Novatac 120P mods, current measurements

Hello all.

Many Novatac emitter swaps happen around here.

However, I don't see drive current data anywhere. (might have missed it?)

So, I thought that I would share some info from my latest 120P mods.

Stock Seoul P4 = 650mA
K2 TFFC = 1000 mA
Cree XPG R4 neutral = 1500mA

It seems that these drivers respond to lower Vf with more current.
The #s hunt around a little bit, with the emitter heating up, but not much.

I gotta say, I'm keeping this new neutral XPG R4 setup.
Something like a 400P now.
:twothumbs

That's EXACTLY the info I was looking for!

What bin are the K2's? I'm thinking I'll use UVOE's, but at 1A, the high runtime really will be 30 minutes!

Thanks,
Kevin

How well does the stock Novatac reflector work with the
XPG emitter ?
Does it need to be shimmed ?

This is very helpful! I believe a Novatac triple might be possible on the stock driver...

kevinm said:

That's EXACTLY the info I was looking for!

What bin are the K2's? I'm thinking I'll use UVOE's, but at 1A, the high runtime really will be 30 minutes!

Thanks,
Kevin

Click to expand...

I believe that the K@ TFFC tested above is the UVOE

tx101 said:

How well does the stock Novatac reflector work with the
XPG emitter ?
Does it need to be shimmed ?

Click to expand...

The beam is nice, well defined hotspot, great spill. The Lux was slightly higher with the K2 TFFC, but the new hotspot is bigger, and the tint so nice.
I used a 2mm thick board from cutter, and just put a .015" plastic insulator between the reflector, and LED board.

foxtrot824 said:

This is very helpful! I believe a Novatac triple might be possible on the stock driver...

Click to expand...

I have no idea how much the driver can handle. But I see no way that it will push 1A+ to 3 leds. You might get a little over 500mA to each, in parallel.

Thanks for the info Moddoo
I have some XPGs on order, looks like I am going to swap
the emitters out in my Novatac as well

Moddoo said:

Hello all.

Many Novatac emitter swaps happen around here.

However, I don't see drive current data anywhere. (might have missed it?)

So, I thought that I would share some info from my latest 120P mods.

Stock Seoul P4 = 650mA
K2 TFFC = 1000 mA
Cree XPG R4 neutral = 1500mA

It seems that these drivers respond to lower Vf with more current.
The #s hunt around a little bit, with the emitter heating up, but not much.

I gotta say, I'm keeping this new neutral XPG R4 setup.
Something like a 400P now.
:twothumbs

Click to expand...

Interesting. These numbers don't quite make sense to me. It seems that the Novatac doesn't have a current driver and the current going to the LED is affected very much by the Vf of the LED. Talking to Henry at HDS, the HDS and Ra lights deliver constant power to the LED and in theory the lower Vf, the more efficient the light (so the less energy needed for any given light level. This doesn't seem to be the case w/ the Novatac. Seems like the lower the Vf, the more current the LED gets (for any given level). I know the Novatacs lack some of the efficiencies of the HDS lights, but the crazy differences in drive current for the various LEDs tested above is very puzzling!

I guess it's time to measure my HDS and Ra...stock LED vs. XP-G.


Edit: When I say, "the lower the Vf, the more efficient the light" I mean a boost converter should work more efficiently stepping up the voltage from 3V to the Vf of the LED. However, depending on the input Vf, drivers might be more (or less) efficient with lower Vf LEDs. Still, I would expect a constant current driver to keep drive levels about the same. Now that I think about it, the HDS and Ra might not be constant current, since Henry emphasized power and not current. Drive levels in these lights must be more affected by LED Vf than a constant current driver.
The madmax lite driver, for example, is a very good driver for those wanting a very efficient "constant power" driver. It is a voltage-regulated driver, but set at "wide open" mode will just deliver max power at near 90% efficiency.
OK, I'm going way off topic here and will stop blabbing.

Moddoo, what batteries are you using on the Novatac to run these tests? A 3.7V li-ion? Bench power supply? 3V lithium primary?

Henry's lights are no doubt constant current, using a variation of PWM for dimming. He explained his circuits in one of his FAQ's when he was selling the HDS EDC's years ago.

Bill

Hey guys, I'm no electrical engineer, though sometimes I wish...

I do not know exactly how the driver works.

I am using an AW IMR 16340, and have not tried the tests with a primary.

My primary setting is pushing about 150mA, and it's plenty of light for most tasks. (about 60 lumens)

I have the XPG on high for extended periods, without any smoke

Moddoo, was this one of the new Novatacs? The pill in mine has a circuit board with a hole in the middle for the LED on the heat sink. It's soldered on at the edges AND glued. Any idea what's going on?

I don't want to break it, but I do want to mod it...

Thanks,
Kevin

How exactly did you measure the current? I have tried for years with my MM and failed miserably, since the switch in the Novatacs is electonic.

kevinm said:

Moddoo, was this one of the new Novatacs? The pill in mine has a circuit board with a hole in the middle for the LED on the heat sink. It's soldered on at the edges AND glued. Any idea what's going on?

I don't want to break it, but I do want to mod it...

Thanks,
Kevin

Click to expand...

My Novatacs are all in the 2xxxx serial # range.
I do not have any experience with the newer models.

Cuso said:

How exactly did you measure the current? I have tried for years with my MM and failed miserably, since the switch in the Novatacs is electonic.

Click to expand...

I soldered the leads directly to the emitter, and driver wire.

This light is truly amazing with this mod.

Thanks. I'll keep it as is until I get really bored.:tinfoil:

Hey Moddo -
I like the mod's [no pun] you have done to the 120P. I have an older one, but one of my concerns was that the low low would not be the same if I swapped in one of those aftermarket LEDs. Is that your experience? I use the .3 [or .8 depending on who you talk to] all the time, and would hate to lose that.

Also, you really like the color temp of that cree neutral R4 compared to the seoul?

Thanks much man!

I have an older 120P with a K2, and the lowest setting shows .13lm according to my lightbox. The manual states .08lm for that level, so mine did go up a bit.