ROTOR POSITION DETECTION CIRCUIT, MOTOR DRIVE DEVICE AND ROTOR POSITION DETECTION METHOD

摘要

PROBLEM TO BE SOLVED: To provide a rotor position detection circuit that eliminates a defect from a conventional position sensorless drive method.

SOLUTION: A position detection circuit 23 of a motor drive device 21 outputs a first rotary position signal after a first position estimation circuit 27 compares a detection signal of phase voltage with the reference voltage (output signal of low-pass filter 10). A control part 22 produces a second rotary position signal by digitally processing the output signal of a comparator 12 in a second position estimation circuit 29 that directly compares the phase voltage with the reference voltage and compensates the rotary position indicated by the first rotary position signal with the second rotary position signal.

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