ABSTRACT
The linear direct current (dc) homopolar brushless Permanent magnets (PM) motor has been developed from the voice-coil speaker microphone, but it develops control for progressive linear motion rather than oscillatory motion. The linear dc homopolar-PM motor has been developed from the voice-coil speaker-microphone linear electromagnetic device; it uses a flat topology and is applied for progressive linear motion; also, the travel may reach 100 mm or more. This chapter describes design issues of iron-core-backed or air-core-backed PM topologies, illustrates iron losses and geometrical optimization design, and investigates sliding mode precision control as applied in focusing a digital video camera. The iron losses are to be smaller as they are produced mainly by the local variation of the core magnetic flux density due to armature current. The chapter explores the digital video camera focuser analysis by dealing with the close-loop position control.
