Patent ID: 6721385
Filing Date: 2004-04-13
Classification: G01D,G01P

Abstract:
A revolution counter for determining a number of revolutions of a rotary element, comprising:a sensor arrangement having a single sensor, and an evaluation circuit placed downstream of the sensor, said sensor scanning the rotary element and generating a raw signal commensurate with a rotary position of the rotary element for ascertaining one of at least three areas of angular ranges, wherein a first area and a second area of the at least three areas of angular ranges each include a single continuous angular range and a third area of the at least three areas of angular ranges includes at least two angular ranges which interrelate but are separated from one another; and a power generation system constructed to deliver energy pulses to the sensor arrangement, when the rotary element rotates below a minimum rotation speed, wherein the sensor arrangement generates the raw signal commensurate with a determination of the corresponding one of the areas of angular ranges, wherein the power generation system and the rotary element are so coupled to one another as to ascertain for at least part of the first, second and third areas of angular ranges as determined during output of the energy pulses, by which one of the angular ranges the rotary element is rotated, and to establish the number of revolutions based on the ascertained angular ranges.