan

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The wiring of the NUBM31T seems to make a big difference in power between series and parallel.
As far as I can tell from the video, the way styro is made seems to produce more power.
I've also heard that the current drops when it's in series.
Does this mean that parallel is more likely to produce more power?
If that's the case, is there any point in using LiPo batteries?
 

Giannis_TDM

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In series, voltage is required, but in parallel, does it mean that the voltage does not have to be so high?
Yes In parallel you need about 24v at 4.5-5A per string. Much safer for the array and this way you can drive the array easily without using any shady chiniseum supplies. 2 Lm338s in parallel per string and don't forget load balancing resistors (20-50 milliohms should do the trick).
 

Giannis_TDM

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Apr 27, 2019
Messages
614
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The wiring of the NUBM31T seems to make a big difference in power between series and parallel.
As far as I can tell from the video, the way styro is made seems to produce more power.
I've also heard that the current drops when it's in series.
Does this mean that parallel is more likely to produce more power?
If that's the case, is there any point in using LiPo batteries?
The wiring scheme does not affect output power, Just makes it harder or easier to supply enough power in.
 

toutan

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Yes In parallel you need about 24v at 4.5-5A per string. Much safer for the array and this way you can drive the array easily without using any shady chiniseum supplies. 2 Lm338s in parallel per string and don't forget load balancing resistors (20-50 milliohms should do the trick).
I am not sure how to wire the styro.
It would be best if you had a wiring diagram...
 

BrilliantLasers

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Apr 11, 2019
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Hi guys,

Please stop arguing and let us talk some essential topics:

Brilliant:
You say your 18650 can give 8-10A. How many A did your ammeter show at full power? Do the batteries heat when on? Are they protected? If so, did you test the current where they shut off?
In LiPo batteries I do not think there is any protection built in. Then how to protect them from short circuit?

Giannis:
in this thread
I was testing several cheap drivers (pics in post 12) and found in the last post that the cheapest 250W rated driver can do better than 400W rated driver.
Yes, capacitors heat like crazy, so it would need a proper HS or one can use 2 drivers in parallel, but it seems to work not bad while 400W one shuts off after just a splash. Why is it so?

What about my future build: I would prefer to use 2 drivers for NUBM08. Each can drive 2 rows of NUBM31 from 24V battery and if R24 is removed, then you have TTL on/off switch working from 0.5V.

Yes, the 8 Panasonic 18650s were getting too warm. There was one point where they shut off for a second when they were getting low. I'm not worried about the new lipo batteries I got though, they can handle a ton of amps. I'm running 300 watts out of them now, and they don't even get warm in the slightest, and I always make sure to recharge/balance them before they get too low.

With the 600w driver I have from amazon, I've tested loads of 400 watts, and it was only warm. It has a large heat sync, so the laser is gonna burn out way before the driver will.

If you guys really think this voltage regulator I am using is garbage, why don't you just test it for yourself! It's dirt cheap! Ps, the one in this link has been upgraded and changed since the one I bought. Seems to have more features including a standard DC adapter plug input, which could be really convenient for low amp testing.

Link 600W Regulator: https://www.amazon.ca/gp/product/B08B63RYD6/ref=ppx_yo_dt_b_asin_title_o01_s00?ie=UTF8&psc=1
 
Last edited:

BrilliantLasers

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Yes In parallel you need about 24v at 4.5-5A per string. Much safer for the array and this way you can drive the array easily without using any shady chiniseum supplies. 2 Lm338s in parallel per string and don't forget load balancing resistors (20-50 milliohms should do the trick).
Out of curiosity(not trying to argue again), why is it better to run them in parallel? It's clear each row is already 5 diodes in series.. I thought series was the recommended wiring from Nichia for this device..?

Also, from what I gather, I think @toutan Is looking for a pre built driver. It doesn't sound like he is looking to build one from scratch. Am I correct @toutan ?
 
Last edited:

Giannis_TDM

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Out of curiosity(not trying to argue again), why is it better to run them in parallel? It's clear each row is already 5 diodes in series.. I thought series was the recommended wiring from Nichia for this device..?

Also, from what I gather, I think @toutan Is looking for a pre built driver. It doesn't sound like he is looking to build one from scratch. Am I correct @toutan ?
So I already explained this in my previous posts but here's a TLDR of why parallel is better for a multitude of reasons:
Due to the mentioned extreme output capacitance of the Chinese "drivers" If ANY laser dies in the array fail close suddenly all of the other dies will get overcurrented because the output cap will be charged at a bigger voltage that what they are collectively dropping leading to them all drawing a few dozen more amps in a very short pulse from the output cap than their nominal. As you can imagine quite a devastating scenario leading to the loss of the entire array.

If you have the array in parallel, in case of a failure all strings will effectively take the current that the die that died took leading to a marginal current increase among all of them which is much more survivable than the current loop failing altogether and ending up delivering a short but ultra-high current pulse. Also, it would be safer overall since you decrease the risk of electric shock from very possible to 0(24v vs 92v) and making a reliable lower voltage but higher current supply is much more easy and cost-effective than a low current high voltage one. (Forgot to add, The opamps typically used in said Chinese "drivers" are too slow to correct in time for the first mode of failure(series))
 

RedCowboy

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Lower voltage, less conversion losses if you are up converting such as with 8 x cells.

