What could be causing unexpected results in my magnetic circuit?

[Cahane]

Hello,

I have designed a magnetic circuit.. C core with an air gap. I calculated the circuit as well as doing a simulation on it using FEMM software. The core is from 1018 steel. My calculation and simulation gave almost similar result.. So, there is no problem in my calculation or simulation. The problem is, when I tested the magnetic circuit.. the result is very different (low than I expected).. Can somebody suggest or give the suggestion on where when wrong? Is there anything that I should consider?

Thanks,
Cahane

 

[Bob S]

Could you please post a drawing of the electromagnet?

Very roughly, if the gap is small relative to the pole tip width, the magnetic field in the gap should be about

B = μ₀NI/h Tesla

where NI = amp-turns, h = gap height, and μ₀ = 4π x 10^-7 Henrys per meter.

Bob S