Patent ID: 6710572
Filing Date: 2004-03-23
Classification: H02P

Abstract:
A drive controller for brushless motors, comprising:a multiplicity of switching means each having a first switching element connected between a first power supply providing a first potential and an output terminal of said drive controller, and a second switching element connected between said output terminal and a second power supply providing a second potential; oscillator means for generating triangular signals varying between a maximum and a minimum potential and about a mean potential; position signal generation means for generating sinusoidal position detection signals based on the signal detected by a position detector of said brushless motor, said sinusoidal position detection signals varying about a mean potential; and comparator means for comparing the magnitudes of said triangular signals with said sinusoidal position detection signals to generate PWM signals, wherein the mean potential of said triangular signals and the mean potential of said sinusoidal position detection signals are set to the same reference potential, wherein said first switching element and said second switching element of each switching means are turned ON/OFF alternately by each pulse of said PWM signals; wherein when said first switching element is turned ON/OFF by each pulse of said PWM signals, said second switching element is turned OFF/ON by each pulse of said PWM signals which is in phase with said first switching element: and wherein when said second switching element is turned ON/OFF by each pulse of said PWM signals, said first switching element is turned OFF/ON by each pulse of said PWM signals which is in phase with said second switching element.