| 摘要 |
PROBLEM TO BE SOLVED: To provide an inexpensive fan motor control device wherein speed controllability is not impaired even if an energization pattern is set for each carrier cycle when a fan motor comprising a DC brushless motor is driven at an energization angle of 150 deg. by switching energization to the coil of the fan motor every 30 deg.. SOLUTION: Pseudo position signals HL1, HL2 which produce variation in HIGH/LOW level with timing different from timing of position signals HU, HV, Hw from a fan motor 1 are generated, and energization patterns are changed in accordance with variation in input pattern of these position signals and pseudo position signals. As a result the rotational position of a rotor can be judged from the input patterns more finely in a short time, a time to energize the coil can be ensured in one carrier cycle, and favorable speed controllability can be maintained. In addition, since a high-speed microcomputer or the like is not required, the manufacturing cost can be reduced. |
