| 摘要 |
PURPOSE:To make noise form a ventilating fan low, by preventing current wave forms from pulsating when the number of revolution of a capacitor induction motor is changed, by providing a plurality of capacitors of which capacitances are different from each other on the side of a power source, and by selecting one of the capacitors by selectively changing the capacitors. CONSTITUTION:A plurality of capacitors 6 and 7 of which capacitances are different from each other are provided in parallel between a capacitor induction motor 1, which drives a ventilating fan for gas range, and an electric power source 5. The capacitors 6 and 7 can selectively be selected and be contacted to the therminals 9 and 10 of a changing switch 8. When the changing switch 8 is thrown into the terminal 9 or 10 to drive the motor at medium speed or at low speed, sinusoidal waves are formed in any case as well as is the case that the switch is thrown into the terminal 13. As a result low noise and stabilized operational characteristics can be obtained in the capacitor induction motor 1.
|
