Sewon PM Tech Co,. Ltd. have been specializing in such Powder Metallurgy products as automotive, mechanical and electronic parts etc.
It is needless to say that cost and quality have been always the most important topics in manufacturing industries

This rotor operates at constant speed and has lower starting current

External resistance added to rotor circuit, increases starting torque

Motor running efficiency improves as external resistance is reduced when motor speed up.

Higher torque and speed control

The rotor is a cylindrical core made of steel lamination with slots to hold the wires for its 3-phase windings which are evenly spaced at 120 electrical degrees apart and connected in a 'Y' configuration.The rotor winding terminals are brought out and attached to the three slips rings with brushes, on the shaft of the rotor. Brushes on the slip rings allow for external three-phase resistors to be connected in series to the rotor windings for providing speed control. The external resistances become a part of the rotor circuit to produce a large torque when starting the motor. As the motor speeds up, the resistances can be reduced to zero.