| 摘要 |
<P>PROBLEM TO BE SOLVED: To smooth a current supplied from power supply, and to further reduce the frequency where the larger current is supplied from the power supply, even in case where two motors are driven independently such as in positioning control. <P>SOLUTION: A first PWM control signal generating portion 36, and a second PWM control signal generating portion 37 generate a first and a second PWM control signals, based on sawtooth wave carriers C, D whose phase difference is 1/2 wavelength. These two DC motors are made to operate with the first and the second PWM control signals, by which since the timing of the current inflow to the two DC motors from the power supply will not overlap, as long as one of duty ratios does not exceed 50%, even in case where the both duty ratios change at each moment, the current supplied from the power supply is smoothed, and the frequency where the larger current is supplied from the power supply is reduced significantly. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
