JPS5786712A - Magnetic azimuth sensor - Google Patents

Abstract

PURPOSE:To ensure the sensing of the azimuth by applying an AC whose magnitude is large enough to saturate an annular magnetic core, and applying DC to a winding which generates biased magnetic fields, in addition to output windings which sense external magnetic fields and the magnetic flux of an exciting winding. CONSTITUTION:The AC whose magnitude is large enough so as to saturate the magnetic core 2 is applied to the exciting winding 3 which is wound around the annular magnetic core. The output windings 4 and 5 which sense the external magnetic fields and the magnetic flux of the exciting winding are provided so as to encircle the part facing the exciting winding 3 at a ring angle. The bias coil 6 is provided so as to form 45 deg. with the output windings 4 and 5 and the DC is flowed. The DC biased magnetic field having a sufficiently large magnetic force in comparison with geomagnetism is given to the output windings 4 and 5. The magnitudes of te outputs from the output windings 4 and 5 due to the geomagnetism varies with the azimuth of the windings but their polarities are not reversed. Therefore, the processing at the later stage is simplified and the affects of the external electromagnetic wave are reduced. In this constitution, the judgement of the polarity is unnecessary, signal processing becomes easy, and the detection of the azimuth is ensured.