# TRANSFORMER EFFICIENCY

Discussion in 'Electronic Design' started by uchethegenius1@gmail.com, Jan 9, 2014.

1. ### Guest

How do you derive the efficiency of a transformer from the first principle of electric circuit.

, Jan 9, 2014

2. ### Phil AllisonGuest

** Efficiency = power out / power in ( times 100 for percent ).

Now YOU get to explain WFT you really want to know.

..... Phil

Phil Allison, Jan 9, 2014

3. ### George HeroldGuest

Hi Tim, If you wanted to keep it simple isn't there some leakage inductance(or is leakage the wrong term) that you see modeled as being in parallel (I think) with the primary, and given the leakage inductance and the windingresistance you could calculate some loss.

George (not a transformer guy) Herold

George Herold, Jan 9, 2014

If you are really determined, you could try studying some of the heavy
electrical engineering textbooks from the 1940s and 50s. They will give
the sort of information you need, but mainly aimed at the design of
massive power-distribution transformers where you really do have to
calculate first and build later.

That will give you some idea of the factors at work and the ball-park
figures you can expect, then you will have to scale everything to suit
the size of transformer you are interested in.

5. ### Robert BaerGuest

WHAT "first principle"?
From the theoretical definition? Answer is 100 percent.

Ignore the bushwah and look at losses: IR winding losses and induced
magnetic core losses; that will get you close to measured losses.

Robert Baer, Jan 10, 2014