摘要 |
A fuel delivery system for an internal combustion engine that includes a fuel supply, an electric-motor pump for feeding fuel under pressure from the supply to an engine, and electronic control circuitry for applying electrical power to the pump. The control circuitry includes a pressure sensitive switch coupled to the pump and responsive to pump outlet pressure for switching between conductive and non-conductive switch conditions at a preselected pump outlet pressure. A pulse width modulation amplifier is coupled to the switch for applying pulsed d.c. energy to the pump at a first average voltage level when the pressure switch is in one condition, and at a second lesser but non-zero level when the pressure switch is in the other condition. In this way, electrical power is applied to the pump motor at a reduced level when pump outlet pressure exceeds the threshold level of the pressure switch.
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