I need to produce a magnetic field that goes from 0 - 80 kA/m (0 - 100 mT), which I can control the amplitude of, and change its polarity.
The diagram below outlines a couple of pieces of laminated transformer core I was given (blue), with a winding (red) and the green is where I need to place what I want to measure. This was apparently used by someone before to do the same things, but the rest of the set up is lost.
I am hoping somebody could advise me as to what to use to drive the coil to reach the the field I need and to control reasonable steps (5-10 kA/m) of the field, or any other set up or modifications that I could make to improve things.
I put 4 amps through the coil and measure 8 kA/m (10 mT) in the gap. This is the limit of the power supply I have, and the coil heated up quite a bit. I have some worry of the coil heating up and the limits. If I assumed a relatively linear increase that would require 40A, which seems like a lot.
There is a gap between the cores under the coil, and the calculation I have come across for these setups usually there is only one gap placed opposite the coils.
Any advice would be greatly appreciated, even if it is an alternative set up.