Generator drive

The drive (1) has a drive element (3), e.g. the crankshaft (4) of an IC engine (5), coupled to the electrical generator (2) via a continuously variable rev conversion unit (6), e.g. a viscosity clutch (11) with a variable slip between the driving and driven clutch elements (9,10), for providing a constant output revs. The regulation of the rev conversion unit can be provided mechanically, electrically and/or hydraulically.