| 摘要 |
PURPOSE:To stably control a motor by providing a digital-to-analog converter in a period-to-voltage converter and moving the operating point in response to the variation in the reference frequency, thereby eliminating the variation in the phase synchronization point. CONSTITUTION:A speed signal detected by a frequency generator 2 and the signal of a variable frequency reference frequency generator 11 are applied to a phase comparator 12, one speed signal is applied to a pulse generator 5, a timer 6, a counter 7 and a period-to-voltage converter 4 including a D/A converter 10, both the output signals are added, and the energization of a motor 1 is controlled by the error signal with a reference voltage generator 15. The setting time of the timer 6 is varied to displace the operating point of the converter 10 from the center slightly to the upper side, thereby correcting the error in the linearity. Accordingly, the motor can be stably controlled without variation in the phase synchronizing point even for the variation in the reference frequency. |
