| 摘要 |
PURPOSE:To keep rotational frequency of an antenna constant for a long period of time, by using a clock device, an antenna angle position detector, and a time collating circuit which collates an angle position with time at every 1 rotation of the antenna and outputs a difference of an ideal angle and an actual angle. CONSTITUTION:From a clock device 10, a time signal is inputted to a time collating circuit 9. In this circuit 9, when rotation of an antenna 1 enters into the N-1-th rotation, an actual angle of the antenna 1 is collated with time, and rotational frequency per unit time outputs a difference of an essntial ideal angle and an actual angle. A variable voltage generator 8 selectively outputs prescribed voltage in accordance with this difference, and simultaneously, a rotation control changeover switch 7 switches adjusting voltage inputted to an amplifier 3 to an output of the variable voltage generator 8 from an output of a speed adjusting variable resistance 4. In accordance with said switching, the antenna 1 is rotated at a proper speed. This voltage is generated in accordance with a difference of an actual angle and an ideal angle, and is selected so that an ideal time is obtained when the antenna 1 enters into the N-th rotation. |
