Electronic compass

US6070333A · kind A · utility

Assignee

• Siemens Aktiengesellschaft · DE

Inventors

• Michael Kutzner · Pocking, DE
• Erich Hufgard · Regensburg, DE

Key dates

• Filing date: Jan 26, 1998
• Grant date: Jun 6, 2000
• Expiry date: Jan 26, 2018

Classification

• Technology area (CPC G): Physics
• CPC primary: G01R33/09
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

An electronic compass has a compass housing. An electronic magnetic field sensor is disposed in a fixed position relative to the compass housing. A magnet is rotatably mounted relative to the magnetic field sensor and independently aligned with a terrestrial magnetic field. The magnet has a magnetic field with a magnetic field direction and the electronic magnetic field sensor is located within a range of influence of the magnetic field. The electronic magnetic field sensor has a first magnetoresistor with a first fixed reference axis and an electric resistance of the first magnetoresistor is a function of a first angle of rotation between the fixed first reference axis and the direction of the magnetic field. The electronic magnetic field sensor defines a first differential bridge circuit and the first magnetoresistor is disposed in the first differential bridge circuit which during operation of the compass, supplies an output voltage dependent on the first angle of rotation. The first differential bridge circuit has a second magnetoresistor, and magnetizations of the first magnetoresistor and the second magnetoresistor are rotated relative to one another.