# Solonoid with iron core

1. Apr 27, 2013

### 215

How do i calculate the amound of windings I need to make an solonoid electro magnet with around 1 T..

I checked with google, and there seesm to be a lot of different formulaes which confusses me alot..

2. Apr 27, 2013

### FireStorm000

One Tesla is a significant magnetic field for an electromagnet in continuous operation, so unless you're talking about pulsed operation, you're not going to like the answer. The exact answer will vary depending on where you measure the field, what metal/alloy your core is made of, and so forth, but it's somewhat beyond what one can achieve with a homemade electromagnet. If you can give some additional detail, I can provide you the relevant equation.

3. Apr 27, 2013

### Simon Bridge

4. Apr 27, 2013

### SteamKing

Staff Emeritus
Current MRI machines operate between 0.2 and 3 teslas. A standard strength MRI with a 1.5 T field costs between US$1.0 million and US$1.5 million. In order to produce this field strength, the MRI machines use cryogenically cooled superconducting electromagnets. Good Luck with a plain old iron-core solenoid!

5. Apr 28, 2013

### 215

Well 1T Where maybe a bit extreme.. its more like 0,46T, and i want it at the side, or int he bottom, and yes it has to be pulsed..

I've been using different formulaes, but no one seesm to take the iron core with in their calculation, which results in different number of winding.. I am only using 1Amp.

First one is using Biot savart formula.

B(z) = $\frac{µ0}{2pi}$*$\frac{µ}{z^3}$

Where µ here is the dipole moment.. µ= N*i*A

Second one
B=µ0(1+xm)H

Where xm =5*10^3 is the ironcores suscebility, and H is the magnetic intensity which is the
H=M/5*10^3
M=N*I*A/Vol
A=0,01*0,01
Vol=0,01^2*0,03

Here is the iron core taken into acount, but my winding number is too high.. around 10000..

So which one should i Use..