US 12,282,046 B2
Magnetic field sensor for measuring a direct current
Christian Kern, Kaysersberg Vignoble (FR)
Assigned to SOCOMEC, Benfeld (FR)
Appl. No. 18/727,880
Filed by SOCOMEC, Benfeld (FR)
PCT Filed Dec. 13, 2022, PCT No. PCT/EP2022/085493
§ 371(c)(1), (2) Date Jul. 10, 2024,
PCT Pub. No. WO2023/174572, PCT Pub. Date Sep. 21, 2023.
Claims priority of application No. 2202411 (FR), filed on Mar. 18, 2022.
Prior Publication US 2025/0102544 A1, Mar. 27, 2025
Int. Cl. G01R 15/18 (2006.01); G01R 19/00 (2006.01)
CPC G01R 15/185 (2013.01) [G01R 19/0092 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A magnetic field sensor for measuring a direct current, formed of at least one superparamagnetic material transducer, adapted to be subjected to an external magnetic field to be measured, and electrically coupled to an excitation module and to an analysis module, wherein:
the transducer comprises at least one pair of coils with superparamagnetic core, the superparamagnetic coils being substantially identical and being connected in series between two extreme terminals of the transducer, a common connection point of the superparamagnetic coils being connected to a reference potential;
the excitation module is configured to generate and inject an excitation current into the transducer, at a predefined excitation frequency, and comprises at least:
one midpoint coil mounted in parallel to terminals of the transducer;
one excitation voltage generator mounted between the reference potential and said midpoint; and
one excitation impedance configured to form with the superparamagnetic coils a first series RLC-type circuit with a resonance frequency substantially equal to the excitation frequency;
the analysis module comprising at least:
one analysis impedance connected to external terminals of the midpoint coil, the analysis impedance being configured to form with the superparamagnetic coils a second series RLC-type circuit with an analysis resonance frequency substantially equal to an analysis frequency; and
one analyzer that analyzes the current passing through the analysis impedance at the analysis frequency to extract a component at said analysis frequency equal to an even multiple of the excitation frequency.