METHOD CHECKING THE ORIENTATION OF A MAGNETIC RING POSITION INDICATOR

摘要

A magnetic indicator ring has a set of boundaries between magnetic domains. Some or all of these are to be identified. A reference set of measurements of the angular widths between the boundaries to be identified are measured and recorded. Later a second set of measurements of the widths between those boundaries are made and these widths are matched against the reference set. Matching up widths identifies which of the boundaries are which from the reference set. This enables other data recorded respective to those boundaries to be used. For example the other date may be offsets between the boundaries and the position of a rotor in a switched reluctance motor used to drive the compressor wheel in a supercharger.

主权项

1. A method of identifying, for a magnetic ring indicator having a set of boundaries between sectors of different magnetisation, the boundaries of a plurality of the boundaries of the set, comprising:
providing in a control circuit, for the plurality of the boundaries, a first plurality of measurements of the angular widths between the neighbouring ones of the boundaries of the plurality; rotating the magnetic ring indicator so that a sensor indicates to the control circuit the occurrence of the boundaries of the plurality at the sensor; the control circuit calculating from the indicated occurrences of boundaries a second plurality of measurements of the angular widths between the neighbouring ones of the boundaries of the plurality; and matching the angular widths of the first plurality to the angular widths of the second plurality to provide an indication of the match.