Anyone tried the Z-led P4's ?

[Novastar]

Hi Phil... good to hear from you again...

I also just saw on a P4 site that the 1000ma is really only referring to "peak fwd current", which it details as the following:
------------------------------------
The surge current describes at what maximum current the LED can be operated short term.
Attention!
Here the controlled surge current in the range of milliseconds is meant. A LED will IMMEDIATELY BE DESTROYED if this current will be used longer term.
-------------------------------------
I don't know if that's pretty much the same with the K2 @ 1500ma, but I can only wonder...

Know anything about this Phil? I mean, MY assumption is that the Lux K2 Green's "max cont. current" of 1500ma... is NOT meaning that if you run it at 1500ma for a long time, you'll fry it, lol

Sounds like 1000ma on the P4 Seoul will kill it if you do so for longer than 1s or so.[/u]

[neophyl]

Got a link to the site you saw that on ?

In my impknight sabre the P4 is being driven by a konlux 1A constant current source. I was certainly using it for more than a few minutes. Not sure of the max time but it was certainly on for more than 10 minutes at any one go and over an hour total and its still working perfectly.

The datasheet I have for the P4 has a note about not driving at rated current for more than 5 seconds without a proper heatsink but thats apllicable for all the high power leds like luxeons.
It also states that it can be pulsed at 1.8A if the duty cycle is 10% or less with a frequency greater than 1kilohertz so it can certainly withstand higher currents for a few microseconds. 1A appears to be the max continuous though. Like the K2's 1.5A continuous max.

[darthdan]

I'm not driving mine off of an MR board, just 4.5V and a resistor.

Is a 1 ohm 2watt resistor the right one for these?

[Novastar]

Wish I could tell you, Darthdan... my guess is that it would be fine, given your battery setup. But I don't know how the P4s work.

NeoPhyl... here's the link
http://www.leds.de/product_info.php?...240-Lumen.html

I *STILL* don't get the "240" lumen thing. Ha. My left uh... ... uh... leg. Yes, my left LEG.

[neophyl]

You might find this useful http://www.luxeonstar.com/resistor-calculator.php

If the led does have a 3.8v forward voltage then at 4.5v @1ohm you are only going to be pushing 700ma through the led. You need a 0.7ohm resistor to get 1amp through it. If your P4 actually has a higher forward voltage like mine (4.05v) then thats going to be even less current through it.

You will get 1a through if you use a 6v supply and a 2.2ohm 3watt resistor. You wont get full capability out of it at 4.5v.