The invention provides a convenient method for controlling direction of rotation of a
synchronous motor of a single-phase permanent
magnet. The method comprises the following steps: A. arranging a power switch of
stator exciting current and ensuring the power switch to conform to the following requirements: when a rotor of the permanent
magnet is motionless, the power switch is conducted after the power
voltage is connected, or after the rotor of the permanent
magnet rotates, the power switch is conducted if the direction of rotation conforms to the set requirement, or after the rotor of the permanent magnet rotates, the power switch is turned off if the direction of rotation is opposite to the set requirement, and when the rotor of the permanent magnet only shakes or wriggles, the power switch is conducted; B. arranging a
permanent magnet rotor field polarity sensing device obtaining the real-time field polarity of the
permanent magnet rotor in designated position; and C. using the simplest sequential
logical circuit to complete each judgment in the step A, thus implementing control of the direction of rotation of the rotor of the permanent magnet. The invention has the advantages of simple and practical control method, simple
control circuit, low cost, high reliability, strong
interference resistance, capability of effectively reducing the noises of
thyristor switches, etc.