Stepper motor for quartz controlled watch or clock - has permanent magnets to ensure saturation of defined regions of stator independently of materials used in main magnetic circuit

摘要

An integral stator (2) surrounding the rotor (3) is magnetically energised via the core (1) of a coil (4) by means of 1 sec. quartz controlled current pulses. The stator constrictions (5a,5b) on either side of the rotor (3) are maintained in a magnetically saturated state by the permanent magnets secured by adhesive and the regions (5a,5b) thus exhibit similar characteristics to an airgap. The magnetic materials employed for the core (1) and stator (2) can thereby be more freely selected. USE/ADVANTAGE - Enables wider choice of magnetic materials for motor construction whilst preserving mfg. convenience of integral stator. Permits greater scope for, e.g. value analysis in optimising costs and functional suitability via choice of materials.