A feed-through for conducting electric current is provided that includes a flange, which has a through-opening, in which a conductor for electric current is held by an insulation component and is connected to the flange so that the through-opening is sealed off. An error amplifier included in a control circuit generates an error signal in accordance with voltage difference between an output voltage and a reference voltage. One of the first and the second AP pinned layers consists of cobalt and the other one includes cobalt-iron.