350mA, 1 watt LEDs

[Bill Bowden]

I have some white LEDs made by MAXPHOTON rated at 3 volts and 350mA.
They are mounted on a 3/4 inch disk with solid aluminum back side, but
they get fairly warm at 250mA. The model number is XT-D20.

Is 350mA the maximum rating? or recommended operating current?

They seem to be very bright (and warm) at 250mA, so I'm wondering if
it's worth the trouble to add more heat sink to obtain maximum
brightness?

How hot can these things get, and how is the lifetime effected
by current and heat?

-Bill

 

[Watson A.Name - "Watt Sun]

In article <401eed4d.0309110839.31884b40@posting.google.com>,
HoldenCaulfield@att.net mentioned...

I have some white LEDs made by MAXPHOTON rated at 3 volts and 350mA.
They are mounted on a 3/4 inch disk with solid aluminum back side, but
they get fairly warm at 250mA. The model number is XT-D20.

Is 350mA the maximum rating? or recommended operating current?

They seem to be very bright (and warm) at 250mA, so I'm wondering if
it's worth the trouble to add more heat sink to obtain maximum
brightness?

How hot can these things get, and how is the lifetime effected
by current and heat?

Go to Don Kilpstin's LED website and look for the info on Lumileds
Luxeon Star, which seems to be very similar to the ones you have.
http://members.misty.com/don/ledx.html

-Bill

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[Bill Bowden]

Watson A.Name - "Watt Sun" <alondra101@hotmail.com> wrote in message news:<MPG.19cf55a8566837a19896bf@news.dslextreme.com>...

In article <401eed4d.0309110839.31884b40@posting.google.com>,
HoldenCaulfield@att.net mentioned...
I have some white LEDs made by MAXPHOTON rated at 3 volts and 350mA.
They are mounted on a 3/4 inch disk with solid aluminum back side, but
they get fairly warm at 250mA. The model number is XT-D20.

Is 350mA the maximum rating? or recommended operating current?

They seem to be very bright (and warm) at 250mA, so I'm wondering if
it's worth the trouble to add more heat sink to obtain maximum
brightness?

How hot can these things get, and how is the lifetime effected
by current and heat?

Go to Don Kilpstin's LED website and look for the info on Lumileds
Luxeon Star, which seems to be very similar to the ones you have.

http://members.misty.com/don/ledx.html

I found a data sheet on the Luxeon Star at the Luexon website and
it looks like 350mA is maximum at 25C ambient. They derate the current
as temperature goes up, it's about 300 mA at 50C ambient. Interesting
that all the test data is at 350mA. I think I'll just use them around
280mA which should be safe at 25C ambient. I mounted them each on a
4 square inch aluminum plate and they barely get warm.

-Bill