Setting up first SXD Super X-Drive to NUBM44

[additude]

I'm new and I don't know exactly what to expect. I have an operating SXD Super X-Driver running a NUBM44. I am power inputting the SXD driver with a regulated power supply capable of 0v-30v and 5a. I set the input to the SXD drive at 8.4v and it draws 2.27A from the power supply. Increasing the voltage to 10v-11v-12v causes a slight reduction in current draw. The NUBM44 lights up and appears happy, but at the higher input voltages to the driver, it seems to visually diminish the laser light output of the diode to some degree. 8.4V seems to be epoch best performance.
At the diode, current is at 3.067A @ 4.2V, equating to 1.3964 ohms across the diode and 12.8814W consumed by the diode. However, that is not my output laser light power. Currently, I do not have a tool to measure that right now.
For those that know, does this all sound functionally correct? I'm getting ready to slide all this into a "Hand Held Laser Pointer" that I have been working on and I've had issues with another SXD driver and NUBM44. So any feedback is welcome. Thanks.

 

[RedCowboy]

Most people power the SXD drivers with either 2 x 18650 or 3 x 18650 and set the output current limit with the potentiometer ( if it has one )

Your SXD needs to be heat sinked and your NUBM44 also needs to be in a copper module with a solid back half and in a heat sink.

Many people set up their drivers output with a test load but I use an inductive meter to read dc current between the driver and laser diode

Again your driver and diode need to be heat sinked.

You can buy an SXD driver from DTR pre set to 4.5A

You can attach a small piece of aluminum or copper to the top of the 8 pin chip to heat sink the driver or you can get a host from Lifetime17 with a driver shelf to attach the 8-pin chip.

NEVERMIND THE RED WRITING, THIS IS THE 8 PIN CHIP YOU NEED TO ATTACH A HEAT SINK TO...... DO NOT ATTACH TO THE INDUCTOR ON THE OTHER SIDE.

As long as your NUBM44 is in a solid back half module and in a heat sink you can overdrive it @ 4.5A and your SXD will draw about 3A from 2 x 18650 cells ( into the driver ) and voltage out of the driver into the laser diode will be about 4.5V but the important thing is limiting the current and drawing away the waste heat.

Note: Do not power the driver without a load or laser/led connected.

 

[additude]

Thank you for the info, safety and operational concerns. I have heeded everything that you mention, heatsinked SXD, Properly Heatsinked NUBM44, and my SXD output is 3.067A @ 4.2V, so I am in your output range. Nominal voltage for an 18650 or a 16340 is 3.7V x 2 = 7.4V or x 3 = 11.1V.
So, I set up a second test, this time driving the SXD with 7.4V (As if 2 18650 in series) and the SXD performed even better, providing 3.945A to the NUBM44 @ 4.2V. Almost a full amp more than at a higher 8.4V V+. I was a bit surprised. I got 1A more output for 1V less input and .5A more draw on input. I repeated the test 3 times for verification. That tells me that the SXD optimal performance is at 7.4 V+.

 

[RedCowboy]

I expect you're using a benchtop power supply or a dc to dc converter and you have your current limited too low to provide more than 3.067A @ 7.4V input limit, thus increasing 1V from 7.4 to 8.4 is providing the needed wattage to output 3.945..... basically 4A which is where I expect your driver was set, because I have not seen that phenomenon you described with batteries, only if your batteries voltage sags too low below 6.25V or so will you have an issue, this is why it's best to use good quality IMR or INR high drain cells, but 7.4 or 8.4 or 11.1 or 12V won't make a difference to the SXD driver once you set your current limit.

p.s I like to use 3 x 26650 cells in my nubm44 builds for longer run time between recharging.

 

[Lifetime17]

Most people power the SXD drivers with either 2 x 18650 or 3 x 18650 and set the output current limit with the potentiometer ( if it has one )

Your SXD needs to be heat sinked and your NUBM44 also needs to be in a copper module with a solid back half and in a heat sink.

Many people set up their drivers output with a test load but I use an inductive meter to read dc current between the driver and laser diode

Again your driver and diode need to be heat sinked.

