# Magnetic Flux Calculation

1. Apr 18, 2008

### burnit

Hi All,

I have setup a small experiment with a pulsing coil--Coil 1 to produce a pulsed magnetic flux, say we do not know the specifications of this coil like number of turns on the windings, voltage to the coil, flux density etc.

There is another coil --Coil 2 of known specifications placed in close proximity to this coil 1 which is creating a voltage in coil 2 from being induced from the pulsed coil.

My question is:
Is it possible to calculate the magnetic flux produced from Coil 1 if we were to measure the voltage produced in coil 2 of known specifications?

Thank You

2. Apr 18, 2008

### burnit

I forgot to ask another question:

What is the correct term to use for how magnetic flux travels through different types of materials, water, air, soil etc.
Is this the same as Acoustic properties of various materials?

Is there a site i can look up to see what effect different materials have on magnetic flux travel?

3. Apr 18, 2008

### Phrak

To answer your first question, basically, no you can't. The magnetic flux, and flux intensity are proportional to NI.

N is the number of turns. I is the current. Without any information as to the signal driving the coil, you uniquely determine neither I nor N.

4. Apr 18, 2008

### burnit

Hi Phrak,

Please excuse my ignorance here on the subject but it sounds strange that if we know the driving coil specifications & driving signal etc we could calculate the required coil specifications to produce X voltage in coil 2, if i have this correct.

Why is it that we can have a voltage produced from coil 2 of a known specification & not know what magnetic flux it takes to produce it?

5. Apr 19, 2008

### Phrak

Umm...Originally you stated that the nature of the driving coil wasn't known. Maybe we've all been talking at odds...

After some careful re-reading of your question, I think I'm mistaken, either way. It depends.

I'll assume your coils are axially aligned and that coil one is being driven by a sine wave generator. By flux, I assume you mean the total flux.
$$\Phi =\int B\cdot da$$

If you don't know the dimensions of coil one you really can't know how much of it's flux is passing through the second coil.

I would guess that there are things you are taking for granted, after working with it, like it's orientation, it's axis, its diameter and length, how close you can put it to the second coil... I'd blithely assumed these were unknowns.

I need more specifics. Is it sine wave driven?

Last edited: Apr 19, 2008
6. Jan 1, 2009

### BrockLee

Hi all.
There seems to be a variable of wire diameter left out of both the Amatuer Radio Relay Leagues and your post that is, isnt the distance inverse inductance affected? Shouldn't this matter? I have many concurrences that suggest so.

7. Jan 1, 2009

### TVP45

Since I've done this for commercial products, I can say that you can only know the flux produced by coil 1 that also links coil 2. And, to be more correct, you must say something about the impedance.