Schaffner’s common mode choke: superior performance, same size

Based on nanocrystalline core technology, the addition to Schaffner’s popular RT series will include the RT8121, RT8131, RT8521, and RT8531. The new RT series N achieves up to 15dB higher attenuation performance than its ferrite-based predecessor across relevant frequency bands of the electromagnetic compatibility (EMC) frequency spectrum.

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 choke is the same 65mm in diameter as Schaffner’s existing series but will provide designers with more power while having to work within tight space restrictions and reduces the need to use an external EMC filter.

With rated currents from 25A to 63A at 60°C and operational voltages up to 600VAC and 450VDC, the new choke is particularly suited for use at frequencies from 10MHz to 30MHz. Ensuring cost-effective PCB designs for up to 100A with forced cooling, the choke is available in horizontal and vertical PCB mounting options to suit specific design requirements. Other features include a broad range of inductance ratings (3mH to 13mH), low magnetic leakage flux and superior winding insulation.

Offering a choice of two-wire and three-wire configurations for DC, two-line AC, and three-phase applications, the new common mode choke will be of particular interest to machine and electronics manufacturers that have power demand for their applications from 10kW to 80kW. 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 customisations 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. While not all applications will require the extra power provided by the new RT series N, designers will be able to use the choke as a safety option to improve EMC levels should a measurement fail.

Felix Wedel, Strategic Product Manager at Schaffner, says: “As a global leader in power quality, we are excited to be offering our customers this new core technology option for the RT choke series. With new regulations in preparation for EMC compliance measured at 9kHz, our new offering provides designers with a fallback solution with higher performance and same dimensions.”

“The new chokes not only deliver excellent impedance throughout relevant parts of the EMC frequency band while retaining a compact footprint, but they also simplify the design process. They achieve this by offering different mounting options combined with much greater performance levels than have ever been possible before.”