An activation circuit and a method for operating an activation circuit for a DC motor having an electrically actuated stopping brake, in particular for adjusting a rotor blade of a wind or water power facility. The activation circuit includes an emergency operation supply unit and a three-phase bridge inverter. The emergency operation supply unit is connected so it is disconnectable via an emergency operation network switching element to the intermediate circuit of the three-phase bridge inverter, the DC motor is connected via an emergency operation motor changeover element either to the three-phase bridge inverter or to the emergency operation supply unit, and the stopping brake is connected via an emergency operation brake changeover element either to the three-phase bridge inverter or to the emergency operation supply unit.