| 摘要 |
PURPOSE: To realize fine rotational control by employing a short-circuit brake for a small current and a reverse current brake for a large current in the brake control for a three-phase motor. CONSTITUTION: A comparator 4 compares the voltage for driving a three-phase motor 1 integrated through a resistor 5 and a capacitor 6, and a driver 10 drives the three-phase motor 1 depending on the control signals Uu, Ui, Vu, Vi, Wu, Wi received from a logic section 9. Switching between a short-circuit brake and a reverse current brake is carried out by sampling the PWMin signal at a timing for maximizing the pulse width in PWM modulation. A short-circuit brake is applied when the sample output, i.e., a PWM inverted Short/Rev signal, has Low level otherwise a reverse current brake is applied. |
