Blue Katana, a 70 watt handheld project!

[paul1598419]

If you can turn on each diode separately using the optics you have, you can measure each diode individually and add the results. I am interested in what its actual power will be in the end.

 

[RedCowboy]

Here it is in red print. Read the ad below, look for the red print.

Warning do not use 2S or 3S Lipo packs. Being designed for extremely high instant demant current applications. When connecting to lower current draw loads compared to its potential that transients well past what the input shunt can protect the IC from can be generated. They will damage the driver. Use Li-ion cells if you are looking to power via batteries

https://www.ebay.com/itm/4-5A-SXD-S...047675.m570.l1313.TR0.TRC0.A0.H0.Xnubm44.TRS1

 

[Minamoto Kobayashi]

Thanks Redboy!
So I will switch to the new Blackbuck driver by X-Wossee that seems to support the LiPo packs:

https://www.ebay.com/itm/ACS5500BU-...uck+driver&_from=R40&rt=nc&_trksid=m570.l1313

I hope that the dimensions will fit the driver shelf option for the 20mm back halfs

 

[paul1598419]

This particular Black Buck driver is 16 mm X 10 mm, so you are okay with the shelf on the back of the module.

 

[DTR]

Actually glad this came up as I need to delve deeper into it. The issue is not SXD or Lazeerer driver specific. Every time I have ever heard of a 3S lipo pack is a customer that either says the driver is dead or a lot of times the driver smoked or even made a large pop which with a picture is the the input capacitor blackened or blown to pieces as well as a burn mark on the IC. I have a video I will have to dig up of this happening on a SXD when I intentionally turned the voltage on my supply all the way to max to see what happens. X-drive, SXD, BB3, BB6 does not seem to matter seen this happen on them all. I never really gave much thought as I don't have it pop up too often. Recently decided to look into it and found some tests showing a loading voltage surges for 2S and 3S packs can be huge like 20V for 3S packs due to near zero internal resistance. I don't know if this applies to all Lipo's or just the super high draw packs used mostly to supply instant 20-50A to RC motors. That is about as far as I got an just put that up on the SXD's till I figured out more.

 

[Minamoto Kobayashi]

DTR, so the issue will happen also in the new ACS5500BU 5.5A buck laser diode driver?
I have this LiPo pack:

https://www.ebay.it/itm/RC-Turnigy-...851728?hash=item1a41c92810:g:nfIAAOSwqaJaaCwl

This kind of LiPo pack is a 30C, so 30x5=150A!
So, there is a workaround to add a circuit that may limit the voltage spike? I do not want to fry 9 drivers all together :yabbem:

 

[paul1598419]

No wonder. That pack has a voltage spec of 11.1 volts. At full charge it is likely over 12 volts. I have never had the need to even look at these before now. Glad to know they are not safe to run with laser diode drivers. I'll take you at your word, Jordan. If you have seen this more than once it is not something I would be interested in trying.

 

[DTR]

I can only tell you that I have seen a trend with specifically 3S Lipo packs and the drivers mentioned above. I put that warning up to try to keep anymore issue happen. Now this is just based on a trend I have seen and a couple results of searching for info on these packs. I am happy this was brought up and a discussion which maybe someone with more experience or can offer insight on this trend I have seen. I searched around a lot which was long since most everything you get when searching about these packs with terms like voltage, loading, switching, surge, overshoot, damage, circuit, blown input cap, ect.... brings up 20 pages of how to properly balance and charge these packs an not much about how they do when powering circuits like these. I need to find the pages that I found with some relevant info one was about using these packs to power different electronics and damaging different circuits. Oh here found some interesting reviews on Amazon of all places.
https://www.amazon.com/gp/review/R1Y1NFPP4F6MCI?ref=pf_vv_at_pdctrvw_srp

 

[DTR]

EDIT
Whops double post.

No wonder. That pack has a voltage spec of 11.1 volts. At full charge it is likely over 12 volts. I have never had the need to even look at these before now. Glad to know they are not safe to run with laser diode drivers. I'll take you at your word, Jordan. If you have seen this more than once it is not something I would be interested in trying.

Yea sometimes when I see I am using 11.1V that is also a red flag. Fully charged is 12.6V which is over what I state the max is on the SXD but really it should handle up to 16V and will when run on a bench supply turning it up from zero volts.

Found this.

https://www.eevblog.com/forum/beginners/transient-positive-voltage-spikes-killing-mosfet-drivers/

 

[paul1598419]

Thanks for that link. I didn't realize there was such a large inductance to these battery packs that at time of shutdown the spikes can reach 20 to 30 volts p-p. It makes a lot more sense now that I have seen this.

 

[RedCowboy]

Looks like they run 8 in series. This is the reason 4 are placed one way and the other 4 are rotated 180 degrees, so they can power all 8 in series, LOL

 

[WizardG]

If the issue with the Lipo packs is their low internal resistance then what about adding a low value (0.01-0.1 ohm) resistor in series?

And if the issue is inductive spikes at shutoff then absorb them with a suitable capacitor and/or TVS diode.

I've been using Lipo's in some of my builds for years but always in a 2S configuration and I've never had any problems with drivers or diodes mysteriously dying. I was going to use a 3S pack for the TEC cooled '07 build I'm working on but now I'm going to need to do a little research and play with my oscilloscope a bit hunting for spikes before I put everything together.

