Met electronic tension device using e hysteresis control principle of damping, and the non contact type brake, thus the whole device issued a portion of the heart in addition to the mechanical friction of bearing, there is no any mechanical friction, so that the whole set of equipment stability, durability, high speed operation of catering to have been greatly improved. Tension control core body are installed in the interior of the tension device, the tension is lightweight, only from the external supply DC24V power supply, regulating access to the required tension, also equipped with anti jumper institutions, as well as the tension decay control circuit and wire break detection system.