AC servo has the characteristics of constant torque under rated speed. Common 200W, 400W low and medium inertia AC servo rated speed is 3000rpm, the maximum speed is 5000rpm, and the speed is high. The torque is proportional to the current, and it can work in torque mode, such as locking screws, crimping terminals and other occasions that require constant torque. The AC servo has very little noise and vibration and low heat generation. The motor inertia rotor inertia is small under the same volume, and the 400W servo inertia is only equivalent to the rotor inertia of the 57 base 2NM stepper motor. The servo has a short-time overload capability, and the motor overload multiple during acceleration and deceleration should be considered when selecting a model.