can someone explain this to me?

[Blacksmith1]

2813where Po, i is the output power of the ith output.

[James86]

what kind of formula is that?

[Blacksmith1]

It's for power efficiency. and the one I need a definition for is
Σ
I know this is sigma but what is it used for in this equation? what value gets inserted there?
I've got most of the rest figured out as far as n being the effeciency, Po, i is the output on the i th bus p in is power in. but I can't get a lock on that sigma thing. (think anyone will guess that math isn't my strong point?) and by the way, is this considered algebra? or am I moving into unkown (by me) territories?

[Saryn]

That is advanced Algebra I believe. Makes my head hurt looking at it this late. Can't recall the symbol either.

[Saryn]

http://en.wikipedia.org/wiki/Summation

Try that link. Might help you figure it out better than I can atm :P

[Blacksmith1]

I guess my mom was right about me needing it one day.... shoulda paid more attention in school. at least now i have a better starting point. I'll look at it again in the morning.:sleep:

[ET3D]

In case you need some more help, looks to me like what it says is: Sum all the outputs, divide by the input and multiply by 100.

[Blacksmith1]

Great, now I just have to figure out how to get the values for the output. do they make a kill-a-watt for the dc side of a PSU?