Abstract: A rotary encoder has a signal encoding unit fastened at the shaft, a signal detection unit arranged in an axial direction of the shaft disposed opposite to the signal encoding unit, a signal evaluation unit, and an energy generation unit for the generation of electrical energy for the rotary encoder. The energy generation unit has a first element provided at the signal encoding unit and of a second element arranged at the circuit board of the signal evaluation unit. The first and the second element are disposed opposite to one another. The second element has a plurality of coils which are arranged in such a way that two or more coils are displaced by a pole pitch or a multiple of a pole pitch and in that the coils are switched in parallel, in series or in groups.