The auxiliary electric power supply for a vehicle has a first switch electrically connected to an IO end; a capacitor bank; a discharge resistance; and a controller. According to certain preferred embodiments, the thin layer or layers comprise fused silica, alumina or zirconia, and mixtures of these materials with other similar materials such as silicon carbide. The composite valve case has not only a cylinder function for allowing the valve body to slidably move but also a stator function for constituting a magnetic circuit.