The new Schaffner FN 9244 series IEC inlet filters, from Westek Electronics , conduct noise insertion loss for both asymmetrical (common mode) and symmetrical (differential) components.
The topology of the filters comprises of two inductors with high saturation levels. It also includes two Y-capacitors for filtering common mode noise and an X-capacitor plus bleed resistor, for differential noise. The marked difference with earlier insertion loss figures is noted for common mode rejection in the band to 30 MHz. The Schaffner FN 9244 series offers an additional 10 dB. The 1 amp version at 150 kHz has an insertion loss of 50 dB (50/50 W input/source impedance).
The Schaffner FN 9244 IEC inlet filters are available in current ranges from 1 amp to 15 amp, have a rated voltage of 250 volts and are usable to 400 Hz. The withstand phase-to-earth impulses of 2.5 kV. The filters are available with an optional earth line choke and in a medical version.