High Current Filtering Technology – The HPR Series

NexTek’s HPR series of extremely high current filters is ruggedly designed to operate at current levels up to 400 amperes and voltages up to 500 Vdc. A large range of available capacitance provides significant insertion loss at frequencies as low as 1 KHz, and provides over 60 db insertion loss to above 1 GHz. The unique ability to remove high frequency noise from very high current lines makes our patented HPR a proven and economical solution to your high current filter application.

EMI filters use two basic elements: series impedances, usually inductors, and shunt impedances, usually capacitors. These capacitors and inductors, configured as a low pass filter, reduce unwanted electrical energy entering or leaving a circuit. The capacitor’s impedance is severely affected by lead inductance. Leaded capacitors are ineffective filters above the self resonant frequency, usually greater than a few megahertz, due to parasitic lead inductance. To achieve high frequency filtering, lead length must be very near zero.


The preeminent filtering challenge is to maintain the required capacitive shunting performance at high frequencies. It is difficult to attach capacitors to high current lines while maintaining the required minimum lead length.

The HPR high current filter capacitor from NexTek provides a unique solution to designers faced with these high frequency filtering needs on high current lines, especially noise from 1 MHz to over 1 GHz, for currents up to 250 Amperes. Unwanted RF noise is filtered to improve power and/or signal quality.

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