To reduce the cost of an air conditioner by using a geared-down motor having a smaller output than a conventionally used one, and supply required torque without retarding an execution speed of a driving command.
While a flap is driven, the driving frequency of a step motor is reduced as a function of required torque supplied by the step motor to move the flap. For the flap movement, information representing the required torque supplied by the step motor to move the flap is continuously collected. If an increase is detected in the required torque, the driving frequency is reduced, and if a reduction is detected in the required torque when the driving frequency is lower than a given maximum driving frequency, the driving frequency is increased. Electric power for an actuator can be thus limited while coping with a momentary peak value of the required torque.
RICHARDOT PHILIPPE
Next Patent: METHOD AND ARRANGEMENT FOR CONTROLLING MIXTURE AIR IN AUTOMOBILE HEATER OR AIR CONDITIONER