| 摘要 |
PROBLEM TO BE SOLVED: To provide a motor drive unit wherewith overcurrent state of a drive circuit is detected without use of a direct current sensor and an electric power assisted power steering device using the drive unit. SOLUTION: An electronic control unit 10 comprises a drive circuit 12 connected between a direct-current power supply 16 and a ground 17; and a smoothing circuit 20 for smoothing the generated voltage of the direct-current power supply 16. The smoothing circuit 20 is connected in series with a capacitor 22 and a current sensor 21 for detecting the charging/discharging current of the capacitor 22. The current sensor 21 is constituted of an alternating current sensor including an annular magnetic material 211 installed so that a conductor through which the charging/discharging current of the capacitor 22 is passed is encircled therewith; and a coil 212 wound around the annular magnetic material 211. If the value of a detection signal of the current sensor 21 is not less than a predetermined threshold, it is judged that overcurrent is supplied from the direct-current power supply 16 to the drive circuit 12. Then, power supply from the direct-current power supply 16 to the drive circuit 12 is stopped. |
