| 摘要 |
PURPOSE:To prevent a brush from being rotated when the driving power of an electric blower is low by triggering a bidirectional thyristor by the conductive output of a transistor. CONSTITUTION:When the potential difference of both ends of a variable resistor 1 is large, the bidirectional thyristor 6 is triggered at a late time; thereby, the driving power of the electric blower 7 is lowered. The output of a differential amplifier 9 is raised and the transistor 10 does not conduct nor the bidirectional thyristor 11 is triggered. Accordingly, even when a switch 12 is turned on, a motor 8 is not driven. That is, when the driving power of the electric blower 7 is low and the suction force of a cleaner is weak, the motor 8 for a suction equipment is not driven nor the brush is rotated. In such a way, the driving power of the electric blower 7, or the suction force of the cleaner is used with a scale below a prescribed strength, the motor 8 for the suction equipment is constantly stopped, so that at the time of cleaning a curtain or a carpet having long wool or the like, they are not wound on the brush. |
