Control system for an electric automotive vehicle

Claim 1

A control system for an electric vehicle comprising, a D.C. motor having an armature and a field winding, a first battery, a second battery, a third battery and a fourth battery, a normally open switch means adapted to be closed in normal operation of said motor for connecting said batteries in parallel to a series circuit through said armature and said field winding to apply a first voltage thereto, a first switching means, for connecting said first and second batteries in series, a second switching means for connecting the pair of said first and second batteries, connected in parallel, in series to the pair of said third and fourth batteries, connected in parallel, to apply a second voltage to said armature and said field winding, a third switching means for connecting said third and fourth batteries in series, said three switching means in their closed positions connecting said batteries in series to apply a third voltage to said armature and said field winding, each two of said batteries adjoining to each other being connected in parallel through two uni-directional devices with said switching means opened, each said uni-directional device being connected, through one of said switching means in its closed position, in series to one of said batteries respectively with the opposite polarity thereof to prevent the short circuiting of said batteries, said normally open switch means being connected to one polarity of said batteries and being opened in decelerating operation of the motor, a switching device having a first contact point, a second contact point and a movable contactor, said movable contactor being connected to the first contact point in normal operation of the motor and to the second contact point in decelerating operation of the vehicle, said armature being connected to said batteries at one end through said normally open first switch in its closed position and connected to said first contact point at the other end, said field winding connected to the movable contactor at one end and to the other polarity of said batteries at the other end, a first resistor connected in series with said field winding between the movable contactor and the other polarity of said batteries, second resistor connected between said second contact point and the one end of said armature, a uni-directional device for connecting the movable contactor to one polarity of said batteries with such a polarity that current flows from said movable contactor to the one polarity of said batteries, and means for interrupting current to flow from said armature to the other polarity of said batteries in normal operation of the vehicle And permitting the current to flow from the other polarity of said batteries to the other end of said armature in decelerating operation of the vehicle, said means connecting the other polarity of said first battery with the other end of said armature, wherein said batteries are charged in parallel during decelerating operation of said vehicle.