| 摘要 |
<p>PURPOSE:To improve the reduction of the electric conduction efficiency in the increase of a load, by boosting the electric power source voltage according to the reduction of the car speed, when the electric power source voltage of an on-vehicle battery which is supplied to the motor for steering assistance is controlled on the basis of the control signal applied with the car speed correspondence characteristic. CONSTITUTION:The flip flop FF of an electric power source voltage control circuit 20 receives the output signal of an oscillation circuit OSC and outputs the ac pulse signal. Each pulse width modulation circuit PWN1, PWM2 receives the car speed signal of a car speed sensor 9 as the output signal of each frequency-voltage converter FV, and converts the ON/OFF duty ratio of the ac pulse signal. Accordingly, the car speed correspondence characteristic is applied to the ac pulse signal, and each pulse turning-ON time is increased, accompanied kith the reduction of the car speed. Further, the ac pulse signal is inputted into each transistor T1, T2 of a boosting voltage circuit through each electric power source driving circuit DV1, DV2. A boosting voltage circuit boosts the electric power source voltage of an on-vehicle battery 7 according to the ac pulse signal.</p> |
