The
Gramme dynamo was an
electrical generator patented in 1870 by Belgian engineer
Zénobe Gramme[?] (
April 4,
1826 -
January 20,
1901). The design, using a
ring armature[?], was an improvement on earlier dynamos and helped usher in development of large-scale electrical devices. In 1873 it was discovered that the device could be reversed to serve as a
motor.