Welcome to Laser Pointer Forums - discuss green laser pointers, blue laser pointers, and all types of lasers

LPF Donation via Stripe | LPF Donation - Other Methods

Links below open in new window

ArcticMyst Security by Avery

Does this sound right to you?

Joined
Feb 10, 2013
Messages
2,125
Points
63
I've got a 1.9A X-Boost that is adjustable. I built a 3A test load. I'm not sure what values to expect when hooking the meter up right to the load w/ just a 3.9 V (charge at the moment).

When I hook up my driver, and select the diode for my build, I get some interesting readings. The DMM shows a mV signal at ~1750mV, but quickly drops down to ~1600mV and then shows a slow drop in the reading. I'm assuming this is due to excess heat on the driver and the battery charge dipping as the driver pulls it's load.

I guess what I am asking is whether what I am seeing in the slow current loss is normal.

Secondly, I'd love to hear from other X-Boost owners. I've heatsinked the $h!t out of this thing, but it still gets scorching hot! Looks like I need to add more copper...

Thanks all!
 





clif

0
Joined
Oct 9, 2010
Messages
268
Points
0
Boost drivers run hot by their nature, especially one that does 1.9amps.

One reason you get that drop could be the battery is experiencing pretty good voltage sag or drop under the load (assuming your battery isn't up to the task), a boost driver will draw more current from the battery than it provides the laser diode. Even MORE so when not fully charged @ 3.9V vs. 4.2V.

You will want to use a high quality battery for this driver, anything XXXFire won't cut it, those have shown me from my experience with them they can't handle high current draws. The 18650 xxxfires I used to buy could handle maaaybe 2-2.5 amps if they were the "better" ones if there is such a thing. The boost driver set to 1.9amps at only 3.9Vin is probably drawing I'll bet over 3 amps from the battery. My numbers aren't exact but basically you get the idea. The lower the input voltage the more current draw from the battery you will see.

The test load components also heat up, and at some point your reading will likely change because of that also even if using a power supply.


How many diodes are in the test load by the way?
 
Last edited:
Joined
Feb 10, 2013
Messages
2,125
Points
63
Thanks Clif. I'm using Panasonic 18650s @ 3100 and 3400 mAh. I am not surprised by the heat generated so much as by the inadequacy of all of the copper I've stuck to the driver. Looks like I'll be doing more machining when my host gets back from JayRob.

I don't remember why (Vf, charge, etc) exactly that I'd not read 1.9mV on my meter. When dialing it in. I just locked it down at the highest initial reading I got when adjusting the output. I was just curious about the slow but continual drop in current as I tested. It makes sense when factoring all of the variables. I was just looking for some input.

Thanks again for your advice as well as all the goodies!
 

clif

0
Joined
Oct 9, 2010
Messages
268
Points
0
Is it an auto ranging type meter?

The slow current dropping I can maybe see, not sure on the initial big drop...

Your batteries also sound adequate to me btw.
 

clif

0
Joined
Oct 9, 2010
Messages
268
Points
0
If you can, set it to just measure volts or millivolts. Sometimes those autorange ones will cause reading errors. At least, I've seen that when taking other measurements outside of lasers.
 
Last edited:
Joined
Jan 8, 2009
Messages
3,145
Points
83
You prolly should have not put the copper on top of the inductor coil either... if you NOT have glued it on then take it off if you did then LEAVE it on.

Just to be sure you are using the DMM setting over the resistor testing to V not Amps?
 
Joined
Feb 10, 2013
Messages
2,125
Points
63
You prolly should have not put the copper on top of the inductor coil either... if you NOT have glued it on then take it off if you did then LEAVE it on.

Just to be sure you are using the DMM setting over the resistor testing to V not Amps?

Unfortunately, I do not know which component is the inductor coil. Why would I not want to sink that?

I was measuring the voltage across the resistor, and not measuring current directly.
 

clif

0
Joined
Oct 9, 2010
Messages
268
Points
0
Unfortunately, I do not know which component is the inductor coil. Why would I not want to sink that?

I was measuring the voltage across the resistor, and not measuring current directly.

I didn't even think about that one - it may mess with the inductor coil's function though right?

The coil is the square part labeled C222
 
Last edited:
Joined
Jan 8, 2009
Messages
3,145
Points
83
Unfortunately, I do not know which component is the inductor coil. Why would I not want to sink that?

I was measuring the voltage across the resistor, and not measuring current directly.

Ok cool, you got the testing down good job the inductor on that driver is right in the attachment pic don't take it off if it's glued it's not really that big o deal:beer:
 

Attachments

  • 4zPHh9N.jpg
    4zPHh9N.jpg
    75 KB · Views: 72
Joined
Feb 10, 2013
Messages
2,125
Points
63
Ok, well, I did heatsink it. I used a sliver of hand-hammered copper, glued w/ AS adhesive, so that the height would match the other components to fit the beefy HS. Here's some pics.
G2NuzUT.jpg

4zPHh9N.jpg

KZ2JLF7.jpg


It looks like I am going to have to remove the big HS and re-machine something beefier. Is there a safe solvent that I can use to remove the inductor coil HS? I might as well remove it if I can while I have it exposed.
 
Joined
Apr 2, 2009
Messages
10,662
Points
113
+3 to clif & jander- nice job of helping out another member--

great pics always make helping easier..
+3 to the OP..
 

clif

0
Joined
Oct 9, 2010
Messages
268
Points
0
Thanks Hak! Yea I like to pop in every now and then :shhh:
 
Joined
Feb 10, 2013
Messages
2,125
Points
63
Big thanks to all! I appreciate the feedback and advice. +3's all around, as the system allows.
 
Joined
Sep 12, 2007
Messages
9,399
Points
113
Copper on inductors is bad. The inductor will cause eddy currents in the copper, heating it up, and the ferrite core will saturate sooner, leading to even more heat and poorer regulation.
 
Joined
Feb 10, 2013
Messages
2,125
Points
63
I am very happy with the purchase and Clif's support. I wish there were more documentation on this X-Boost drive. Though, I doubt I would have read in most forms of documentation would have had that kind of information. That's some pretty esoteric stuff that was beyond my limited electronic skills. I've read much about any number of drivers, and don't know that I've ever read that heatsinking any particular components with copper would cause issues other than not keeping your leads insulated.

Thanks Cyparagon for this bit of info. +1 for the concise explanation. :beer:
 




Top