LuxV Portable?

What is a LuxV portable?

It's the LuxV that you see in most of the current lights, like the U2 and the L5, L6, and L7's.

You have one in your sn2 clone I made for you. /ubbthreads/images/graemlins/smile.gif

It's known, colliqually, as the Luxeon V. Basically, this is the four-emitter LED which has become rather famous (or infamous) for its sheer output.

Oh. My Dad ordered a couple of LuxV's and it saud that they were LuxV portables. I thought he had made a mistake when he ordered.

i think portables are just "white" LuxV...

Yes, the Lux V portable is simply the white Luxeon V.

so, why does Lumileds differentiate them from their "regular" Lux V on their website?

Marketing.

The service life of the Lux V Port. is only 500 hours. The other colored Lux V have the normal 50K expected lifespan for LEDs. So in order to spin the marketing machine to cover up this deficiency, they add the "Portable" label, to indicate that it's meant for competition with conventional portable lighting devices (handheld flashlights). The 500 hour lifespan is still a 10-20 times lifetime increase over many bulbs that provide the same level of output, but is significantly lower than what is expected from an LED.

When the white Luxeon V first came out, it was not differentiated from the other Luxeon V products in any way. I would imagine that this marketing spin was only put on it after the lifetime issues became a big deal.

500 hours is all that Lumileds will warranty. In reality, some have had Luxeon V portable emitters last for thousands of hours with no huge drop in output.

The series-parallel design is an issue since Vf shifts over time and you only need one emitter out of 4 to shift signifigantly to potentially kill the entire array.

There's also the possibility for phosphor degradation - 5W is a great deal of heat for something so small.

I wonder if the 500 hour rated lifetime is based on maximum allowable die temp, or typical die temperature?

If the former, a LuxV in a well engineered assembly like a SF U2 might much longer than the 'rated' lifetime due to better thermal management.

Average Lumen Maintenance Characteristics
Heat sink temperature, Drive Current, Average Lumen Maintenance after 500 hours of operation

35° C 700 mA 90%
75° C 700 mA 75%
85°C 600 mA 65%


Note:
Luxeon V Portable is designed primarily for portable lighting and other applications requiring operating lifetimes of 500 hours and less. While the device will operate past 500 hours, its lumen maintenance cannot yet be characterized.

Thats a cop out, they have had plenty of time to characterize it now


Average lumen maintenance is dependant on heat-sink temperature. A recoverable light output loss may occur during the first 500 hours of operation.


In our case, that would be the temperature of the pad where we attach our Luxeons to.

Over driving beyond this 700mA significantly accelerates the degredation of the Luxeon.

[ QUOTE ]
idleprocess said:
500 hours is all that Lumileds will warranty. In reality, some have had Luxeon V portable emitters last for thousands of hours with no huge drop in output.

The series-parallel design is an issue since Vf shifts over time and you only need one emitter out of 4 to shift signifigantly to potentially kill the entire array.

There's also the possibility for phosphor degradation - 5W is a great deal of heat for something so small.

[/ QUOTE ]

Hey idle, I was waiting for someone to bring up the LML warranty issue. I contacted LML about warranties and they tell me, literally...

"We will only be responsible if it is due to the manufacturing default of
the LEDs."

... and how do we prove it is a manufacturing defect????