For example, if I have an inductor that produces 1 henry and it has a .75" diameter X 10" long metal core with 1000 permeability, how do I figure out how many gauss this electromagnet will produce?
I've looked a lot, but I can't find reference to this.
Wouldn't it be a function of the applied voltage? Meaning, the gauss would change as the voltage varies.
Yes, it would change, but voltage is implied in the unit measurement of one henry.
H = Ohm * s = (J*s/C^2) * s = (J * s^2)/(Amp * s ^ 2)
= (W * s^3)/(A)(s^2) = W*s / Amp = J /Amp
--------------------------------------------------------
1 Gauss = (10 ^-4 Kg) / C^2 * s = (10^-4Kg)/(Amp)(s^2)
or
1 Gauss = (10^-8 J)/Amp * cm^2
see,. heres the problem....
either way you look at the magnetic field, you have this extra variable.. either in dimension or in mass.
Gauss or Tesla, is a complex Unit. like Joules
it contains the integrals of of the derrived units
like force, acceleration, amperage, mass, area
Henries, Ohms, Amps,.. these are components of the larger picture.
The way you would need to go about this, is to use the electromagnetic equation, with the dimensions of your coil
and by the current (Amps) you can determine how many Gauss the coil would produce.
looking at it like that, ( in Teslas, which is 10^4 Gauss)
T =
4(Pi)(10^-7)*(number of turns ^2)*(Amps)/ (Length)(Area^2)
Hope that helps.
Quote from: rukiddingme on August 21, 2010, 08:15:26 AM
For example, if I have an inductor that produces 1 henry and it has a .75" diameter X 10" long metal core with 1000 permeability, how do I figure out how many gauss this electromagnet will produce?
I've looked a lot, but I can't find reference to this.
Hi,
You may find these links useful if you go through on them carefully:
http://sci-toys.com/scitoys/scitoys/magnets/calculating/calculating.html
http://www.electro-tech-online.com/electronic-projects-design-ideas-reviews/85249-electromagnet-strength.html
If you do not know the B-H curve for your metal core, then if you know its material, perhaps somewhere on the net or in a textbook you could find it. Otherwise, you may wish to choose a core with known B-H curve or any calculation can be only an approximation if neglecting the permeability change during excitation, your result may be close to the truth but not so precise.
rgds, Gyula
yup.
the equation i gave above is for an "air-core".
if you use a core the equation changes with flux intensity,
also the core has a different permeability than air, so that also is taken into account,
Yes, see a simple equation here:
http://hyperphysics.phy-astr.gsu.edu/hbase/magnetic/elemag.html#c5