# Estimating inductance change by eddy currents

I have a planar coil with inductance L, operating at a given frequency. Now I want to estimate the eddy currents, which are induced in a piece of metal, which is placed in front of the coil, and the change of inductance caused by this eddy currents.

Which would be the best approach to this, by calculating the field equations, or is there any simpler approximation possible?

• How about a sketch with dimensions. – Andy aka Jul 21 '16 at 7:19
• I'd expect that eddy currents not only affect the inductance but maybe even more the Q factor (if the coil is part of a LC circuit). – Curd Jul 21 '16 at 8:47
• @RobertAlpha: What do you mean by "estimate"? Do you need just a qualitative answer of a quantitative? – Curd Jul 21 '16 at 9:46
• What I'd need is a rough estimation, by how many percent the inductance will change, between the metal is present (in a given distance) or not, if such an estimation is possible – RobertAlpha Jul 21 '16 at 11:23