A variable speed motor includes a main winding including first and second main windings, and an auxiliary winding including first and second auxiliary windings, wherein the main winding and the auxiliary winding are wound on a stator to form a plurality of poles, and a plurality of relays for performing a switching operation between serial/parallel connections of the first and second main windings or the first and second auxiliary windings. The variable speed motor includes a stator on which a 4-pole winding and a 12-pole winding arc wound, a plurality of tap windings connected in series to a 4-pole main winding forming 4 poles, for extending a variable range of rotation speed of the motor during a 4-pole operation mode, and a phase control circuit for varying rotation speed of the motor by controlling a phase of an input power-supply signal during a 12-pole operation mode.