| 摘要 |
PURPOSE:To drive a stepping motor speedily by driving it with an external driving pulse when an internal oscillation pulse matches the external driving pulse and then with the internal oscillation frequency when the external driving pulse becomes small. CONSTITUTION:When an external driving pulse is input from a terminal IN1, a Q terminal is set to an 'H' level. Oscillation starts at a frequency where an internal oscillation circuit 5 gradually starts up and the oscillation signal is fed to an input B terminal of a speed comparison circuit 7, and then is fed to a distributor 15, thus enabiling a stepping motor 15 to gradually increase a rotational speed. In this case, the external driving pulse and the internal oscillation pulse are compared by the speed comparator 7, an output terminal OUT1 is changed to the 'H' level when they match, and then an 'L' level signal is fed to one of input terminals of an AND gate 10, thus completing the throw-up operation period and driving the motor at a constant high speed by the external driving pulse. After that, the speed is reduced gradually when the internal oscillation pulse exceeds the external driving pulse. |
