Alright, well, that didn't last long. Tried a 14500 with this mod, about 20 seconds in and *poof*, no more emitter. Ah well. Good while it lasted.
QTC certainly opens up a lot of possiblities for creating 'ramping' brightness flashlights.
I doubt it,but I can be wrong.. are there bigger pils avaiable? It would be cool to use it with sst-90 :D
Just use several of them. Middlesex University Teaching Resources make the stuff. Ask them.
The smaller, the less resistance, so why would you want bigger?
Because one pill can only handle 10A
But a bigger one would handle less.......
The limit is I2R (Current squared x resistance) - current is the limiting factor since each pill can handle 400W - but at a maximum of 10A and 40V. Two of them in parallel will handle 10A each or 20A which is way more than an SST-90 will pull. And an SST-90 certainly doesn't need 40V to light up.
Yes, the resistance will be halved, but since it starts from an enormous value - greater than the 2 megohms my body offers - this is no big deal.
As far as my meters (Even the Fluke) are concerned, the uncompressed value of a pill is infinite. The only measurement I can get is if I touch the metal on both probes where the resistance is my body, not the pill. I can scrounge a Megger (Megohmmeter) from work and check a pill with that. Given the nature of quantum phenomena (I had to do quantum mechanics for three years but it was 30 years ago) I wouldn't be surprised if those meters registered infinite resistance too. I'd need a hard vacuum to measure that properly as the conductivity of the air around would become significant at those levels of resistance.
I got mine from http://www.technobotsonline.com/qtc-pill.html because there wasn't a minimum order and the postage (internationally) was cheaper. Unit price is higher, though.
Well in the midst of a rather technical discussion, my mind went in a different direction after that post...
On a more serious note, have you run run the light on a "low" beam long enough to tell if you can actually extend battery runtime, or is the draw on the battery the same either way?
Without strain gauges this would be hard to measure. I'll stick mine on the box and try it. Because of the way the QTC works, I'd expect runtime to be dramatically extended.
The losses within the pill ought to be negligible. If they weren't the pills would melt fast. I know the current draw without a pill and can chart with and without pill runtimes. Obviously, it depends on just how much the pill is compressed.
I did in fact run my E07 over night (at least 8 hours) on a low setting, but not the very lowest. Didn't measure full runtime, but the fact that it was still running in the morning was proof enough for me.
By that logic, a battery sitting alone is heating the air between its contacts.
I have a qtc sandwich idea i had for my E07 i want to share, i cant try yet since my qtc pills order hasnt arrived and i forsee a couple of problems like height of the sandwich, but it might clear ok, cant tell for sure.
Its a sandwich between 2 old AA positive contacts, a third contact could be soldered to the one on the top to ensure contact with the AA cell, the foam ring between the contacts adds support, stability and also prevents contact, i suspect could add consistency to the level changing too.
The nipples ensure max pressure to the QTC pill, so maximum brightness could be achieved.
Still the height among other things could make this fail, will try it later even if my pills dont arrive, if height is too much i guess i can dispense the nipple that ensures contact with the cell and replace it with just a solder blob... lots of options to evolve this little sandwich
A bit of a necro but I just brainstormed. 
I just had an idea. I tried different things over time to diminish the wear of the QTC in this flashlight. Nothing really worked. Now I remembered the AAA to AA battery adapter. I put the QTC between the positive end of the AAA battery and the adapter and closed it. The adapters' pressure keeps the QTC in place but as the positive end of the adapter has a bit of wiggle room it's perfect for compressing the QTC. You loose a bit of runtime compared to the AA but save on QTC.
It goes so low the camera won't pick it up.
Presumably the wear is aggravated by the high friction of the foam-like material? Basic logic suggests that a cheap low-friction surface would be beneficial - ie. a bit of foil glued on. You would think there would be such an option manufactured for frictional applications