The eddy currents in an infinitely long iron sheet caused by an alternating magnetic field are analyzed. At first, it is shown that any static hysteresis loop can be simulated with the help of a digital computer, as far as all the history of 

 is known. Using this computer program, the solution of the eddy current equation under the given initial and boundary conditions becomes possible considering the magnetic hysteresis in a general form. The proposed method can be available even under the voltage excitation. Some results of digital computation are shown : dynamic major loops under both sinusoidal current and sinusoidal voltage excitation, minor loops, and 

 and 

 distributions in an iron sheet under superimposed alternating currents.