Patent ID: 10439525

Abstract:
A motor drive device includes a detecting unit that detects a rotational position of a rotor, a drive waveform generating circuit that generates a drive waveform, a control unit that synchronizes a phase of the rotational position of the rotor and a phase of the drive waveform, and a phase difference setting unit that sets a phase difference between the rotational position and the drive waveform during synchronization. An Apos generating unit calculates and outputs a position count proportional to a rotation amount of the rotor. A Bpos generating unit acquires the position count from the Apos generating unit and converts the count into a count value with the upper limit value as the maximum value. A Cpos generating unit multiplies the count value acquired from the Bpos generating unit by the conversion ratio, and calculates a count value with a predetermined upper limit value as the maximum value.