Balancing circuit, method of voltage balancing and drive system for a vehicle

An internal combustion engine has an electrical generator/motor coupled to the crankshaft. This either receives power from a battery coupled to a circuit having capacitor (2) storage, or takes power to maintain the charge. The circuit provides a voltage conversion (6) and is based upon transformers (13,15) coupled to control units (18) to provide symmetrical operation. Independent claims are made for: (1) a procedure for the balancing of the tension of several, in row switched energy stores; and (2) a drive system for a motor vehicle.