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

Claim 1:
2. A fuel pump system for a vehicle, comprising:
a primary fuel pump;
a fuel tank;
an auxiliary fuel pump in-line with the primary fuel pump and fluidly connected to the fuel tank;
an electronic control circuit, the electronic control circuit including a processing device;
a pressure sensor configured to measure an output pressure from the auxiliary fuel pump and to transmit a signal corresponding to the output pressure to the electronic control circuit;
an electric motor configured to drive the auxiliary fuel pump at an operational motor speed, wherein the electric motor is electrically connected to the electronic control circuit; and
wherein the electronic control circuit is configured to continuously adjust the operational motor speed via the processing device, based on the signal from the pressure sensor to maintain a predetermined constant output pressure, and
wherein the electronic control circuit is further configured to sense a failure or disconnect in the pressure sensor or the processing device and to automatically switch control 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, and
wherein the electronic control circuit includes a Digital to Analog Converter in communication with the processing device under normal operating conditions, and an operational motor speed controller electrically connected to the Digital to Analog Converter and to the electric motor, the operational motor speed controller controlling the operational motor speed of the electric motor, wherein the processing device is configured to communicate a digital signal to the Digital to Analog Converter to maintain the predetermined constant output pressure based on the signal from the pressure sensor under normal operating conditions, the Digital to Analog Converter is configured to generate an analog voltage from the digital signal, and the operational motor speed controller is configured to control the operational motor speed of the electric motor based on the analog voltage generated by the Digital to Analog Converter from the digital signal, and
wherein the electronic control circuit further includes a switch electrically connected to the operational motor speed controller and switchably connected to the Digital to Analog Converter and the fixed source, wherein the switch is configured to automatically switch a source of operating voltage to the operational motor speed controller from the Digital to Analog Converter to the fixed source for operation of the electric motor at the predetermined safe speed in response to sensing the failure or disconnect.