Patent ID: 7560881

Claim:
An electric fuel control system for supplying a total drive torque to a fuel metering pump, the system comprising: a first main drive motor operable, upon being supplied with current, to generate a torque proportional to the current supplied thereto; a second main drive motor coupled to the first main drive motor and operable, upon being supplied with current, to generate a torque proportional to the current supplied thereto; a backup drive motor coupled to the first and second main drive motors and operable, upon being supplied with current, to generate a torque proportional to the current supplied thereto; a main motor control coupled to the first and second main drive motors, the main motor control operable to selectively designate either the first main drive motor or the second main drive motor as an active main drive motor, the main motor control further adapted to receive a first command signal representative of the total drive torque and further operable, upon receipt of the command signal, to control the current supplied to the active main drive motor such that the torque generated by the active main drive motor is a fraction of the total drive torque; a backup motor control coupled to the backup drive motor and adapted to receive a second command signal, the backup motor control operable to determine operability of the main motor control and responsive to the second command signal to control the current supplied to the backup drive motor such that: (i) if the main motor control is operable, the backup drive motor and the active main drive motor together generate the total drive torque, and (ii) if the main motor control is inoperable, the backup drive motor generates the total torque.