An electrical writing board includes a bottom color plate, an electrochromic board, a touch panel, and a driving circuit module. Input qualities regarding said targets are received. The pitch drive system is adapted for pitching the at least one rotor blade, wherein the wind turbine further includes a wind turbine control. The magnetic shield also contains a magnetic shielding material that has a magnetic shielding factor of at least about 0. The turnaround devices each have arc guides that adjoin the ends of the two guides and are connected to them and that also transition in the arc from one guide to the other guide.