Patent ID: 6940278
Filing Date: 2005-09-06
Classification: G01D

Abstract:
1. An angle transducer comprising a first disk, the rotor ( 1 ), with circularly arranged and radially directed receiver electrodes ( 2 ) and a second disk, the stator ( 4 ), equipped with circularly arranged and radially directed transmitter electrodes ( 3 ) arranged at the same radius as the receiver electrodes ( 2 ) and with a fixed separation between the receiver electrodes ( 2 ) and the transmitter electrodes ( 3 ) on the two disks ( 1 , 4 ), whereby the disks ( 1 , 4 ) are arranged coaxially and rotatable relative to each other, and the disks ( 1 , 4 ) are further separated by a thin air-gap that makes possible a capacitive or an inductive coupling between the electrode systems ( 2 , 3 ) on the rotor disk ( 1 ) and the stator disk ( 4 ), whereby the transmitter electrodes ( 3 ) are each supplied with an alternating voltage with different phases for neighbouring electrodes, whereby the number of supply phases, Φ, is greater than two, and the separation of transmitter electrodes=the separation of receiver electrodes/Φ, characterised in that the transmitter electrodes ( 3 ) of the stator ( 4 ) are geometrically arranged such that errors in their geometry relative to the geometry of the receiver electrodes ( 2 ) produce equal but opposite error signals in the receiver electrodes ( 2 ) of the rotor ( 1 ).