plese help me, i've being searching for a long time and this website was the only one with basic information

please could you give me FOUR(4) formulae for calculating the efficiency of a transformer? pleassssseeeeeeeeeee! thanx alot, and could you please send it within the next 24hours? Thank you so much. have a nice day. THANK YOU

 

Four? Sounds like homework, and no one here is going to do your homework for you.

 

Hey i've been searching for a load transformer efficiency formula and all i've found (which i don't think is right) is
voltage in * current in = power in
power in * cosine of the equivalent primary resistance = Ans in

then voltage out * current out = power out
power out * cosine of the equivalent secondary resistance = Ans out

finally transformer efficiency (%) = (Ans out * Answer in) * 100

Please help me... [email protected]

 

Sorry, but you should do your own research and or homework.

Your welcome.

You can try http://www.mikeholt.com

I did a search on transformer calculations and got 12K hits, I am sure somewhere in there, YOU can find what your looking for.

MJH

 

Responding to Looniebunny's query:

Hopefully, the following are the four you need:

1) The usual expression, when the total losses are known for a particular load, then:

%Eff = 10^2 x Output / (Input + Losses)

2) If % iron losses, Pi, and % copper losses, Pc, are known for a particular load, then:

%Eff = 10^4 / (100 +Pi + P c)

3) If Pi and Pc are known at full-load, and efficiency is desired at a fraction, X, of full-load, then:

%Eff = 10^4 / [100 + (Pi / X) + (Pc x X)]

4) If maximum efficiency is required, and ratio of losses, R = Pi / Pc is known, then:

%Eff = 10^4 x Sqrt(R) / [100 x Sqrt(R) + 2 x Pi]

Regards,
Phil Corso, PE {Boca Raton, FL, USA}
[[email protected]] ([email protected]) {[email protected]}