| 摘要 |
PROBLEM TO BE SOLVED: To improve control performance of a control unit as well as to damp electromagnetic sound to be generated on a DC motor. SOLUTION: In a speed controller, a filter 1 constituted of a condenser, a resistor and a reactor is connected parallel to a D.C. motor 5, and a resonance circuit is constituted of a D.C. reactor 4, the D.C. motor 5 and the filter 1. Electric power converters 2, 3 for converting A.C. power into D.C. power by using a plurality of transistors 21 to 26 and 31 to 36 as switching elements are provided, and only armature current of the D.C. motor 5 is fed back to a current feedback circuit. |
