Method for adjusting a braking torque and permanently excited magnetic hysteresis brake

The invention provides a method for regulating brake torque and a permanent excitation hysteresis brake (1) which includes: support roller (7) rotatable about a fixed axis (9); magnetic component (3) and hysteresis component (2), as well as regulating device, wherein positions of the magnetic component (3) and the hysteresis component (2) can be mutually regulated by the regulating device and thereby torque acting on yarn through support roller can be regulated. The hysteresis brake (1) has only one mechanical actuator (18) for regulating brake torque. Two regulations are implemented by beingactuated by the one actuator (18): the brake torque is regulated to a necessary value for operation of the hysteresis brake (1) and is regulated as calibrating the hysteresis brake (1). Thus, structure and operation of the hysteresis brake (1) can be simplified. The hysteresis brake (1) is applicable for keep uniform thread tension on textile machine.