This work compares variable speed controllers applied to single phase unbalanced induction motors. The single phase machine feeds from three phase inverters or double H bridges with scalar and vector control. For comparing the machine's performance the controller uses first a classical table based DTC and predictive based DTC for the vector controller, and later a standard V /f for the scalar controller. The simulations use a voltage behind reactance model of the single phase machine implemented in Simulink®, and experimental tests confirm the validity of the simulations. Also, the results show the feasibility of using different controllers, vector or scalar, to obtain low start-up currents, speed regulation and high electric torque, when compared with a direct start-up using capacitors in the auxiliary winding.