Merits
- Low speed and high torque - direct drive
- Quick response, wide velocity range, hard brake and no backlash: excellent controllability; fine position resolution.
- High power/weight ratio and high efficiency.
- Quiet drive.
- Compact size and light weight.
- Simple structure and easy production process.
- Negligible effect from external magnetic or radioactive fields, and also no generation of these fields.
Demerits
- Necessity for a high frequency power supply.
- Less durability due to frictional drive.
