| 摘要 |
<p>An arrangement of magnetic field strength detectors useful for the communication and/or control of a linear electric motor is provided in which the arrangement either comprises a set of at least two detectors (12, 13, 14) separated from one another circumferentially in the same plane or a set of at least two detectors (18, 19) longitudinally separated by half a full cyclical pole pitch of the magnets of the stator to which the arrangement is to be applied. The first arrangement in which the detectors are circumferentially separated allows the detrimental effect of unstraightness of the stator (e.g. sagging due to gravity) and/or any misalignment of magnets in the stator to be reduced. The second arrangement in which the detectors are longitudinally separated allows two signals which are an anti-phase to be provided, these signals being capable of being combined so as to eliminate any signal components due to undesired parasitic magnetic fields. The two arrangements may be combined in a preferred embodiment.</p> |
