It isn't the current at the turn on that is the problem. It is that the curtrent builds in the inductor for the full half cycle instead of the 1/4 cycle that happens once the inductor has reached the continuous state. Normally at the continuous state, current is just reaching 0 at the peak voltage, for a pure inductor. If one turns on the voltage at this point, the current will follow the normal continuous cycle current. I know it seems counter intuitive but think about it. For the pure inductor, at the peak voltage, the inductor has no stored energy and can it would be as though it was already at its normal cyclic state if one started the voltage at this point in time. But that first half cycle is pushing current into the inductor for not just 1/4 cycle but a full half cycle. If it were a pure inductor, as stated above, the magnetic field that is created by the current in the inductor would be following the normal current and therefore the normal magnetic field. It is the zero cross starting that would put the current offset into the inductor that would have to decay over time. Remember, the inductor has zero magnetic field when the current is zero, this happens at the peak voltage in the normal cycle so starting at this time would cause the least current offset. It is only at the peak voltage that one can start the signal without causing a current offset that you describe. Dwight