초록 ▼

In order to prevent the performance of a motor from deteriorating due to a change in which the rotation rate of its rotor is to be increased suddenly, in a brushless motor in which a drive pulse whose pulse width is modulated in correspondence to a rotation rate setting signal input from the outside

In order to prevent the performance of a motor from deteriorating due to a change in which the rotation rate of its rotor is to be increased suddenly, in a brushless motor in which a drive pulse whose pulse width is modulated in correspondence to a rotation rate setting signal input from the outside is formed and switching control is performed on the current supplied to the exciting coils by using output signals from the Hall elements that detect the position of the rotor and the drive pulse, the pulse width of the drive pulse is changed gradually and greatly until it reaches the pulse width that corresponds to the rotation rate setting signal when the upward change in the rotation rate of the rotor is to be large.

대표청구항 ▼

[ What is claimed is:] [1.] A drive control apparatus comprising:a brushless motor including, a rotor having permanent magnets, a stator provided at a position facing opposite said permanent magnets of said rotor, exciting coils wound around said stator operable to generate a rotating magnetic field

[ What is claimed is:] [1.] A drive control apparatus comprising:a brushless motor including, a rotor having permanent magnets, a stator provided at a position facing opposite said permanent magnets of said rotor, exciting coils wound around said stator operable to generate a rotating magnetic field, and a detector operable to detect a position of said rotor;means for switching the direction of a current supplied to said exciting coils;rotation rate setting means for setting a rotation rate for said rotor and for generating a setting signal;pulse-width modulation means for determining a pulse width of a drive pulse based upon the setting signal from said rotation rate setting means;a drive controller operable to perform switching control of said means for switching by using an output signal from said detector and the drive pulse having the pulse width determined by said pulse-width modulation means; andpulse width gradual increase means for gradually and greatly changing the pulse width of the drive pulse until the pulse width is equal to the pulse width determined by said pulse-width modulation means by using a specific time constant when the rotation rate of said rotor increases suddenly.