| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a satellite broadcast receiver capable of controlling the elevation angle of an antenna in simple mechanism. SOLUTION: When the power source of the receiver is turned on, a driving motor starts rotating forward, a slide pin moves downward, the offset control of an input voltage is performed for stabilizing a detection circuit during that movement, and the elevation angle of the antenna is enlarged. At such a time, a voltage is stored in the detection circuit. Further, when the driving motor is rotated backward, the slide pin moves upward and the elevation angle is reduced. In this case, the voltage compared with the stored voltage in a comparator circuit and the higher voltage is selected. The driving motor is rotated to provide the selected elevation angle and elevation angle control is completed. Further, the driving motor is continuously rotated, the present voltage is compared with the stored maximum voltage. When the voltage is equal with the maximum voltage or reaches an allowable range, the driving motor is stopped and azimuth angle control is completed.</p> |
