Propulsion control apparatus for passenger vehicles

A control apparatus for an electric motor operative with a power source for supplying current to determine the operation of that motor in accordance with a plurality of input requested currents corresponding to respective desired motor operations, the combination of:

• current control means including a plurality of resistors connected in a series circuit between said power source and the electric motor for establishing the actual electric motor current,
• cam controller means coupled with the current control means and movable through successive angular positions for sequentially removing one or more selected resistors from said circuit,
• stepping motor means coupled with the cam controller means for providing a predetermined angular position movement of said cam controller means to determine each sequential removal of at least one of said resistors to control the electric motor current, and
• control means for establishing an initial position of the cam controller means and responsive to each one of said input requested currents for energizing the stepping motor means when the actual electric motor current is less than said one requested current to determine a predetermined angular position movement of the controller means as required to establish the actual electric motor current to provide the desired electric motor operation corresponding to said one requested motor current.