| 摘要 |
PURPOSE:To detect the application of abnormal external forces on a motor shaft and to control the motor by performing logical judgement of the magnitude and direction of the current of a DC motor and the magnitude and the direction of the differentiated value of a speed signal. CONSTITUTION:A reference signal I0 is given to one terminal of a comparator 4 and one terminal of a comparator 6, and a motor-current signal 1 is applied to the other terminals of the comparators. Each output signal of the comparators are applied to one terminal of an AND gate 8 and one terminal of an AND gate 10. A rotating speed V of the motor is supplied to a differentiator 16, and its output accerelation- speed signal 2 is applied to a positive coding circuit 18 and negative coding circuit 20. The output signals from said coding circuits are applied to the other terminals of the AND gates 8 and 10. Therefore, the AND gate 8 sends out a logic ''1'', when the motor current I is larger than I0 and the acceration 2 is negative; and sends out a ''0'' in the other case. The AND gate 10 performs the same logical judgment, thereby the specified logic output is obtained. When the output of an OR gate 12 is a logic ''1'', abnormal-collision condition is indicated. |
