New Common Mode Choke for Industrial Applications Provides Superior Performance within Same Compact Footprint

Jun 17, 2024
Felix Wedel

Schaffner’s new RT series N choke delivers higher attenuation levels than previous versions but while retaining the same mechanical volume. 

Nanocrystalline Core Technology

Based on nanocrystalline core technology, the new RT series N includes the RT8121, RT8131, RT8521 and RT8531. This extension to Schaffner’s popular RT series achieves up to 15 dB higher attenuation performance than its ferrite-based predecessor across relevant frequency bands of the electromagnetic compatibility (EMC) frequency spectrum. The choke is still 65 mm in diameter but will provide designers having to work within tight space restrictions with more power while avoiding the need to use an external EMC filter.

Eliminating EMI

By filtering electromagnetic common mode noise on the grid side of an electrical device, the RT series N eliminates the problem of electromagnetic interference (EMI) directly on a PCB. The new common mode choke will be of particular interest to machine and electronics manufacturers that have power demand for their applications from 10 kW to 80 kW.

Ideal for use in power supplies that are used in EV charging stations and robotics, the high-quality choke features an approved UL insulation system which enables customizations to be achieved with ease. Other typical applications include photovoltaic inverters, converters, uninterruptible power supplies (UPSs) and switch mode power supplies, LED lighting, communication devices and medical/laboratory equipment.

Simplifying the Design Process

The new choke not only delivers excellent impedance throughout relevant parts of the EMC frequency band while retaining a compact footprint but it also helps to simplify the design process. This is because there are horizontal and vertical PCB mounting options as well as the choke offering a choice of 2-wire and 3-wire configurations for DC, 2-line AC and 3-phase applications.

Key Features 

  • Rated currents from 25 A to 63 A at 60°C
  • Operational voltages up to 600 VAC and 450 VDC
  • Especially suited for frequencies from 10 MHz to 30 MHz
  • Broad range of inductance ratings (3 mH to 13 mH)
  • Low magnetic leakage flux
  • Superior winding insulation