Drive control circuit for three-phase brushless motor, motor-driven blower and electric vacuum cleaner

摘要

The present invention aims to first start the rotation of a rotor according to a first sequence for causing currents to flow in armature windings of three phases U, V and W upon startup of a three-phase brushless motor to thereby reduce an inrush current at the startup thereof, thus making it possible to lighten an electrical load on each electronic part used for control. Also the present invention aims to perform switching to an original second sequence for causing currents to flow in the armature windings of the two phases U and V, V and W or W and U of the three-phase brushless motor after the startup of the three-phase brushless motor to thereby provide a period for an open state of each terminal and make dead band control or the like unnecessary, thus making control of the three-phase brushless motor easier.