BIAS MAGNETIC EFFECT USING COMPOUND MAGNETIC WIRE SENSOR IN AC MAGNETIC-FIELD

A magnetic sensor which consists of a compound magnetic wire and searc h coil has a novel performance to induce the detection voltage indepen dent of changing rate of AC external field frequency in every one cycl e. The detection voltage is changed by the previous magnetized state o f the compound magnetic wire. This paper reports the effect of a DC bi as magnetic field which is applied with an AC magnetic field to make a n asymmetric field. To make a compound wire a previous magnetized stat e, the demagnetized wire is magnetized by various orienting DC field H -0. When 3 symmetric AC field Hex and DC bias field Hb are applied to the wire, the wire is magnetized by an asymmetric magnetic field, whic h consists of a reset field Hr=Hex+Hb and a set field Hs=Hex-Hb. Accor ding to the relationship among the critical field Hp, H-0 and Hb, Hp i s independent of the previous magnetized state of wire at Hb of 25 Oe or larger, and the pulse voltage is always induced at a fixed Hp. This phenomenon is very stable and reproducible.