LINEAR MOTOR AND TRANSDUCER ARRANGEMENT THEREFOR

摘要

An improved linear motor which compensates for manufacturing or assembly errors in the positioning of the magnetic field detectors. The linear motor synthesises a correction signal which can be simply combined (for example added) to the output of one of the magnetic field detectors so as to ensure that the magnetic field detector outputs have the correct phase relationship. This in turn ensures that accurate positioning of the rotor relative to the stator can be achieved. In a preferred embodiment, a deliberate error is introduced into the positioning of the magnetic field detectors and this error, plus any error due to manufacturing or assembly tolerances, is corrected using the correction signal. This allows a simplified correction circuit which only corrects for phase offset errors in one direction to be used.