drehzahlsteuereinrichtung for electric kommutatormotoren household sewing machines

摘要

1289261 Control of A.C. motors NECCHI SpA 19 April 1971 [23 April 1970] 9803/71 Heading H2J Brushes 16 of a commutator electric motor 14 are angularly adjusted to reduce the motor speed and at a predetermined point a rectifying diode 31 is brought into the circuit by a switch to reduce it further. A knob 17 has a cam 21 which moves a rod 22 to deflect the coil spring 23 to which the contact 25 is attached so that at a predetermined point the switch opens or closes the diode by-pass circuit. The knob 17 is also coupled to the brush holder. A rheostat 29 may be used only for starting and stopping and not for speed control.