Opto-electronic bachometer and position detector of an electric motor

US5021735A · kind A · utility

Assignee

• Heidelberger Druckmaschinen AG · DE

Inventors

• Jurgen Maass · Wiesloch, DE
• Helmut Meyer · Hilden, DE

Key dates

• Filing date: Jan 10, 1990
• Grant date: Jun 4, 1991
• Expiry date: Jan 10, 2010

Classification

• Technology area (CPC H): Electricity
• CPC primary: H02P6/17
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

A device for determining the rotational speed and position of a rotor of an electric motor having at least one signal track arranged on the rotor includes at least one sensor located at a stator-side of the electric motor for scanning the signal track, and an evaluation circuit connected to the sensor, the sensor being sensitive to given stimuli of the signal track for alternatively adopting one of three different states which individually produce levels of different magnitude; the evaluation circuit including detectors responsive in accordance with the levels, for cutting off levels of given magnitude so that a recognition of the rotor position is derivable from a first and a second one of the three states, and the rotational speed is derivable from the third one of the three states.