"Turbocharged" P3D-CE outshines all others (while it lasts)

[brightnorm]

This is probably murder or at least 2nd degree lightslaughter, but I put a Fenix L2D-CE(3V) head on a P3D-CE (6V) body. The brightness is to a "normal" P3D-CE as a Cree is to a Luxeon. It is extraordinary to see so much light coming from such a little body, and my formerly impressive regular P3D-CE now seems almost ordinary by comparison.

I imagine the next doubling of LED efficiency will make lights like this commonplace, though the theoretical maximum efficency of 241 lumens/watt is beginning to loom as an impenetrable barrier, the photonic equivalent of the speed of light, sometime in the (not too distant?) future.

I picked up that figure from several posts by technically savvy CPF'ers. I don't know if it is accurate.

Brightnorm

 

[ThomasH]

Norm, you bad boy you!

I thought of the commercial with William Shatner where he helps the hotel clerk be "naughty"!

Do let us know how long it lasts!! May I suggest use in short burst rather than long burns!

Have fun!

- Thomas

 

[soapy]

What sort of heatsinking are you using?

Normally diodes are very funny about even a slightly over-voltage system, as they aren't an Ohmic device. Hence you get issues with unregulated lights and lithium betteries that give out 1.7V rather than 1.5V. Jumping from 3 up to 6 volts, I'm amazed they haven't gone pop!

 

[Ty_Bower]

though the theoretical maximum efficency of 241 lumens/watt is beginning to loom as an impenetrable barrier...

The ratio may be set by the laws of physics, but nothing is stopping us from throwing more watts at them. More watts makes more lumens.

 

[IMSabbel]

Also, if one were to reach that magical limit, this would mean all energy leaves the light as photons->no heatsinking required->push as hard as you can allowed

In fact, i guess thats why multi-die lights will be the future: At some point, the photon conversation in the phosphor will be the thermal limit of the light (you are losing 30-40% of the energy for each non-blue photon in the phosphour)

 

[Randy Shackleford]

I think I smell smoke.:naughty:

 

[brightnorm]

The light gets hot quickly and I don't use it for long periods, but based on everyone's input I'm a little concerned. Is there a danger of fire, explosion or any of the other lithium nastiness we've read about recently? If so, I'll stop using the light with this head/body combination.

Brightnorm

 

[TORCH_BOY]

Wow, Thats bright

 

[ensile]

this thread means nothing without beamshots.

 

[brightnorm]

Can anyone answer my safety question? (post #7)

Brightnorm

 

[ThomasH]

Hi brightnorm,

I am no expert, but I think the damage will be limited to the LED or circuit failing, non-catastrophically. You just won't have a working flashlight anymore.

As far as I know, the exploding lithium battery thing is most prevent if they are "run down" too low, and that these flashlights will blink when the batteries get low, so as long as you remember to stop using it, that shouldn't be a problem. However I understand it can also happen if you use two batteries of different charge and quality, although at a much lower likelihood, so the lithium blow-up is always a small risk in multi-Lithium battery flashlights.

I hope I'm not too far from right!

-- Thomas

 

[brightnorm]

Thanks

BN

 

[42]

I'd be concerned for the emitter and anything within a 6" radius.

 

[Ty_Bower]

As far as I know, the exploding lithium battery thing is most prevent if they are "run down" too low, and that these flashlights will blink when the batteries get low...

"Too low" for the L2D head is probably something well below 3 volts. Remember it was originally designed to run on a pair of 1.5 volt cells.

If you can manage to run a pair of lithium primary cells down that low, I'd wager you are in danger of reverse-charging one of them.

 

[orionlion82]

this really sounds wild!

"it makes it look like a luxeon"... just wow.

you need to thermal epoxy some heatsinks to that head...
i can suggest the tiny ones made for computer ram...
known as "Ramsinks"

 

[brightnorm]

I've been using my P3D-CE "Turbo" for three days so far. I'm careful to use short runs until the head gets very warm but not hot, and allowing it to cool before next use. To be safe(er) I'm on my second set of fresh batteries (first Titaniums and now Surefires), carefully voltage testing and ZTS testing before use.

I was going to try R-123s but decided not to push my luck.

Brightnorm

 

[L.E.D.]

I heard the theoretical maximum efficiency was 400 lm/w...

 

[2xTrinity]

I imagine the next doubling of LED efficiency will make lights like this commonplace, though the theoretical maximum efficency of 241 lumens/watt is beginning to loom as an impenetrable barrier, the photonic equivalent of the speed of light, sometime in the (not too distant?) future.

241 lm/W is the maximum for a broad spectrum white light source, similar to sunlight with the UV and IR portions chopped off.

Although the theoretical spectrum efficiency of phosphor LEDs can be higher than this, due to losses, I suspect a little over 200 lm/W will be a practical maximum for phosphor-based LEDs. Multi-emitter LEDs can do better.

I heard the theoretical maximum efficiency was 400 lm/w...

400 lm/W is the theoretical maximum for an RGB type white light source, with separate discrete LED emitters.

683 lm/W is the absolute highest possible for any light source (a 555nm yellow/green light)

As of right now, the only thing holding back the RGB type emitters is that the green component is very inefficient -- about 5% efficient (a 530nm green LED is usually only around 30 lumens per watt, with 600 being theoretically possible at that wavelength). Red and blue LEDs can be over 40% efficient. If we had a 40% efficient green LED, that would already be over 240 lumens per watt.

 

[soapy]

Ok, so I probably should have nipped off and patented this rather than posting, but if the green is holding things back so much, why not use a green doubler on an IR LED? Much in the same manor as a doubled green diode laser.

The other option would be to use a green emission phosphor rather than a green junction, and use the same tricks as used for pumping a white phosphor based LED.

A third option would be to couple the IR output (heat) into Xenon or something, and boost efficiency in the same way that halogen bulbs do.

Thoughts?

(Yes, I know I'm an expert in this line of things, but someone else might know the answers off the top of their heads. There's got to be a reason this isn't done.)

In fact, could you not cheat entirely, and use a red phosphor to down-convert a blue from one photon to two, and double the effective flux (after losses, of course)?

 

[orionlion82]

So about those beamshots...

and how long do you think it will last before it dies?

ive just gotten a wonderfully stupid modding idea myself...