An electrically variable transmission includes a power source, three
differential gear sets, first and second motor/generators each connected
to at least one of the gear sets, and torque-transmitting mechanisms. An
input member transfers power from the power source through the
differential gear sets to an output member. The torque-transmitting
mechanisms are selectively engageable to provide an input-split first
electrically variable mode having equal forward and reverse speed ratios
for given input speeds and to provide substantially equal fixed forward
and reverse speed ratios.