Patent ID: 11920536
Assignee: nan
Field: Engines, pumps, turbines (Mechanical engineering)
Classification: CPC F | IPC F

Claim 15:
16. A method of operating a fuel pump system for a vehicle, the fuel pump system including a primary fuel pump and an auxiliary fuel pump in-line with the primary fuel pump and fluidly connected to a fuel tank, and an electric motor for driving the auxiliary fuel pump, the method comprising:
providing an electronic control circuit electrically connected to the electric motor, and a pressure sensor at an output of the auxiliary fuel pump;
receiving, at the electronic control circuit, a signal from the pressure sensor corresponding to the output pressure measured by the pressure sensor at the output of the auxiliary fuel pump;
communicating, via a processing device associated with the electronic control circuit, an operational motor speed to the auxiliary fuel pump based on the signal received from the pressure sensor;
continuously adjusting, via the processing device, the operational motor speed based on the signal received from the pressure sensor under normal operating conditions to maintain a predetermined constant output pressure; and
sensing, by the electronic control circuit, a failure or disconnect in the pressure sensor or the processing device, and automatically switching control, via the electronic control circuit, of the operational motor speed from the processing device to a fixed source that is configured to provide a fixed, predetermined operating voltage or power corresponding to a predetermined safe speed in response to sensing the failure or disconnect,
wherein the communicating, via the electronic control circuit, includes communicating a digital signal to a Digital to Analog Converter in the electronic control circuit to maintain the predetermined constant output pressure based on the signal received, at the receiving step, from the pressure sensor; and the continuously adjusting, by the electronic control circuit, under normal operating conditions includes generating, by the Digital to Analog Converter in the electronic control circuit, an analog voltage from the digital signal, and controlling, by an operational motor speed controller in the electronic control circuit, the operational motor speed of the electric motor based on the analog voltage generated by the Digital to Analog Converter,
the method further including providing the electronic control circuit with a switch electrically connected to the operational motor speed controller and switchably connected to the Digital to Analog Converter and the fixed source, and pre-setting the fixed source to the fixed, predetermined operating voltage or power corresponding to the predetermined safe speed, and wherein the automatically switching, via the electronic control circuit, includes automatically switching, via the switch, a source of operating voltage from the Digital to Analog Converter to the fixed source to operate the electric motor at the predetermined safe speed in response to the sensing the failure or disconnect.