QIII Direct Drive - light, power, heat - pick all three

I like to think of this mod as a "Poor Man's Orb Raw". (It's either that or some version of "Death Wish").

Having a nice Lux III UWAJ star from 4sevens and knowing how easy the Nuwai QIII is to mod. I decided to disble the QIII's converter circuit and see what would happen if I connected the star directly to an unprotected 800mA RCR123 cell:


I also (correctly) figured that my two stage would be used more at the low setting than the current sucking high setting, so I bumped up the low setting with a second 10 ohm resistor:


The results range from incredible brightness to "I won't be surprised if this poor, unprotected cell blows up in my face." Here are the current / voltage / power readings I obtained:

2.2A Vf=3.5V 7.7W
1.9A Vf=3.4V 6.4W
1.6A Vf=3.3V 5.3W
1.3A Vf=3.2V 4.2W
140mA Vf=2.97V .415W (5 ohm in the two stage switch)

I'm more concerned about the unprotected cell failing (exploding?) than the emitter failing. The retaining ring is quite tight against the star, and there is thermal compound on the star and the aluminum heat sink ring of the QIII. The light warms up quickly at full power, indicating good thermal transfer.

Here's a beam shot. The QIII is pulling 1.9A (6.4W) and the Orb Raw cell is hot off the charger:


You can see how intense the beam is from the QIII. At 1.3A (4.2W), the QIII appears equal to the Orb Raw. Unaccounted for is the QIII's reflector - it is a heavy stiple vs. the smooth of the Orb. I wish there was a smooth reflector for the QIII as I am pretty sure that would result in a 15 to 20% gain in illumination.

Note the Vf of the UWAJ at 140ma, 2.97V, effectively making it a UWAG at that level:


Next on my QIII plate - I have a couple of pretty impressive Lux V WX0S stars. I'd like to put one in a QIII, powered with a RCR123 and driven with a Badboy 500ma converter. Oh wait, 6V Vf at 500ma is only 3 watts. That's going to be boring now

ELM

Re: QIII Direct Drive - light, power and heat, oh my!

How did you get your direct drive luxeon to pull 2.2A from a RCR123???

I connected my UWAJ directly to a protected 3.7V RCR123 and it only drew something like 0.88 A!

Re: QIII Direct Drive - light, power and heat, oh my!

havand said:

How did you get your direct drive luxeon to pull 2.2A from a RCR123???

I connected my UWAJ directly to a protected 3.7V RCR123 and it only drew something like 0.88 A!

Click to expand...

I'm using a 800ma RCR123 unprotected cell from Lighthound. It comes hot out of a DSD charger reading 4.22 volts. Although that's a Radio Shack meter in the photo, I get identical readings with a Fluke 177.

Incidentially, I have also put a UWAJ in my Blaster Jr., powered with a 18650 cell. Readings are a little lower in that light, which could be due to emitter differences and/or switch resistance.

Re: QIII Direct Drive - light, power and heat, oh my!

My cells are protected and measured something like 4.13V

Could the effect be fromt he battery protection circuit?

Re: QIII Direct Drive - light, power and heat, oh my!

There is a smooth reflector available for the Q3!

An so20 minireflector will fit in there just about right.
Member photonfanatic has those readlily available.
With a little searching, there are even clearer glass lenses too.
With a little machining, the crenalated bezel can be cropped off a bit to allow a little more sidespill.

Good luck.


Edit:
That sure is a strong battery you have there.
A UXOK star may be the better move for a 2 stage pocket rocket like this one.

Some thermal grease goop in there under the star may also help to keep it cool.

Re: QIII Direct Drive - light, power and heat, oh my!

havand - I can't imagine the protection circuit is the problem. Either your cell has a higher impedance that what I run or something else is preventing good contact.

3rd_shift - Thanks for the phontonfanatic reminder. I had forgotten about him. 20mm reflector is ordered.

This mod is unreal - it beats my C3 with the KL5 head. To be fair, it's been a long time since I've run the C3. I need to install fresh cells. But no doubt the UWAJ is whiter. And as fun as it is to light up a wall with it, it's more fun outdoors. Looking forward to having the smooth reflector installed.