| 摘要 |
PURPOSE:To improve conversion accuracy and to improve explosion proof property, environment resistance and the like, by coupling a controller part, which converts an input signal into a light signal, and a converter part, which feeds back an operating amount after it is converted into light, by a piece of optical fiber. CONSTITUTION:A controller part 2, which has a control and operation part 30, a light emitting part 40 and a light receiving part 50, is coupled with a converter part 3 by a piece of optical fiber 4. The converter part 3 is composed of a light to air pressure converter part 60 and an air pressure to light converter part 70. At an opening part of one end of a hollow optical fiber 61 in the converter part 60, a flapper 64 is provided. A hollow part is made to be an air path of supplied air. The inside of the wall is made to be the light path of a light signal. The change in back pressure of the supplied air due to the deformation of the flapper is taken out as the output air pressure. The light signal from the light emitting part 40 is converted into the output air pressure by the converter part 60. The pressure is used as an operating force. The operating amount is converted into light by the converter part 70. After the conversion, the amount is fed back to the light receiving part 50. The difference between a signal S2, which is proportional to the output air pressure from the converter part 3 and received by the light receiving part 50, and an input signal S1 is detected. The control operation part 30 is performed. Thus the feed-back system is constituted. |
