Nippon Densan Corporation

Yosuke Kawate

Shuji Takahashi

Fumihiro Morikawa

Tadashi Kato

Mineyo Endo

Eiji Yanai

Norihiko Nakano

A fan motor has a pair of ball bearings placed in the vicinity of each end of an inner side of a bearing race. A plurality of projections are sequentially placed circumferentially around a center portion of the bearing race to axially locate both the ball bearings. A plurality of low-profile projections are sequentially formed between neighboring projections on the inner side surface of the bearing race and are axially elongated from one installing position to that of another installing position of respective ball bearings. The ball bearings are supported by the inner side of each low-profile projection respectively at one end portion and the other end portion of the low profile-projections.

Fan motor

Starting, accelerating and rated rotation of a rotor is carried out without any detector for the rotor position. A motor is controlled with an openloop circuit a short time in a starting area of low speed rotation, and thus the motor can be certainly started. In a rated rotation area, turning timing of the motor is precisely controlled by detecting counter-electromotive force of a stator coil.

Starting and control method for brushless DC motor

A battery charger and a charge controller therefor are disclosed, the battery charger including a supply circuit for supplying a charging current to a battery and a control circuit for controlling the supply of the charging current to the battery. The control circuit shuts the charging current when the detected voltage of the battery is smaller than the maximum peak value by a predetermined quantity. A control means shuts the charging current after a predetermined time has elapsed from a time at which the detected voltage of the battery has raised to the maximum peak value. The control means reduces the charging current when the detected voltage of the battery is made to be a switching voltage. Furthermore, the control means shuts the charging current after a predetermined time has elapsed after the charging current had been reduced.

Growing community of inventors

Hikone, Japan

Yosuke Kawate