A drive control device of an unconnected motor capable of resolving power shortage and increasing motor output without using a boost circuit, and an
electric power steering device using the unconnected motor. The drive control device comprises an unconnected motor (12) having a rotor in which permanent magnets are allocated and a
stator opposing the rotor, in which armature winding Lu to Lw of a plurality (N number) of phases are independently arranged, a pair of
inverter circuits (34a, 34b) individually connected to both ends of each armature winding, and a drive
control circuit (15) which drives the pair of
inverter circuits (34a, 34b) with a predetermined number (e.g. 2N) of PWM drive control signals.