| 摘要 |
The electric motor has two windings (1, 2) from which in each case one connection is connected to one of two power supply connecting terminals (7, 8). There is furthermore a power changeover switch (3) which has two operating positions, the motor emitting full power in the first operating position and reduced power in the second operating position. In the first operating position, the full power supply voltage is supplied to the first winding (1) and a series circuit, formed from the second winding (2) and a capacitor (4), is connected in parallel with the first winding. When the power changeover switch is in the second operating position the series circuit formed from the two windings (1, 2) is connected to the power supply voltage, and the said capacitor (4) is connected in parallel with the first winding (1). In order to increase the starting torque of the motor when the power changeover switch is in the second operating position, there is a series circuit which is formed from a further capacitor (5) and a PTC thermistor (6). When the power changeover switch is in the first operating position, the last-mentioned series circuit is ineffective and, in the second operating position, this series circuit is connected in parallel with the first-mentioned capacitor and the first winding. During the starting phase of the motor, both capacitors are effective and, after starting, the resistance of the PTC thermistor increases so greatly that the further capacitor becomes ineffective. <IMAGE>
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