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Topic: high power led driver (Read 5589 times) previous topic - next topic

Hippynerd

Its kinda relative, 350ma, is a little more than 1/3 amp, which is a lot for a microcontroller, but insignificant if you are talking about a car alternator, and a lot more insignificant than the smallest circuit breaker in your home.


Clearly the microcontroller wont be enough to run one LED, so you will need  power supply for the LEDs, but you may also need to consider heat, those LEDs will probably produce some heat that you may need to consider depending on how you are using them.
https://sites.google.com/site/rgbledcubes

focalist

#16
Dec 11, 2012, 07:58 pm Last Edit: Dec 11, 2012, 08:02 pm by focalist Reason: 1
You'd be surprised how little heat they generate- but they should be at least on one of those aluminum "star" heatsinks, running the raw LED "bead" without a heatsink for more than a few seconds will in fact cook the little beast.  On the plus side, one watt white LED's are less than a quarter each ordered from China.

I have had good luck using aluminum angle bracket and channel from the local Home Depot for heat sinking, and a tube of white lithium grease for compound.  

I have a homebrew LED photo strobe with over 140 watts of LED's on it now- I use a "repurposed" aluminum cable modem casing (about two pounds of thick aluminum) as the heat sink of the gods on that one.

On the subject of Power Supply- simple.  ATX computer power supply, ground the "power good" line and you have a high-capacity 12v and 5v supply... fan cooled, and cheap.. free, if you cannibalize an old PC... Use a fuse though, PC power supplies can kick out quite a bit of current!
When the testing is complete there will be... cake.

Headroom

Judging by the type of LED that you have linked to in your first post, which is a RGB LED you are not dealing with 5 LEDs but with 3x5 = 15!

If, on the other hand, you want to control the brightness of these 5 LEDs independently then things get more complicated.

There are quite a few chips available that can control 3 channels at a time but finding one that actually has a good dimming ratio at high current is not that trivial. But, it depends on what you actually want to achieve.

Te LT3496 can control 3 channels with up to 750mA each at a dimming ratio of 1:3000. I have not been able to find anything comparable. But then, that certainly will not result in a low cost solution, as that chip alone is around $7.

http://trippylighting.com

http://ledshield.wordpress.com/

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