P7 questions

[mandd]

I imagine a lot of us are thinking about what the P7 can do and how we can use it. I have a couple of specific questions that I'm hoping some more knowledgeable members would have a feel for. The first is, in a given reflector, what will the beam be like compare to a P4 or a Cree. For example, I have an Ultrafire C2 Q5 that has a decent sized reflector. In fact it has a flat area at the base of the reflector with a small hole for the Q5. That flat area looks to be about 1/2 inch in diameter--intriguingly close to the size a P7 would need. The C2 is fairly throwy, with the Q5 centered at the bottom of the reflector. If a P7 was put in there, can anyone predict what the beam would look like.
Second, shouldn't this be a more efficient emitter than what is currently out there at comparable lumen levels? For example, if I only want, say 250 lumens, I'm extrapolating it would take about 1000mA (at ~3.15v). A C bin might even take less. This should significantly be better than a Q5, right? Would it also be cooler at that low (for a p7) output?

Thanks very much for your thoughts!

 

[Jarl]

Because it's running 4 dies, it can run them all at a lower current (i.e, 4 at 250ma=1 at 1000ma). Since LED's are more efficient at lower currents, the P7 at 1000ma will generate more light than a Q5 at 1000ma, which runs into overheating/droop problems.

 

[Gunner12]

It would compare closer to the Luxeon V, which was another Quad Die LED.

It should be a bit more efficient, but it(the P7) is essentially 4 Seoul P4s on one die.

It should give a wider beam if you place it in the C2 reflector. This is because of the larger emitting area.

 

[mandd]

That's kinda what I've been thinking.

Thanks!

 

[phantom23]

Check this post out.

 

[mandd]

Thanks Phantom,
That's *exactly* what I was thinking about--don't know how I missed that!

 

[phantom23]

I'd try this with Ultrafire C8. It has bigger (deeper) reflector for more throw (hopefully).

 

[yellow]

I have a triple-cree setup (P3) on my town (dynamo) bike and a single Cree (P4) inside my 6P.
the dyno pushes the triple with about 600 mAh, the single gets 1A max from the flupic.
when the single is on, the triple seems switched off

dont expect too much of an effect of "led at lower current being more efficient"


PS: still waiting for the 1st handful of users that experience die burnouts because of the differnent Vfs and the high current with the P7.
Simply cant understand why they are not wired in series.

 

[Jarl]

Simply cant understand why they are not wired in series.

Not only would the required voltage be scary, but it's harder to manufacture. As it is, half the bond wires can go to a +ve plate, and then the other half need fiddly connections, instead of them all needing fiddly connections as it would be if they were in series. This helps keep costs down (good!)

 

[phantom23]

One more UF C2 P7.