Patent ID: 6448725
Filing Date: 2002-09-10
Classification: H02P

Abstract:
An apparatus for detecting a rotor position in a brushless direct current (BLDC) motor comprising:a first integrator for integrating a signal input through a virtual neutral point of power supply lines of three phases connected to the BLDC motor; a second integrator for integrating a signal input to the power supply line of one phase among the power supply lines of the three phases; an operation unit for mixing a signal output from the first integrator, an operation signal of a signal output from the second integrator and a proportional coefficient R, and an operation signal of a proportional coefficient L and current of the one phase; a first comparison unit for comparing a signal of the one phase output from the operation unit with a predetermined first reference value; a second comparison unit for comparing the signal of the one phase output from the operation unit with predetermined second and third reference values; and a position signal calculator for calculating a position signal by operating signals output from the first and second comparison units.