| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a motor drive controller that can limit a current properly even if revolutions are fluctuated without causing cost increase by the use of a device like a current detection means. <P>SOLUTION: The motor drive controller for a rotary motor rotates a rotor by making a current flow periodically in armature windings having a plurality of phases according to the rotational position of the rotor. The controller comprises: a speed detection means, which detects the rotational speed of the rotary motor; a voltage limitation means, which limits a voltage supplied to the windings to the specified limit voltage or lower; and a limit voltage determination means, which outputs the limit voltage according to the rotational speed. The limit voltage determination means is configured to: calculate the limit voltage by making it larger than the relation calculated from a counter electromotive voltage of the rotary motor proportional to the rotational speed, the resistance of the windings and a prescribed target limit current; and enlarge the increase ratio as the rotational speed becomes larger. <P>COPYRIGHT: (C)2009,JPO&INPIT |