 

[DTR]

Yea I just threw 2S in there. One thing seeing is some post saying using cap or TVS that works as intended with the kinds of transients from one source like what we would expect to deal with say 2-3 li-ions in series or a bench power supply whatever may actually have the opposite effect with the very different levels you see out of these packs and the gist was that you have to calibrate it to one or the other which means that either we have multiple versions of the driver or that is handled external between the driver and 3S pack. Actually that reminds me I was looking as some very high end LED drivers over on CPF and it had a drop down for the different power source and remember 3S maybe 2S and 4S not sure if they were listed had have different cap/TVS combo or whatever than the li-ion sources. Will try to find it.

Here are a few things I just dug up again so pretty close to the trail I went down when I decided to write that warning.

https://www.google.com/search?ei=cOpXW57mFdK6zwL574_ABg&q=fast+transient+response+3s+lipo
https://www.eevblog.com/forum/begin...and-linear-regulators-taming-power-up-spikes/
https://www.reddit.com/r/OpenPV/comments/4pqrj8/keep_blowing_the_mosfet/
https://www.rcgroups.com/forums/showthread.php?1883842-Repair-a-fried-minimOSD-(max7456-chip)
https://forum.arduino.cc/index.php?topic=337075.0
https://www.rcgroups.com/forums/showthread.php?2350745-Voltage-regulators
https://www.rcgroups.com/forums/showthread.php?209546-3-cell-li-poly-and-BEC-issues
https://www.rc-monster.com/forum/showthread.php?t=11774
https://diydrones.com/m/blogpost?id=705844:BlogPost:1306337&maxDate=2013-07-01T07:39:19.852Z
https://www.rcgroups.com/forums/sho...nctional-blown-diode-(electronic-expert-nd-d)

 

[Steppenwolf]

Looks like they run 8 in series. This is the reason 4 are placed one way and the other 4 are rotated 180 degrees, so they can power all 8 in series, LOL

I've been following this thread with interest and I don't want to stick my nose in where it doesn't belong but I'm just wondering when they power 8 diodes in series like that I imagine they just use one big driver but how much voltage do they put to the driver and how many amps does something like that draw?

 

[DTR]

I've been following this thread with interest and I don't want to stick my nose in where it doesn't belong but I'm just wondering when they power 8 diodes in series like that I imagine they just use one big driver but how much voltage do they put to the driver and how many amps does something like that draw?

Check this thread. I know they measured how the strands were powered in there. Probably similar with these just higher current.

https://photonlexicon.com/forums/showthread.php/11883-Running-the-XJ-A140-With-Missing-Diodes

Yea I just threw 2S in there. One thing seeing is some post saying using cap or TVS that works as intended with the kinds of transients from one source like what we would expect to deal with say 2-3 li-ions in series or a bench power supply whatever may actually have the opposite effect with the very different levels you see out of these packs and the gist was that you have to calibrate it to one or the other which means that either we have multiple versions of the driver or that is handled external between the driver and 3S pack. Actually that reminds me I was looking as some very high end LED drivers over on CPF and it had a drop down for the different power source and remember 3S maybe 2S and 4S not sure if they were listed had have different cap/TVS combo or whatever than the li-ion sources. Will try to find it.

Here are a few things I just dug up again so pretty close to the trail I went down when I decided to write that warning.

https://www.google.com/search?ei=cOpXW57mFdK6zwL574_ABg&q=fast+transient+response+3s+lipo
https://www.eevblog.com/forum/begin...and-linear-regulators-taming-power-up-spikes/
https://www.reddit.com/r/OpenPV/comments/4pqrj8/keep_blowing_the_mosfet/
https://www.rcgroups.com/forums/showthread.php?1883842-Repair-a-fried-minimOSD-(max7456-chip)
https://forum.arduino.cc/index.php?topic=337075.0
https://www.rcgroups.com/forums/showthread.php?2350745-Voltage-regulators
https://www.rcgroups.com/forums/showthread.php?209546-3-cell-li-poly-and-BEC-issues
https://www.rc-monster.com/forum/showthread.php?t=11774
https://diydrones.com/m/blogpost?id=705844:BlogPost:1306337&maxDate=2013-07-01T07:39:19.852Z
https://www.rcgroups.com/forums/sho...nctional-blown-diode-(electronic-expert-nd-d)

 

[RedCowboy]

I've been following this thread with interest and I don't want to stick my nose in where it doesn't belong but I'm just wondering when they power 8 diodes in series like that I imagine they just use one big driver but how much voltage do they put to the driver and how many amps does something like that draw?

If I was going to drive 9 x nubm44's I would regulate the current not the voltage so I would regulate @ 4.5a and make sure there was 42 volts available although it would likely draw closer to 41v @ 4.5a

Typically I run a nubm44 at 4.5a and it will draw about 4.5v however the factory data projector drives at a lower current that's sustainable with active cooling, it also adjusts for demands and compensates for wear over time, that's why we can push them so hard, there is a lot of headroom built in.

Anyway if you regulate current the diodes will draw the voltage they need, so you want your driver to be able to supply it, also laser diodes don't like spikes or noise so you wouldn't want to use just anything, actually a linear would make sense for 9 x nubm44's in series and would be pretty easy to make.