DEVICE FOR DETECTING THE ANGULAR POSITION OF A ROTARY MEMBER

摘要

A device is disclosed for the detection of the angular position of a rotary member presenting at its periphery angle marks (11), respectively teeth, at least one angle mark and/or one interval between two angle marks being distinct in order to form a reference mark (12). This may be achieved for example by providing a larger or narrower angle mark, respectively a gap, between two angle marks. The distance between two edges of angle marks is determined by a counter (17) counting the clock pulses in a continuous free-running mode. For each angle mark edge to be evaluated (leading edge or trailing edge) the instant state of the counter is transmitted to a memory (18). To recognize a reference mark, consecutive stored values are subtracted and comparisons between the corresponding consecutive differences are made. If a difference value deviates from the preceding difference value and from the following difference value by a given amount, a reference mark signal is generated.