The paper deals with autimatic balancing of rotating systems during operation. After discussion of existing techniques the novel concepts of balancing mechanisms are presented. The proposed method are easy to apply to various rotating devices, with no need of machine construction modification. Next basics of active balancing control algorithms are presented, and designed detection and correction algorithms are discussed. After descriptions of mechanisms, measurement and control algorithms, simulation and experimental results are presented. The paper ands some conclusions about presented active balancing mechanisms and further works directions are presented.