A programmed switching system for converting direct current into alternating current or some
other variable current, or for converting alternating current of one frequency into alternating
current of another frequency. The system employs a number of stages connected in
cascade. Each stage includes an electrical energy source or an electrical energy storage
unit and switch means adapted to bypass the energy source or storage unit, to interconnect
the source or storage unit with other electrical energy source or storage units across a load …