| 摘要 |
<p>A main power supply (7) and an auxiliary power supply (17) for supplying power to a motor (4) are provided. A MOS-FET (11) for supplying power from the main power supply (7) and a MOS-FET (12) for supplying power from the main and auxiliary power supplies (7,17) are provided. When a phenomenon in which a rotor (4r) of a motor (4) is rotated by the going-back force of steered wheels occurs, and voltage V G of power generated by the motor (4) satisfies the relation V G > V B + V C where V B is a voltage of the main power supply (7) and V C is a voltage of the auxiliary power supply (17), a control circuit (23) and a gate drive circuit (14) turn off both MOS-FETs (11,12) so as to charge the auxiliary power supply (17) using the voltage V G through a parasitic diode (12d) of the MOS-FET (12).</p> |
