| 摘要 |
PURPOSE: To measure the speed of a motor in a wide range by a simple algorithm, by reading measurement pulses changed in frequency in accordance with the revolution number of the motor and generating reference pulses of a frequency larger than that of the measurement pulses. CONSTITUTION: A frequency generator 20 generates a measurement signal in accordance with the rotation speed of a capstan motor 10. A measurement pulse-generating means 30 converts the measurement signal of the generator 20 into a rectangular wave and generates a measurement pulse. A reference pulse-generating means 40 generates a reference pulse of a larger frequency than that of the measurement pulse. A start signal-generating means 50 is activated by the measurement pulse, and a sampling time-setting counting means 70 sets a sampling time. An end signal-generating means 60 is started by the measurement pulse. An operation means 100 determines a rotation number of the motor according to a predetermined formula from a count of reference pulses and a count of measurement pulses measured by a reference pulse- counting means 80 and a measurement pulse-counting means 90. |
