Motor drive apparatus
AssigneeRenesas Technology Corp.
InventorsSatoshi NARUMI, Masaaki Kato, Masaharu Hoashi, Toshiya Suzuki
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Abstract
The present invention provides a motor drive apparatus which improves a trade-off relation between a stable position detection and noise at its driving. A sensorless drive operation circuit calculates by operation a zero cross point (point p) of a voltage of a position detection phase at the next interval, using time information measured based on an output signal from a comparison circuit at the previous interval and the present interval. After the point p has been calculated, points a and b are detected by interrupting a predetermined time drive current.
Claims7
A motor drive apparatus for driving a 3-phase brushless motor without using a Hall sensor, comprising:
- a voltage comparison unit having a comparator which compares each of voltages of coil terminals of three phases with a voltage of a neutral point of 3-phase coils to determine which voltage is higher or lower;
- and
- a drive operation unit which calculates, based on a signal outputted from the voltage comparison unit, a zero cross point of a voltage of a position detection phase, of the voltages of the coil terminals of the respective phases by operation, and interrupts a current of the position detection phase by a first time from the zero cross point,
- wherein one interval is defined between the zero cross points at the phases for the coil terminal voltages, and
- wherein the drive operation unit performs the operation using time information measured based on the output signal from the voltage comparison unit at a previous interval and a present interval, and calculates the zero cross point at a next interval using the result of operation.
Dependencies are inferred from the claim text.