Nidec Corporation

Sgs-thomson Microelectronics S.r.l.

Nippon Densan Corporation

Kohei Yonemura

Isao Kaneda

Carlo C De Martiis

Sandro Cerato

A method of starting a sensorless motor comprising a stator provided with three-phase stator coils to which an exciting current is supplied, and a rotor provided with a rotor magnet for obtaining a rotating torque by the electromagnetic interaction of the stator wherein a first stepping step and a second stepping step for starting the rotor at the time of starting the motor are carried out. In the early period of the second stepping step, a reverse exciting operation is carried out in which an exciting current is switched off from positive to negative or from negative to positive without including a cessation period in two-phase coils out of the three-phase stator coils.

Method of starting a sensorless motor

A DC motor having a housing, a hub member rotatably supported by the housing, a flexible printed circuit board fixedly mounted on the housing, and an IC chip mounted on the flexible printed circuit board and located facing a recess formed in the housing. The hub member has a shaft rotatably supported by a bearing within the recess. The flexible printed circuit board has a metal layer for mounting the IC chip, the metal layer being isolated from a wiring pattern formed on the printed circuit board. The wiring pattern on the flexible printed circuit board is directly connected to a connection pin connected to the motor wiring.

Growing community of inventors

Yokaichi, Japan

Kohei Yonemura