A river turbine for harnessing a predetermined minimum or baseload value of hydrokinetic energy from river current received at a harnessing module has three modules: the harnessing module, a controlling module and a generating module. Han's principle is that, in a torque balanced speed converter Hummingbird system, the generated electric power (output) from a harnessed input power (input) must exceed the electric power used for the control motor (control). Harnessed power is provided to the power balanced three variable mechanical control system when a control power line graph is crossed by an output power line graph to achieve an electrical advantage. The three variable mechanical motion control system includes a Hummingbird control assembly of first and second spur/helical gear, first and second ring gear and first and second bevel/miter gear Transgear gear assemblies.