You can buy an SXD driver from DTR pre set to 4.5A

You can attach a small piece of aluminum or copper to the top of the 8 pin chip to heat sink the driver or you can get a host from Lifetime17 with a driver shelf to attach the 8-pin chip.

NEVERMIND THE RED WRITING, THIS IS THE 8 PIN CHIP YOU NEED TO ATTACH A HEAT SINK TO...... DO NOT ATTACH TO THE INDUCTOR ON THE OTHER SIDE.

As long as your NUBM44 is in a solid back half module and in a heat sink you can overdrive it @ 4.5A and your SXD will draw about 3A from 2 x 18650 cells ( into the driver ) and voltage out of the driver into the laser diode will be about 4.5V but the important thing is limiting the current and drawing away the waste heat.

Note: Do not power the driver without a load or laser/led connected.

 

[additude]

I expect you're using a benchtop power supply or a dc to dc converter and you have your current limited too low to provide more than 3.067A @ 7.4V input limit, thus increasing 1V from 7.4 to 8.4 is providing the needed wattage to output 3.945..... basically 4A which is where I expect your driver was set, because I have not seen that phenomenon you described with batteries, only if your batteries voltage sags too low below 6.25V or so will you have an issue, this is why it's best to use good quality IMR or INR high drain cells, but 7.4 or 8.4 or 11.1 or 12V won't make a difference to the SXD driver once you set your current limit.

p.s I like to use 3 x 26650 cells in my nubm44 builds for longer run time between recharging.

Hello.
Yes, I am currently using a benchtop current regulated supply, which I have opened up the current to max (5A unrestricted no limit), and I only adjust the P/S voltage input to the SXD to 7.4V allowing the SXD driver to handle the output requirements.
I have swapped in a new NUBM44 using this SXD and here are my results:
At 7.4V input to SXD, output to the NUBM44 is 4.3V @ 3.2A
At 10.5V input to the SXD, output to the NUBM4 is 4.3V @ 3.8A (Fluctuating .1A - .2A) and the SXD shuts off in 3 to 4 seconds. I suspect to over-temp, even though it is heatsinked and doesn't really feel overly warm to the touch. @ 7.4V input to the SXD it will run the Laser for as long as I will let it go, like maybe a minute to a minute and a half.
So, I have since ordered and swapped in a new SXD with the original NUBM44 and I already have that setup mounted and functioning in a pointer with two 16340's and that setup is working well in that scenario. I think I just have a weak SXD.

 

[RedCowboy]

You put your heat sink on the SXD's inductor, that can interfere with it's function.
You need to put the heat sink on the 8 pin chip, it's on the opposite side.

2 x 16340 cells may sag too low under load and prevent you from getting full output.
However you can usually use 18350 in the same host.
1st and 2nd number are the diameter and the 3rd, 4th and 5th are the length.
16mm wide and 34.0mm long ( 16340 )
18mm wide and 35.0mm long ( 18350 )

Use a high drain cell.
For instance you want the red or purple cells, not the green cells in the listings below because even though the green cells have the highest mAh they have the lowest sustained draw current, this is due to slight differences in the chemical formulations and is typical.

Red = 10A, Purple = 9A, Green = 3A

2x Vapcell M11 9A 1100mAh Rechargeable Flat Top High Drain 18350 Battery & Case | eBay

Genuine Vapcell M11 18350 1100mAh Batteries. Free Vapcell Storage Case x1. Never leave charging batteries unattended. Use of this item at your own risk! Never use a lot of strength on battery installation.

www.ebay.com

2 x VC INR 18350 LITHIUM RECHARGEABLE BATTERY INR 1100mAh 3.7v 9 amp FLAT TOP | eBay

Find many great new & used options and get the best deals for 2 x VC INR 18350 LITHIUM RECHARGEABLE BATTERY INR 1100mAh 3.7v 9 amp FLAT TOP at the best online prices at eBay! Free shipping for many products!

www.ebay.com

2x Green V.C. F14 3A 1400mAh Rechargeable Button Top 3.7v 18350 Battery & Case | eBay

Find many great new & used options and get the best deals for 2x Green V.C. F14 3A 1400mAh Rechargeable Button Top 3.7v 18350 Battery & Case at the best online prices at eBay! Free shipping for many products!

www.ebay.com

 

[additude]

Great Info. Thanks!!