Mini Mag thrower finished(beam shots)

[LED4LYF]

Finally finished my red min mag thrower, Won't compare to some of the big throwers but I think it turned out pretty good

Parts list:

Red AA mini mag
xp-g r5 on 10mm board-(I know it is not the best led for a thrower, but it was an extra)
bb nexgen 1000ma driver board
AW 14500 protected cell
acrylic ball for lense
terra lux tail switch


Here is my heatsink/drop in pill/dummy battery spacer so it runs on one 14500 cell.

Here in the bb nexgen driver press fit in back

Shot of pill and mini mag side by side

Now for beamshots-All shots are from about 15meters

First shot ISO 80

ISO 80 zoomed

Next is ISO 800

ISO 800 zoomed

 

[SmurfTacular]

:twothumbs

Nice mod dude. Turned out clean.

Very innovative using the extra batter space as a heatsink.

good work :thumbsup:

 

[Justin Case]

Very nice.

Be careful to avoid frying the light. The 1xLi-ion voltage is probably greater than the XP-G's Vf, so you probably aren't running in boost mode.

 

[LED4LYF]

I guess the foward voltage of my LED is around 3.3v and my bat is 4.2v. I did not know that would be a problem. I thought on this driver you just had to be in the given voltage range and it did not matter what the Vf was?:thinking: That is the last thing I want:poof:. What does boost mode do?

 

[Justin Case]

From the Shoppe link for the BBNG1000: "Vin overdrive voltage: Vout+0.7V"

Boost converter

 

[jason 77]

I guess the foward voltage of my LED is around 3.3v and my bat is 4.2v. I did not know that would be a problem. I thought on this driver you just had to be in the given voltage range and it did not matter what the Vf was?:thinking: That is the last thing I want:poof:. What does boost mode do?

I thought so as well?

"Note1: Safe mode is ~1.5A input current. If output doesn't go into full regulation it falls back to safe mode. For a Nexgen 750mA or Nexgen 1A, this critical starting voltage is ~3.4V. Input voltages above this will start the regulator into full constant current regulation and it will regulate down to ~2V input. A Nexgen 500mA will almost always start in full regulation mode."

I used the same driver in my mini mag mod as well, wonder if I run the risk of having my LED go :poof: ??

Nice minimag mod by the way!

 

[Justin Case]

You need to ask yourself some questions:

- What happens when Vin > Vf when using a boost driver?
- What LED does The Shoppe's Note1 refer to?

 

[Blue72]

very nice!!!!!

Have you considered using the half an acrylic ball (aspheric lens) it fits nicely in the mini maglite anti-roll lens holder and prevents damage to the led from the acrylic ball. I also notice it throws slightly better as well.

 

[LED4LYF]

Ok I think I get it now. So since my Vf of led is around 3.3v and V overdrive is .7v, safe would be 4.0v. Since my freshly charged 4.2v li-ion is higher i might run the risk of burning up the board or LED. I have run it for 20min strait and it only gets slightly warm so I guess it will be ok.:shrug:

 

[LED4LYF]

I do have the 1/2 acrylic as well. I think you are right it does throw better I just liked the way the ball looked in the light. Will try to post some somparison shots tonight.

 

[Justin Case]

Ok I think I get it now. So since my Vf of led is around 3.3v and V overdrive is .7v, safe would be 4.0v. Since my freshly charged 4.2v li-ion is higher i might run the risk of burning up the board or LED. I have run it for 20min strait and it only gets slightly warm so I guess it will be ok.:shrug:

I don't think it's quite that simple. When a boost driver goes direct drive because Vin > Vf, Vin+ goes through the inductor, Schottky diode, and current sense resistor(s), and finally to Vout+.

If you overdrive your LED by pumping it with V~4V, what is your drive current? If you get an XP-G drive current of 1A at 3.3V, I would suspect that your drive current can be quite high at 4V -- maybe 3A-4A.

Do you think your LED and BBNG components can survive that? I think what is saving you is that the relatively small 14500 cell sags quickly under load, and the LED and BBNG actually see much lower voltage. If you tried to drive this same setup with an IMR26500 (hypothetically speaking, since obviously a AA Mini Mag can't fit a 26500 cell), I bet you'd instantly cook something.

I probably would have selected a GD1000 for your particular application.

 

[LukeA]

I think what is saving you is that the relatively small 14500 cell sags quickly under load, and the LED and BBNG actually see much lower voltage.

Then all this fuss may be for nought, pending tailcap current readings, of course.

 

[Justin Case]

The "fuss may be for naught"? Make some change that "improves" parasitic resistance and all bets are off. It takes only a couple of tenths of volts increase in voltage to the LED to increase the drive current from 1A to 2.5A and higher. You ignore potential risks at your own peril.

 

[LED4LYF]

All right I will take some tail readings tonight and post what I get Thanks for the info.

 

[mrartillery]

Nice! :thumbsup:

 

[LED4LYF]

I took some tail readings and I was getting 1.2A on a pretty much fresh battery.