| 摘要 |
PROBLEM TO BE SOLVED: To obtain a drive device which eliminates a speed change due to a cogging torque in a brushless motor. SOLUTION: Three-phase drive-signal data and correction-signal data which are stored in a ROM 29 are sequentially converted into analog values by D/A converters 30 to 33. Correction-signal data which is output from the D/A converter 33 is multiplied by a correction signal from a correction-signal corrector 49, it is then added to a speed control signal from a speed control circuit 27, their added value is multiplied by drive signals at respective phases, which are output from the D/A converters 30 to 32, and their multiplied results are amplified by amplifiers 40 to 42 at respective phases so as to be applied to coils 22 to 24 at the respective phases. The correction-signal data is used as data which offsets a cogging torque. As a result, drive control signals which are output from the amplifiers 40 to 42 at the respective phases are given to the amplifiers 40 to 42 as signals which offset the cogging torque. |
