Position sensor employing a soft magnetic core

US5204621A · kind A · utility

Assignee

• Papst Motoren GmbH & Co KG · DE

Inventors

• Michael Hermann · Tacherting, DE
• Johann von der Heide · Winterthur, CH
• Hans Dieter Papst · St. Georgen, DE
• Uwe Mueller · Cleebronn, DE

Key dates

• Filing date: Feb 7, 1991
• Grant date: Apr 20, 1993
• Expiry date: Feb 7, 2011

Classification

• Technology area (CPC G): Physics
• CPC primary: G01D5/225
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

A position sensor using a soft magnetic core and a permanent magnet for detecting linear or rotary movements of a part. In one embodiment, a differential transformer is provided with corresponding windings 3, 4 and 5, which are wound on a tubular carrier member 2. Provided inside the carrier member 2 are a saturatable core 6 with a V-shaped crosssection section and a control magnet 8 which slides on the inner surfaces. The core 6 is partially saturated on the contact surfaces, so that a virtual air gap is produced, so that the transformation ratio between the windings 3 and 4, 5 is controlled as a function of position. Other versions employ flat and/or meandering coil arrangements and, in two instances, rotational relative motion.