| 摘要 |
A vacuum cleaner includes a variable speed suction motor and an illuminatable motor speed indicator having plural lights arranged in a circular pattern or annular ring pattern, for example around a motor speed control switch. A control unit includes an indicator controller and a motor controller that respectively control the illuminatable indicator and the motor, based on inputs from the motor speed control switch and optionally at least one sensor that senses operating conditions of the vacuum cleaner. The lights are successively activated and deactivated to create a visible light spot that appears to rotate around the circular or annular ring pattern at a light rotation rate related to and indicative of the motor rotation speed. Thereby the indicator allows the vacuum suction power to be visually monitored. |
