| 摘要 |
PURPOSE:To ensure a detection of direction with a high precision, by using the wing part of a magnetic substance constituting a detection part of earth magnetism alos for an optical shutter. CONSTITUTION:Two coils 4 and 18 are provided coaxially to a rotaing shaft 1 and with the same winding specifications and then connected in series so that the winding directions of them become opposite to each other. At the same time, a magnetic substance 2 is provided coaxially to the shaft 1 and piercing through the coils 3 and 18, and wing parts 15, 16 and 18 of magnetic substance are fixed at both ends and the middle part of the substance 2 with no contact to the coils. The wing parts 15 and 18 are opposite to the part 16. When the shaft 1 is turned to rotate the wing parts 15, 16 and 18, the changes of magnetic flux arise to the coils 4 and 18 in the opposite direction to each other. Then the sum of the electromotive power is obtained across the coil in case when the coils 4 and 18 are connected in series since the winding directions of coils are opposite to each other. |
