| 摘要 |
The present invention is used to drive a vibrating-feeder main body (1) provided with a base (11), a movable body (12) elastically supported by the base (11), an electromagnet (14) provided to the base (11), and a magnetic core (15) provided to the movable body (12) so as to face the electromagnet (14), the present invention being configured so as to be provided with a PWM signal generating unit (33) for generating a PWM signal on the basis of a set drive frequency (f) and applying to the electromagnet (14) a pseudo alternating-current voltage corresponding to the PWM signal, an electric-current detecting unit (34) for detecting the electric current flowing to the electromagnet (14) by the pseudo alternating-current voltage, electric-current variation rate generating units (35, 36) for generating electric-current variation rates (Rθ1, Rθ2) at reference phase angles (θ1, θ2) set in advance in one cycle of the pseudo alternating-current voltage on the basis of a detection value from the electric-current detecting unit (34), and a frequency correcting unit (37) for correcting the drive frequency (f) on the basis of the electric-current variation rates (Rθ1, Rθ2) for the reference phase angles (θ1, θ2) obtained through use of the electric-current variation rate generating units (35, 36). |
