CONSIDERATION OF MAGNETIZATION AND DETECTION ON MAGNETIC ROTARY ENCODER USING FINITE-ELEMENT METHOD

This article shows the results of a feasibility study of a high resolu tion magnetic rotary encoder, The magnetization and the detection proc esses of a magnetic rotary encoder were simulated using a finite eleme nt method, In addition, experimental consideration have been given to the numerical effect of the parameters on a magneto-resistive output b y a method of a double interpolation. The optimum condition of a Z pha se(i,e,, original point of the rotation) signal obtained for the magne to-resistive output was a magnetization gap 0 mu m and a magnetization current of 400 mA(i,e., the magnetized state for saturation of the me dium), It was analytically determined that an increase in magnetizatio n current or a detection gap decrease saturated the magnetoresistive o utput voltage, The magneto-resistive output obtained by using a finite element method showed good numerical agreement with the experimental results given conditions when the magnetization current was 200 mA or less, It was an advantage therefore, in the case of the minimum MR ele ment being used with a double interpolation method, to achieve a wider usable detection gap range.