Patent ID: 8596420

Claim:
An elevator system, comprising: an elevator car; an elevator control unit; an electric drive comprising an electric machine and a frequency converter for producing a variable-amplitude and variable-frequency supply voltage for controlling the electric machine; and a measuring arrangement fitted to the electric machine for measuring an absolute position of a rotor of the electric machine, the measuring arrangement comprising: a magnetic band, the magnetic property of said magnetic band being so implemented that the magnetic property varies in a longitudinal direction of the band substantially sinusoidally, wherein the magnetic band is attached to a rotating part of the electric machine, such that the magnetic band is fitted to revolve about a rotational axis of the rotor; and a reader configured to sense the magnetic property varying sinusoidally in the longitudinal direction of the magnetic band, said reader being mounted on a stationary part of the electric machine in the immediate vicinity of the magnetic band, wherein the elevator control unit is arranged to determine the position of the elevator car in the elevator shaft by using the data detected by the magnetic band reader.