| 摘要 |
In a sewing machine with a universal motor, a speed control for the motor, a lamp, and a plug connection on the sewing machine housing for connecting the power supply and speed control lines to the motor and to the lamp, for equivalent replacement of the normal impedance starter by one with integrated phase angle control, a phase angle control is provided as a speed controller which comprises a rectifier bridge consisting of diodes for current supply to the phase angle control and to the lamp, as well as a rectifier bridge with semiconductor devices controlled by the phase angle control, for the control of the motor. To leave the known three-terminal plug connection on the sewing machine housing for the connection both of the power supply and for the phase angle control, the power supply leads are connected at both rectifier bridges, the negative terminals of which are connected to the common terminal of the motor and lamp, which the positive terminal of the phase angle-controlled rectifier bridge is connected to the second terminal of the motor. The positive terminal of the diode rectifier bridge is connected to the second terminal of the lamp. |
