Shading coil magnet of new design

A reliable analytical method of new design of shading coil magnets is described. In the magnets of new design, with equal shaded and unshaded pole-face areas, the fluxes of the shaded and unshaded poles are made equal in magnitude with substantially sinusoidal time variation. The phase angle between the two fluxes can be made to exceed 80 degrees so that the minimum of the variable holding force is more than 70% of its maximum value.