Читать книгу Analysis and Control of Electric Drives - Ned Mohan - Страница 34

Most electric motors are of a rotating type. Consider a lever, pivoted and free to move as shown in Fig. 2-4a. When an external force f is applied in a perpendicular direction at a radius r from the pivot, then the torque acting on the lever is

(2-10)

which acts in a counterclockwise direction, considered here to be positive.