| 摘要 |
<P>PROBLEM TO BE SOLVED: To eliminate switching of a switching element at the time of controlling speed of an electric motor, to make an operation of a driven element smooth and to control speed and a rotation direction of the electric motor by a simple control map. <P>SOLUTION: A motor controller driving the electric motor has a driving circuit having four switching elements FET1 to FET4, and the switching elements FET1 to FET4 are PWM-controlled by a microcomputer. A duty ratio x1 of the switching element FET1 is calculated by the microcomputer based on moving speed of a sliding door. A duty ratio x3 of the switching element FET3 is set to a value obtained by subtracting the duty ratio x1 of the switching element FET1 from 100%. The switching elements FET2 and FET4 are driven by inverting phases with respect to the switching elements FET1 and FET3. <P>COPYRIGHT: (C)2007,JPO&INPIT |
