摘要 |
A fuel supply system comprises an engine control unit (ECU), a fuel pump with a built-in pump motor which is PWM controlled based on a control signal from the ECU, a pump controller for controlling supply of electric power to the pump motor, and sensors for detecting an operating state of the engine. A control section of the pump controller controls to change a frequency to be lower as a duty ratio of a PWM control signal to operate a power transistor of an output circuit is higher and inversely to change the frequency to be higher as the duty ratio is lower.
|