[SOLVED] Cosfi

Does cos value affect efficiency in led drivers?

Hi,

without details hard to say.
Usually not, but in detail it depends on how you define "efficiency"... including source losses or not.

Klaus

There are efficiency %90 and Cos 0,9 writes led driver. Actually this is what I want to ask. If cos decreases, does it decrease in efficiency

No, they are unrelated. \( cos \text{ } \varphi \) is by the way, only the "displacement" part of the total power factor. There's also distortion power factor, which is usually more relevant for electronic device load. Both are only affecting apparent power, efficiency is defined as output power/real input power respectively luminous power/real input power in case of a light source.

See also https://en.wikipedia.org/wiki/Power_factor