through the poles of the polar piece 3b is greater than the permeance for auto reclosing itself through the poles of the polar piece 2b this is due to the fact that the poles of the polar piece 3b are directly opposite the poles of the polar piece 3a which is not the case of the poles of the polar piece 2b with the rotor still in the same position let us examine the path followed by the fluxes coming from the pairs of poles of the rotor the magnetization axes of which are inverted i e are directed from the lower stator a toward the upper stator b these fluxes are collected by the upper polar piece 2b and are routed by the magnetic circuit to the end a of the core at point a a large part of the flux then travels through the core 6 in the direction from a to the other end b of the core i e in the same direction as for the adjacent pairs of poles the fact that the fluxes of all of the pairs of poles of the rotor are combined in the core is attributable to the fact that in the case under consideration the polar piece 2b of the upper stator is magnetically.