| 摘要 |
PROBLEM TO BE SOLVED: To flexibly set the rotational speed of a cooling fan motor, depending on a temperature.SOLUTION: A first computing unit 142 subtracts third digital data MIN_DUTY indicating the minimum value of a duty ratio from first digital data Sindicating a duty ratio for PWM driving. An inclination calculator 141 generates inclination data α depending on the temperature on the basis of second digital data temp indicating the temperature. A second computing unit 143 multiplies the inclination data α by the output data of the first computing unit 142. A third computing unit 144 adds the output data of the second computing unit 143 to the third digital data MIN_DUTY. Upon receiving the output data of the third computing unit 144 and the third digital data MIN_DUTY, a selector 146 selects either one corresponding to a code of output data of the first computing unit 142, and outputs the selected one as a duty ratio control signal S. |
