Large Number of High-Power Leds

[drdichotomy]

I want to drive a bunch of 5 and/or 10 watt high power LEDs but I am not clear on how I should power them (indoor so 120VAC source). I've seen some very expensive drivers but it seems that there are other cheaper options.

Could someone explain the pros/cons of using a converted computer psu or one of the following power supplies?

http://www.powerstream.com/ac-2420.htm
http://www.powerstream.com/AC-A0407.htm
http://www.powerstream.com/Amps-Watts.htm

 

[TigerhawkT3]

You might try a unit actually intended for driving LEDs. I don't know what your price range is, but they're about $30. If you're really brave, you could make a cheapo driver with a rectifier and caps and just buy enough LEDs to run off 167VDC, which, if they're power LEDs (Lux, Cree, etc.), would entirely defeat the purpose of cheaping out on the driver. That option would be kind of hazardous, though, so I'd recommend just going with a Xitanium.

 

[Oznog]

Or as more of a budget thing, drivers from Kaidomain/DealExtreme.
Be aware that not all high powered LEDs have electrically isolated slugs, and the backings on Star boards may or may not provide the needed electrical isolation. So if a person were to try to mount 25x 3.4v nonisolated LEDs in series with a ballast resistor on rectified, filtered 120V for example, then not only can they not be mounted on the same heatsink but all the heatsinks would be electrically "hot" which requires them to be insulated and enclosed which largely defeats the function of a heatsink.