Apparatus and method for measuring magnetic fields

Patent metadata

Field	Value
Publication number	US-9316703-B2
Application number	US-201214005983-A
Country	US
Kind code	B2
Filing date	Feb 23, 2012
Priority date	Mar 18, 2011
Publication date	Apr 19, 2016
Grant date	Apr 19, 2016

Abstract

An apparatus for measuring a magnetic field is described, which comprises a core and an exciter coil for remagnetizing the core material. The remagnetizable core material is embodied as a layer or as multiple layers disposed at a distance from one another, and the core has a maximum total extension G where 2.5 mm≧G≧0.2 mm, a ratio of length to width that is greater than or equal to a value of twenty, and a thickness D where 2 μm≧D≧0.2 μm. Also described is a corresponding method for measuring a magnetic field.

First claim

What is claimed is:

1. An apparatus for measuring a magnetic field, comprising:
a core including a remagnetizable core material and an exciter coil for remagnetizing the remagnetizable core material, wherein:
the remagnetizable core material includes multiple layers of the remagnetizable core material disposed at a distance from one another;
a ratio of length to width of the core is greater than or equal to a value of twenty;
a thickness of the core is D;
2 μm≧D≧0.2 μm;
a thickness of each individual one of the layers is D S ; and
60 nm≧D S ≧20 nm.

2. The apparatus as recited in claim 1 , wherein the remagnetizable core material has a permeability index greater than or equal to two thousand.

3. The apparatus as recited in claim 1 , wherein the remagnetizable core material has a permeability index greater than or equal to ten thousand.

4. The apparatus as recited in claim 1 , wherein the remagnetizable core material is a soft magnetic material.

5. The apparatus as recited in claim 1 , wherein the remagnetizable core material is a nickel-iron alloy.

6. The apparatus as recited in claim 1 , further comprising:
a plurality of non-magnetic intermediate layers, each non-magnetic intermediate layer being respectively disposed between respective pairs of the layers of the remagnetizable core material.

7. The apparatus as recited in claim 1 , further comprising:
a device for detecting a remagnetization process.

8. The apparatus as recited in claim 1 , wherein a maximum total extension of the core is G, and 2.5 mm≧G≧0.2 mm.

9. A microelectromechanical system, comprising:
an apparatus for measuring a magnetic field, the apparatus comprising a core that includes a remagnetizable core material and an exciter coil for remagnetizing the remagnetizable core material, wherein:
the remagnetizable core material includes multiple layers of the remagnetizable core material disposed at a distance from one another;
a ratio of length to width of the core is greater than or equal to a value of twenty;
a thickness of the core is D;
2 μm≧D≧0.2 μm;
a thickness of each individual one of the layers is D S ; and
60 nm≧D S ≧20 nm.

10. The system as recited in claim 9 , wherein a maximum total extension of the core is G, and 2.5 mm≧G≧0.2 mm.

11. A method for measuring a magnetic field using an apparatus that includes a core, wherein the core includes a remagnetizable core material and an exciter coil for remagnetizing the remagnetizable core material, the remagnetizable core material includes multiple layers of the remagnetizable core material disposed at a distance from one another, a ratio of length to width of the core is greater than or equal to a value of twenty, a thickness of the core is D, 2 μm≧D≧0.2 μm, a thickness of each individual one of the layers is D S , and 60 nm≧D S ≧20 nm, the method comprising:
providing an alternating current flowing through the exciter coil for a periodic remagnetization of the remagnetizable core material accompanied by formation of a periodically changing magnetic field;
superimposing a magnetic field to be measured and the magnetic field of the exciter coil; and
deducing the magnetic field to be measured from a time shift of a remagnetization of the remagnetizable core material with respect to a zero crossing of the alternating current.

12. The method as recited in claim 11 , wherein the apparatus includes a device for detecting the remagnetization process.

13. The method as recited in claim 12 , wherein the device includes a measurement coil for measuring a magnetic field change brought about by the remagnetizable core material, a point in time of remagnetization being determined by a voltage change induced in the measurement coil.

14. The method as recited in claim 13 , wherein the voltage change includes a voltage pulse.

15. The method as recited in claim 11 , wherein a maximum total extension of the core is G, and 2.5 mm≧G≧0.2 mm.

Assignees

• Schatz Frank
• Farber Paul
• Weiss Stefan
• Lammel Gerhard
• Bennini Fouad
• Bosch Gmbh Robert

Inventors

• Schatz Frank
• Farber Paul
• Weiss Stefan
• Lammel Gerhard
• Bennini Fouad

Classifications

• G01R33/18

  Measuring magnetostrictive properties · CPC title

• G01R33/05 Primary

  in thin-film element · CPC title

• G01R33/02 Primary

  Measuring direction or magnitude of magnetic fields or magnetic flux (G01R33/20 takes precedence) · CPC title

• G01R15/148 Primary

  involving the measuring of a magnetic field or electric field (G01R15/18, G01R15/20, G01R15/24, G01R15/26 take precedence) · CPC title

• G01R33/04

  using the flux-gate principle · CPC title