Domestic manufacturers have developed a new type of digital foil winding machine, the machine uses DC motor foil tension, which is characterized by tension adjustment convenience, accuracy, good stability, winding the whole process of tension remains unchanged, which can ensure that the coil Winding quality. In particular, its tension adjustment range, more suitable for thin foil winding, foil edge will not cause damage. And the tension motor in the tension state is in power generation, the generated energy can be fed back to the winding motor or power grid, friction friction energy consumption without friction braking tension, energy-saving significantly. Moreover, the control system will automatically calculate the coil diameter of the uncoiler so as to adjust the output torque of the motor at any time to ensure a constant tension throughout the winding process, which plays a key role in ensuring coil quality. At the same time, the device adjusts the system by photoelectric analog sensor non-contact detection foil edge, through servo motor dynamic correction, the system of high precision, fast response, high reliability, high precision. According to available information, the equipment technology has been in the world's leading level.