Abstract: A motor controller is provided which improves response to control inversion of a motor, and which also improves controllability and driving comfort when applied to electric power steering. In the motor controller a bridge circuit 5 is formed which includes switching elements 3a to 3d which are driven to control the motor 2 in a direction of conduction, a drive system is switched between a single-phase one-sided chopper system and either a single-phase double-sided chopper system or a double-phase double-sided chopper system based on detected states of an apparatus or the amount of control, so as to control the motor 2 with a drive system suitable for each state of the apparatus.

Abstract: A reversible control apparatus for controlling a motor is provided which is highly durable, weather proof, simple in structure and inexpensive to manufacture. The motor is controllably driven by a motor driver. A target rotational speed determiner determines a target rotational speed for the motor and generates a corresponding output signal. A rotational speed sensor senses the rotational speed of the motor and generates a corresponding output signal having no polarity which indicates the direction of rotation of the motor. A motor controller controls the motor driver. A polarity applying means applies a polarity to the output signal of the rotational speed sensor on the basis of the output signal of the target rotational speed signal and the output signal of the motor controller.