| 摘要 |
An electric vacuum cleaner which can detect the occurrence of a spark by an inexpensive structure and prevents smoking and ignition due to abnormal overheat in an end stage of life. The electric vacuum cleaner comprises a motor (7) having a commutator (11f) and a brush (11j), a current detecting portion (3a) for detecting a current in the motor (7), a rectifying portion (3b) for rectifying the output of the current detecting portion (3a), an A/D converting portion (3c) for sampling the output of the rectifying portion (3b) as a digital value, a spark judging portion (4) which determines that a spark occurring in the motor (7) is abnormal when the sampled digital value exceeds a predetermined criterion level, and a driving means (5) which cuts off the supply of power to the motor (7) to stop the operation thereof when the spark occurring in the motor is judged abnormal by the spark judging means (4). |
