A first member has a magnet assembly that includes at least one permanent magnet pair, and a second member includes an electromagnetic coil. A control circuit controls the supply of power to the electromagnetic coil as well as regeneration of power from the electromagnetic coil. The permanent magnet pair generates its strongest magnetic field along a magnetic field direction on homopolar contact planes where first magnetic poles contact one another, outward from the center of the permanent magnet pair along the magnetic field direction. The electromagnetic coil is positioned such that current will flow in a direction intersecting the magnetic field direction.