Patent attributes
An electromagnetic exciter includes a magnetic circuit device composed of an outer yoke, a flat magnet arranged within the outer yoke, and an inner yoke mounted on the magnet, and a casing within which the magnetic circuit device is contained. The casing has a flat plate and a cylindrical wall. A magnetic gap is defined between the side wall of the outer yoke and the outer peripheral wall of the inner yoke. A voice coil is secured to the flat plate of the casing and inserted into the magnetic gap. A suspension extends between the cylindrical wall of the casing and the magnetic circuit device so that the magnetic circuit device is supported by the casing. An annular weight is secured around the outer yoke. The suspension has openings. The weight has projections loosely fitted within the openings.
