| 摘要 |
PURPOSE: To eliminate malfunctions of a window control, by obtaining a decelerating speed on the basis of signals from a motor revolution-detecting circuit and stopping the motor when the figure is faster than a specified one. CONSTITUTION: An UP-switch 12 is pushed to output an instruction for raising a window and rotate a motor 16 and the revolution pulse signal of a revolution sensor attached to the rotary shaft is measured to calculate the revolutional speed from the pulse frequency. And on the basis of the result, the variation ratio of the revolutional speed is calculated. When it is the same with a specified threshold or larger than it, it is judged that a large deceleration has been done and the driving motor of window is suspended as the uppermost position at that time. When it is lower than the threshold, it is judged that it should be raised still more and the window is raised continuously. By repetition of the judging operation, the upper end position can be detected without much difference from the case of the actual threshold. And hence, the motor 16 is not loaded with an excessive force. The detection of the lower end position is done likewise with the detection of the upper end position. |
