MAGNETIC SENSOR

• Main Authors: KAWAI HISASHI, SHIRATANI KAZUHIKO, TAKIMOTO TOSHIYUKI, MIZUTANI AKITOSHI
• Format: Patent
• Language: English
• Published: 18.12.2002
• Edition: 7
• Subjects: ACTUATING-FLOATS; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVEREDIN A SINGLE OTHER SUBCLASS; BLASTING; COCKS; DEVICES FOR VENTING OR AERATING; ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVEFUNCTIONING OF MACHINES OR INSTALLATIONS; HEATING; LIGHTING; MEASURING; MEASURING ANGLES; MEASURING AREAS; MEASURING ELECTRIC VARIABLES; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS; MEASURING LENGTH, THICKNESS OR SIMILAR LINEARDIMENSIONS; MEASURING MAGNETIC VARIABLES; MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR; MECHANICAL ENGINEERING; PHYSICS; TAPS; TARIFF METERING APPARATUS; TESTING; THERMAL INSULATION IN GENERAL; VALVES; WEAPONS

PROBLEM TO BE SOLVED: To improve the detection sensitivity of a magnetic sensor. SOLUTION: For the magnetic sensor, a detection coil 2 for sending an alternating current to a primary coil 22 and outputting a voltage induced in a secondary coil 23 is provided and the induced voltage is made in accordance with the progression of a core 5 by changing a magnetic flux according to the progression of the core 5 into the detection coil 2. In a shield case 3 constituted of a conductive magnetic material surrounding the detection coil 2, a slit 301 is formed to the direction of the magnetic flux, that is, the direction parallel to the axial line of the detection coil 2. The path of eddy current flowing in the shield case 3 along the surface vertical to the direction of the magnetic flux is cut finely with the slit 301 to reduce an eddy current loss.