The radio buttons in the top right corner allow you to choose a AC generator (without commutator), or a DC generator (with commutator). You can change the direction of rotation by using the corresponding button. The sliding control lets you vary the rotational speed. You can stop and continue the simulation with the button "Pause / Resume". This, however, does not mean a real stop of the movement, for in this case the induced voltage would be reduced to zero. Foreign language versions available.