In the projectors I expect they use 4 supplies on the power board hence the 4 strings, the old 24 diode blocks had 3 rows of 8 and they used 3 power supplies on the power board likely for redundancy should a single diode fail.

---edit---

^ What Giannis said. ^ :)
 

paul1598419

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Yes, the 8 Panasonic 18650s were getting too warm. There was one point where they shut off for a second when they were getting low. I'm not worried about the new lipo batteries I got though, they can handle a ton of amps. I'm running 300 watts out of them now, and they don't even get warm in the slightest, and I always make sure to recharge/balance them before they get too low.

With the 600w driver I have from amazon, I've tested loads of 400 watts, and it was only warm. It has a large heat sync, so the laser is gonna burn out way before the driver will.

If you guys really think this voltage regulator I am using is garbage, why don't you just test it for yourself! It's dirt cheap! Ps, the one in this link has been upgraded and changed since the one I bought. Seems to have more features including a standard DC adapter plug input, which could be really convenient for low amp testing.

Link 600W Regulator: https://www.amazon.ca/gp/product/B08B63RYD6/ref=ppx_yo_dt_b_asin_title_o01_s00?ie=UTF8&psc=1

I have a SMPS used with my 1300 mW 532nm lab laser. I got the thing used a few years ago and it works fine with its cheap Chinese power supply as it did with its original owner.
 

toutan

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Yeah sorry, I was mixed up with MOSFETs and the LM(Linear regulators). I drew this up for you. I wouldn't worry too much about MOSFETs, I am using a 'microwave door' button switch, which can handle 10 amps.

These aren't the exact ones I'm using, but they are all over the place: https://www.amazon.ca/Twidec-Universal-Microwave-Normally-ZW7-15-R/dp/B07NV2NN47/ref=sr_1_2_sspa?crid=3LSZ4SX3S98P3&dchild=1&keywords=microwave+switch+door&qid=1621551919&sprefix=micro,aps,248&sr=8-2-spons&psc=1&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUE2RUZTNzNSQ0ZLWUYmZW5jcnlwdGVkSWQ9QTEwMzU2NTMxSjZYMUlCME9ENlhDJmVuY3J5cHRlZEFkSWQ9QTAwODU4MzMxWU5MMVdaVjkwNVNGJndpZGdldE5hbWU9c3BfYXRmJmFjdGlvbj1jbGlja1JlZGlyZWN0JmRvTm90TG9nQ2xpY2s9dHJ1ZQ==

This is 'series' wiring. With this configuration, the laser wont even turn on until somewhere in the 60 volt range. but the amperage will be nice and low.

View attachment 72744
In this image, I think the plus and minus are reversed.
 

Light superglue

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Hi Brilliant,

I do not think that the driver you use is bad if you can afford to buy another NUBM31 once yours is burnt (like I do). It is just not perfect.
3 years ago I used a similar one with LCD screen to drive the block of NUBM08 here:
Just look at the pictures there!

If you scroll this thread back and read my posts you will find more drivers I have tried or planned to try. In post 140 there are 2 refs. from ali: since then I have tried these with NUBM31 and the 600W was crap but 900W seemed to work well.

BTW what you wrote about powering a NUBM44 from a 18650 directly is nothing special because even at its max charge of 4.2V the current in the LD will not be not more than 2A, what is much less then 4.5A we all do to get maximal burning power...

Toutan: I prefer 2p2s wiring (2 parallel series of 2 rows) what means the driver to output 42V, 6A. And you can find more drivers compatible with this range than with 84V, 3A and even less with 21V, 12A. Just check my threads about combining 2 NUBM36 and you will find some pictures there.
 

BrilliantLasers

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Apr 11, 2019
Messages
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Hi Brilliant,

I do not think that the driver you use is bad if you can afford to buy another NUBM31 once yours is burnt (like I do). It is just not perfect.
3 years ago I used a similar one with LCD screen to drive the block of NUBM08 here:
Just look at the pictures there!

If you scroll this thread back and read my posts you will find more drivers I have tried or planned to try. In post 140 there are 2 refs. from ali: since then I have tried these with NUBM31 and the 600W was crap but 900W seemed to work well.

BTW what you wrote about powering a NUBM44 from a 18650 directly is nothing special because even at its max charge of 4.2V the current in the LD will not be not more than 2A, what is much less then 4.5A we all do to get maximal burning power...

Toutan: I prefer 2p2s wiring (2 parallel series of 2 rows) what means the driver to output 42V, 6A. And you can find more drivers compatible with this range than with 84V, 3A and even less with 21V, 12A. Just check my threads about combining 2 NUBM36 and you will find some pictures there.

Actually when I referred to running NUBM44 from 18650s, it was actually 2 in series(So 8+volts). As I mentioned, of course I would never recommend this, but it was just a fun experiment. The high watt blue diodes are impressively durable. I honestly feel that if my laser gun ever dies, it will probably not be from the power supply, but something something careless on my end, like running it for too long of increment. (My tiny CPU heat sync doesn't do well past 30-40 seconds of straight run time, but as another note a normal size CPU heat sync does perfectly fine).
 




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