DEVICE FOR MEASURING MAGNETIC FIELDS

摘要

The device comprises a magnetic field sensor (1) with a number of magnetoresistive sensor elements (3) which are situated in one plane and which have the same privileged directions of magnetization. In the vicinity of the magnetic field sensor (1), there is arranged a magnetization coil (13) which is connected to a current pulse generator (15) which is arranged to supply the magnetization coil with current pulses of opposite current direction in an alternating fashion in order to generate a magnetic field in the magnetization coil which extends parallel to the privileged directions of the sensor elements and is strong enough to reverse the direction of the internal magnetization of the sensor elements. In order to minimize the dimensions and the weight of the sensor part of the device, the magnetization coil (13) comprises a substrate (19) which is made of an electrically insulating material and on which there is provided an approximately spiral-shaped electric conductor track (21) which comprises a group of active conductor elements (23) which is formed by a number of parts of the conductor track which extend in parallel on a surface of the substrate, an electric current (25) flowing through the conductor track having the same direction in all active conductor elements of the relevant group. The magnetic field sensor (1) is mounted on the substrate (19) in the immediate vicinity of the group of active conductor elements (23) in such a position that the plane of the sensor elements (3) extends substantially parallel to the plane of the active conductor elements, and the privileged direction of magnetization of the sensor elements extends perpendicularly to the longitudinal direction of the active conductor elements.