| 摘要 |
A differential transformer type magnetic sensor (3, 3a, 3b, 3c) includes a first coil layer (21, 21a, 21b), a second coil layer (23, 23a, 23b), and an insulating layer (25) formed between the first coil layer (21, 21a, 21b) and the second coil layer (23, 23a, 23b). The first coil layer (21, 21a, 21b) includes a detection coil (4) formed of a planospiral first wire (4a) located on a plane and a first drive coil (5) formed of a planospiral second wire (5a) running in parallel to the first wire (4a) on the same plane as the first wire (4a). The second coil layer (23, 23a, 23b) includes a reference coil (6) formed of a planospiral third wire (6a) located on a plane and a second drive coil (7) formed of a planospiral fourth wire (7a) running in parallel to the third wire (6a) on the same plane as the third wire (6a). The first drive coil (5) and the second drive coil (7) are electrically connected together so that a direction of drive current flowing in the first drive coil (5) is the same as a direction of drive current flowing in the second drive coil (7). The detection coil (4) and the reference coil (6) are electrically connected together so that a direction of induced current flowing in the detection coil (4) is reverse to a direction of induced current flowing in the reference coil (6). |
