Apparatus for determining external stray magnetic fields on a magnetic field sensor
AssigneeMethode Electronics Malta Ltd.
InventorJohannes Gießibl
Life of this patent
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Abstract
An apparatus is provided for detecting an external magnetic field and/or a product-related magnetic field on a ferromagnetic component, which has a magnetization in the form of magnetic tracks. The apparatus comprises at least two magnetic field sensors which can detect an external magnetic field acting on the ferromagnetic component. Each magnetic field sensor comprises two coils, wherein each coil is assigned at least one magnetic track. Each two coils are configured so that they have a different sensitivity to one another, wherein one coil which has a higher sensitivity with respect to the other coil. The coil having the higher sensitivity ensures that the effect of an external magnetic field is amplified.
Claims19
An apparatus for detecting at least one of an external magnetic field and a product-related magnetic field on a ferromagnetic component (1, 19), wherein the ferromagnetic component (1, 19) has a magnetization from a plurality of magnetic tracks (34, 35, 36;
- 100, 110, 120), the apparatus comprising at least two magnetic field sensors (17, 18, 41, 46) being configured to detect an external magnetic field (11, 21) acting on the ferromagnetic component (1, 19), each magnetic field sensor (17, 18, 41, 46) comprising two coils (27, 28, 27′, 28′), each coil (27, 28, 27′, 28′) being assigned to at least one magnetic track (34, 35, 36, 39) with two coils (27, 28, 27′, 28′) of each magnetic field sensor (17, 18, 41, 46) being configured so that they have a different sensitivity to one another, the one coil (27, 28, 27′, 28′), having a higher sensitivity with respect to the other coil (27, 28, 27′, 28′), being arranged closer to an end of the ferromagnetic component (1, 19) than the coil (27, 28, 27′, 28′) having the lower sensitivity, such that an effect of the external magnetic field is amplified.
A method for detecting at least one of an external magnetic field and a product-related magnetic field on a ferromagnetic component (1, 19), wherein the ferromagnetic component (1, 19) has magnetization in the form of magnetic tracks (34, 35, 36;
- 100, 110, 120), the method comprising:
- arranging two magnetic field sensors (17 and 18, or 41 and 46) relative to the ferromagnetic component (1, 19) in a manner such the magnetic field sensors (17, 18, 41, 46) detect an external magnetic field (11, 21) acting on the ferromagnetic component (1, 19), wherein each magnetic field sensor (17, 18, 41, 46) comprises two coils (27, 28, 27′, 28′) and the two coils (27 and 27′, 28 and 28′) of each magnetic field sensor are configured that they have a different sensitivity with respect to one another, wherein each coil (27, 28, 27′, 28′) is assigned to at least one magnetic track (34, 35, 36;
- 100, 110, 120), wherein the coil (27′, 28′) having a higher sensitivity with respect to the other coil (27, 28, 27′, 28′) is arranged closer to the at least one end of the ferromagnetic component (1, 19) than the coil (27, 28, 27′, 28′) having the lower sensitivity such that the effect of an external magnetic field is amplified.
Dependencies are inferred from the claim text.