| 摘要 |
PROBLEM TO BE SOLVED: To provide a roller with a built-in motor rotated by a brushless motor and stopped by an electromagnetic brake with a largest possible brake force by minimizing the heating of the electromagnetic coil operated to release the brake force during operation. SOLUTION: A fixed voltage is supplied to the electromagnetic coil simultaneously with the current carrying to the brushless motor to release the electromagnetic brake. The rotation of the brushless motor is detected, and when it is a fixed rotating speed or more, the current carrying to the electromagnetic coil is transferred to a current-carrying state of repeating ON/OFF in a short time to keep the release of the electromagnetic brake. The current-carrying state of repeating ON/OFF to the electromagnetic coil is set, whereby the average voltage can be suppressed low to minimize the heating. |
