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Aaaagh, even 1W LEDs need heatsinks if you want them to have a normal life. And placing LEDs in parallel is far worse if they are not thermally connected (it's not a great idea even then, unless you can be assured that they are fairly closely matched).
And, it's better to use a constant current driver than those variable voltage, variable current regulators. Admittedly, this is not a major concern, but the dedicated devices are smaller and cheaper (although typically not variable)
And, it's better to use a constant current driver than those variable voltage, variable current regulators. Admittedly, this is not a major concern, but the dedicated devices are smaller and cheaper (although typically not variable)
The star led's do, if only smallish.
One shown is just that only adjustable to suit the need.
Yeah (maybe), but the 1W LEDs in the video aren't on a star.
CREE has a very useful document discussing thermal management. This doesn't give the relationship between die temperature and lifetime, but points to another document that gives similar information for each of many, many, many products.
For devices tested at 2 different temperatures (often 85C and 105C) you can see the reduction in lifetime (often the higher temperature tests are operated at a lower current, and that is insufficient to maintain a similar lifetime).
There's a good graph here showing the "time to 50% brightness" that clearly indicates why you need to keep the die temperature as low as possible.
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