| 摘要 |
PROBLEM TO BE SOLVED: To obtain a blower fan motor which is driven by a brushless motor and has an automatic restoring function, where the fan motor is controlled so as to discontinue the current application to the winding of the motor for deceleration, when the number of revolutions of the motor exceeds a reference number of revolutions, and to restart the current application to restore the normal rotation, when the revolution is below the reference revolution. SOLUTION: A voltage proportional to a revolution is outputted by an output signal of a Hall device and is compared with a reference voltage by a comparison circuit. If the voltage is higher than the reference voltage, the current application is discontinued for deceleration, and if the rotational speed falls to below the reference speed, the current application is restarted to restore normal operation automatically. |
