Luxeon Watts.....most Odd?

357 · Feb 21, 2004

When discussing personal sized flashlights, most of the Luxeon bulbs discussed are odd wattage (1 watt, 3 watt, 5 watt). What happen to 2 and 4 watt bulbs? Were there ever any 2 or 4 watt Luxeons? If not, why? Is there some technical reason for using odd wattage and skipping even wattage?

Deleted member 684 · Feb 21, 2004

They are made as 1, 3 and 5 watt luxeons. But fact is that we can drive them at anywhere in between or anywhere much higher.

People have driven 1 watts at 7+ watts, 3 watts at 10 plus watts, 5 watts at a shocking 15 watts.

It's what level you drive em at that matters, not 2 or 4 watt LEDs. LEDs differ from bulbs in that they don't use a coiled wire (filament) which gets very hot, to generate light.

357 · Feb 21, 2004

[ QUOTE ]
Nerd said:
They are made as 1, 3 and 5 watt luxeons. But fact is that we can drive them at anywhere in between or anywhere much higher.

People have driven 1 watts at 7+ watts, 3 watts at 10 plus watts, 5 watts at a shocking 15 watts.

It's what level you drive em at that matters, not 2 or 4 watt LEDs. LEDs differ from bulbs in that they don't use a coiled wire (filament) which gets very hot, to generate light.

[/ QUOTE ]

If I understand it correctly, in order to drive them past their design limit they need to be "heatsinked"?

IlluminatingBikr · Feb 21, 2004

357,

Heatsinking is just about always a good idea. It becomes even more necessary when overdriving. You can overdrive luxeons harder and longer with good heatsinking.

Deleted member 684 · Feb 21, 2004

You can also under-drive them, for more efficiency. For e.g., driving a 5 watt Luxeon star at 1 watt will definitely produce more light than a 1 watt Luxeon Star driven at 1 watt.

Lucien · Feb 21, 2004

If you think thats odd, then its worse when you find out what their wattages actually are. From the datasheets, the typical values (White) are:

for a "1W" - 3.42 V at 350 mA giving 1.197 W
for a "3W" - 3.7 V at 700 mA giving 2.59 W
for a "5W" - 6.84 V at 700 mA giving 4.788 W

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And heatsinking is needed for the 3 and 5W even when driven at spec. I think the majority of power supplied is converted to heat.