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US 2003/0197483 A1Published application
Speed control circuit for a dc brushless motor
AssigneeSunonwealth Electric Machine Industry Co., Ltd.
InventorsAlex Horng, Ying-Ya Lu
Life of this patent
Estimating the term…
Abstract
The speed control circuit in accordance with the present invention mainly includes a switch circuit and a voltage-detection circuit. The voltage-detection circuit is actuated depending upon high or low voltage of power supply to thereby determine the switch circuit to output high or low operating voltage to a driver circuit of the motor in response to changes of the voltage of the power supply. The motor is adjusted and operated at desired speeds by a rated range of input voltage according to the high or low operating voltage.
Claims8
A speed control circuit for a dc brushless motor comprising:
- a switch circuit being adapted to output a high or low operating voltage to a driver circuit of the motor from a power supply;
- and
- a voltage-detection circuit being adapted to control the switch circuit to switch outputting the high or low operating voltage in response to changes of a voltage of the power supply;
- wherein when the voltage-detection circuit senses a high voltage of the power supply, the switch circuit is actuated to output the high operating voltage to the driver circuit and thus the motor is operated at a high speed;
- and wherein when the voltage-detection circuit senses a low voltage of the power supply, the switch circuit is actuated to output the low operating voltage to the driver circuit and thus the motor is operated at a low speed.
2 more elements
Dependencies are inferred from the claim text.