Say I have a transformer of:

Vp = 230V - Primary Voltage
Vs = 110V - Secondary Voltage

N1 = 400 - Primary Turns
N2 = 191 - Secondary Turns

Ac = 4000 mm^2 = Core cross-sectional area

And I wanted to calculate the maximum flux (in Tesla) when the supply voltage is at 50 Hz and neglecting all losses, would this formula be the one I am after?

(Vp * 10^8)/(4.44FAcBmax) = N

Thanks.

 

Sorry, I meant Webers not Teslas.

 

If you only require the maximum flux (rather than flux density) you don't need to know the core CSA.

In any case I go back to basics

Vrms = 4.44*f*N*A*Bmax = 4.44*f*N*\(\Phi\)max

where f is in Hz, A is in m^2 and Bmax is in Tesla

If A is in mm^2 then

Vrms = 4.44x10-6*f*N*A*Bmax = 4.44x10^-6*f*N*\(\Phi\)max

So whichever you need, re-arrange to give either Bmax or \(\Phi\)max

I'm not sure where the 10^8 factor comes from in your equation - perhaps it applies to different units.

 

Sorry, the second equation with area A in mm^2 should just be ....

Vrms = 4.44x10-6*f*N*A*Bmax = 4.44*f*N*\(\Phi\)max

since area is of no relevance in the case of flux \(\Phi\)

 

Where has the 4.44 figure come from?

 

It's an approximation for

\(\frac{2*\pi}{\sqrt{2}}\)