PROBLEM TO BE SOLVED: To provide a high sensitivity magnetic sensor which is small and low cost and superior in linearity and temperature characteristic and its drive circuit. ;SOLUTION: A magnetic sensor is provided with an oscillation circuit 21 impressing sine wave current at the both ends of the magnetic core of a thin film magnetic impedance element 22, a buffer circuit 23 installed in between the oscillation circuit 21 and the magnetic core of the thin film magnetic impedance element 22 and controlling the mismatch of output impedance of the oscillation circuit 21 and input impedance of the thin film magnetic impedance element 22 and a detection circuit 29 detecting the magnetism variation of external magnetic field from the variation of high frequency current varying in accordance with the external magnetic field impressed to the magnetic impedance element 22.;COPYRIGHT: (C)2000,JPO
展开▼
