| 摘要 |
PROBLEM TO BE SOLVED: To enable start with less overshoot by driving a motor on a first control voltage until frequency signals are counts N times (N is a natural number larger than K) and on a second control voltage thereafter. SOLUTION: A first control value NFF to be input to a PWM coverter 6 is increased from an initial value so small as not to cause start each time frequency signals (FG) are counted until a motor 1 is driven. When FG is counted K times, it is considered that the motor 1 has been started, and increasing the first control value NFF is stopped. Then the voltage value at that time is maintained. When FG is counted N times (N>K), it is considered that the frequency of FG has been stabilized, and a second control value NF corresponding to the frequency of FG is input to the converter 6 to drive the motor 1. This makes it possible to optimize the constant K and the constant N, and to make motor driving voltage at the time of start the minimum value required for start. Thus start with less overshoot is possible. |
