The virtues of under-driving leds

[oz93666]

Component (chip) led s are fairly cheap now ($4/100W , ebay) so it makes good sense to under-drive them.

Driven at 25% rated power they are around 20% more efficient(lumens output/Watt) , the saving in electricity over a lifetime will more than pay for the extra cost of extra chips.

Also, a lest costly heat sink is required , if any,.... and leds have a much longer life expectancy if run cool.

 

[Colin Mitchell]

25% of rated current is a bit too low.

 

[oz93666]

25% of rated current is a bit too low.

A bit too low for what ?

You obviously need more chips to get the same light output.

I thing the gain in efficiency is closer to 30%... So lets say you need 10,000 lumen of light , you can either use one 100w chip and drive it at recommended max. or use 3 driven at 25W the light output is the same but you only use 75W instead of 100W, with the same heatsink life expectancy is 2 or 3 times longer , because of cool operation temp.