SPEED CONTROL CIRCUIT FOR BRUSHLESS MOTOR

摘要

PURPOSE:To maintain a speed of a motor constant by smoothly controlling the speed of the motor. CONSTITUTION:A speed corrector 6 rotates a brushless motor 3 under no load to obtain a correction coefficient at its pole position so that a detected speed becomes constant and stores it. When it controls a speed of the motor 3 under real load, the corrector 6 multiplies a detected speed by the coefficient at its pole position to correct it. A speed controller 7 so applies a voltage command to a driving circuit 8 that the corrected detected speed becomes equal to a speed set by a switch 9. A driving circuit 8 applies a voltage according to a voltage command to the motor 3 to control the speed of the motor 3.