Eddy currents

Exponentially damped pulses:

In normal cases the magnetizing current shape is a sine half wave. Magnet systems, which include conductive materials like iron, aluminum etc., may be shielded by eddy currents. These eddy currents firstly shield the magnet from the outer field and secondly might create an opposite field on the sharp end of a sine half wave. The opposite field might demagnetize the magnets again. In this case an exponentially damped pulse shape is appropriate.

epuls exponentiell

While a sine half wave magnetizer will take a big part of the pulse energy back into the capacitors at the end of the pulse, the exponentially damped pulse shape will burn all the enrgy in the coils resistance.

This may cause heat problems. For this reason the optimum pulse shape and peak field must be well considered.