| 摘要 |
PURPOSE:To maintain a brush without a large quantity of time by electrically detecting the wear state of the brush. CONSTITUTION:A light signal is interrupted by a brush 1 in the state that a brush 1 is not worn, and a light is not communicated between a transmitter 7 and a receiver 8. When the brush 1 is worn, the interrupted state of the light signal is released, the light signal is communicated between the transmitter 7 and the receiver 8, an alarm unit such as a buzzer or a lamp is operated to discriminate that the brush 1 reaches the wear limit. |
