Electromagnetic clutch slip, in the case of operation of the transmission part, by changing the purpose of the clutch operating voltage to adjust the torque, allowing the pass in the friction plate slipping torque, apply to the tension control system. It works, the coil is energized to produce magnetic, magnetic field lines from the yoke by the baffle, the armature to form a closed loop. Armature and baffle pull, friction plate and adjust the mother pressed to pass the moment. The required torque by adjusting the voltage. When the coil power, torque transmission is terminated.