Position indicator

US5585924A · kind A · utility

Assignee

• VDO Adolf Schindling AG · DE

Inventors

• Erwin Schneider · Fulda, DE
• Frank Gohring · Frankfurt, DE
• Harald Frey · Pocking, DE

Key dates

• Filing date: Mar 9, 1995
• Grant date: Dec 17, 1996
• Expiry date: Mar 9, 2015

Classification

• Technology area (CPC G): Physics
• CPC primary: G01D5/244
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

A device for producing an electric signal which corresponds to the position of an object which is movable in translation or rotation relative to a base, wherein by optical scanning of markings which periodically recur upon a movement of the object, analog voltage signals A, A and B, B are produced by means of sensors which are spaced apart from each other by one-quarter of the scanning period. The signals are converted in an evaluation circuit with comparators into digital forms of the signals A and B (quadrature signal). In order to produce a test signal S, there is also provided in the device a summation circuit by means of which the voltage signals A, A and B, B are added and compared in a comparator with a threshold value.