US Patent 7538980 Actuator assembly

An actuator assembly according to one embodiment includes an inner effective annular magnet polarized radially, an outer effective annular magnet polarized radially, and a coil positioned between the inner and outer magnet structures. The magnet structures may be continuous magnets or constructed of multiple magnets. The coil may be a dual wound monofilament coil, where sections of the filament are wound in opposite directions.