Hi,
Following are main difference between AC servo motor & DC servo motor
| A.C. Servo Motor | D.C. Servo Motor |
|---|---|
| Low power output of about 0.5 W to 100 W. | Deliver high power output. |
| Efficiency is less about 5 to 20%. | High efficiency. |
| Due to absence of commentator maintenance is less. | Frequent maintenance required due to commentator. |
| Stability problems are less | More problems of stability. |
| No radio frequency noise. | Brushes produce radio frequency noise. |
| Compare to DC servo motor it is relatively stable and smooth operation. | It is Noisy operation. |
| AC amplifier used have no drift. | DC Amplifier used have a drift. |
The Moment of inertia is the measure of an object's resistance to changes in its rotation rate. inertia of the load is a key measure for sizing servomotors.