GEOMAGNETIC SENSOR

PROBLEM TO BE SOLVED: To provide low power consumption.SOLUTION: A geomagnetic sensor includes a core 10 constituting a closed magnetic circuit, a pair of coils 21, 22 wound at positions facing each other in the core 10 and connected with each other in series so as to make the core 10 generate a magnetic flux in the same revolving direction, an excitation power source 30 for applying an AC current overlapping a DC current to the pair of coils 21, 22, and a detection circuit 40 connected to a connection point P of the pair of coils. Consequently, it is unnecessary to excite a core up to magnetic saturation as in the conventional flux gate type geomagnetic sensor.