# Inductor/coil/choke design confusion

1. Jun 26, 2012

### engineerting

Hello all,
i have an equation for flux density taking the inductor chrecteristics into account as

Bmax= (Vrms * 10^8)/(4.44*A*N*f)

but the company i work for has given it at

Bmax=(Vl * 10^4)/(4.44*A*N*Vss)

where Vl = voltage across inductor.

i am finding alot of variation for equations for the paratmeters of inductor/choke design.

i was wonderign if someone could shed light light on this confusion??

thanks

2. Jun 26, 2012

### sophiecentaur

You would need to define the symbols in those formulae first. Is the second formula just for a particular circuit? (Vss seems to be a supply voltage?)
What's the background to this?

3. Jun 26, 2012

### engineerting

Vrms = rms of supply (what i understood this to be)
A = cross section of core
N= number of turns of coil
f= frequency of supply
Vss = supply voltage

the equations given to me for choke design work but are not accurate so i started to search around for an answer. there are lot of variations in the equations and also for Inductance i found the same thing.

4. Jun 26, 2012

### sophiecentaur

The formula you have been given must be making assumptions about the frequency being used and, I guess, is supposed to make life easier for you to get an answer. It looks totally wrong and it is not 'dimensionally correct' because there is a V, top and bottom. But it may work in the particular context that they want you to work.
I should ask your boss what to do, if that's acceptable in your organisation. He is paid to sort that sort of thing out (?).