The electrically variable transmission family of the present invention
provides low-content, low-cost electrically variable transmission
mechanisms including first, second and third (and possibly fourth)
differential gear sets, a battery, two electric machines serving
interchangeably as motors or generators, five, six or seven selectable
torque-transfer devices and possibly a dog clutch. The selectable torque
transmitting devices are engaged to yield an EVT with a continuously
variable range of speeds (including reverse) and up to six mechanically
fixed forward speed ratios. The torque transmitting devices and the first
and second motor/generators are operable to provide five operating modes
in the electrically variable transmission, including battery reverse
mode, EVT reverse mode, reverse and forward launch modes, continuously
variable transmission range mode, and fixed ratio mode.