The ferrite ring suppresses high-frequency noise, reducing high-frequency interference in the power cable, signal cable, and connectors. The ferrite ring is usually made of Mn-Zn ferrite. The impedance of the ferrite ring varies with frequency. Normally, its impedance is relatively small to low-frequency signals; however, when the frequency of the signal increases, the impedance increases dramatically, which optimizes signal transmission.

The ferrite ring is commonly used when peripheral devices (such as the controller) are affected by noise from conduction and radiation when the servo motor is in the Servo On state. The parasitic capacitance between the cables in the wiring panel and the ground is typically small, but as the frequency of the signal increases (in the Servo On state), the resistance of the parasitic capacitance becomes small enough for the common-mode current to flow through. Normally, common-mode current only leads to common-mode interference due to an unstable circuit caused by a poor connection in the power circuit or between the servo drive and the ground. If the common-mode current flows through the external cables, common-mode interference may also happen due to electrical interference caused by unstable electric potential.

When suppressing common-mode interference, the ferrite ring causes eddy current losses to high-frequency signals and transforms them into heat. The ferrite ring acts as a low-pass filter to effectively suppress high-frequency noise and ensure the stability of the circuit while the impedance to low-frequency signals is relatively small.

Winding the wires several turns on the ferrite ring can increase inductance and the ability to filter out high-frequency noise. The suggested winding methods are shown in the product images.

Component features:

• Delta part number: ASD-ACFC7K00
• For use with Delta B3 and A3 servo systems (works also with VFDs, and other brands of servo systems)
• Outside diameter: 68 mm (+/- 0.6mm)
• Inside diameter: 44 mm (+/- 0.6mm)
• Height/Width: 13.5 mm (+/- 0.5mm)
• Inductance: 2.6 mH ±25%
• Initial Permeability: 5500