| 摘要 |
PURPOSE:To remove the turbulence of magnetism due to the body of an automobile and the like and to enable thereby precise measurement of the direction of advance thereof, by adding a simple primary coordinate conversion circuit to a magnetic compass containing a magnetic sensor. CONSTITUTION:Out of two output axes 1X and 1Y of the magnetic sensor in the magnetic compass mounted on an automobile and the like, the reference output axis 1Y is arranged in such a manner that it accords with the axis of the direction of running of the automobile. Outputs Ex and Ey from these axes are given to a coordinate conversion circuit consisting of resistors 500-503 and an operational amplifier 40 and to another coordinate conversion circuit consisting of resistors 504-507 and an operational amplifier 50, wherefrom outputs Ex' and Ey' are delivered respectively. The resistors 500-507 are set in a prescribed value at which the effect of a magnetic field caused by magnetization of the body is canceled. Through detection and operation of Ex' and Ey', the turbulence of the magnetism of the vehicle body is removed and thus the direction of advance thereof is measured precisely. |
