| 摘要 |
PURPOSE:To enable building of PTC thermistors in a case by making the PTC thermistors, which are connected to an armature winding of barium titanate ceramics having such material characteristic as the ratio of the withstand voltage to the resistivity at room temperature is seven or higher. CONSTITUTION:PTC thermistors 12, to both sides of which electromagnets are applied, are sandwiched between plate input terminals 8 and plate brushes 7 and fixed in grooves 10 in resin 9 adhered to the inside of the small case 2 of a motor to make a small motor incorporating PTCs. The PTC thermistors 12 are made of barium titanate ceramics having such material characteristic as the ratio of the withstand voltage to the resistivity at room temperature is seven or higher. Because the PTC thermistors of barium titanate ceramics having the above-mentioned material characteristic have low resistivity at room temperature and high withstand voltage, the size thereof can be remarkably reduced. Therefore, the PTC thermistors can be connected to an armature winding and built in the case of the motor. |
