NG Electronics · ISO 9001:2015 Certified Company
NG Electronics, an ISO 9001:2015 certified manufacturer in Pune, builds ring-core common mode chokes rated up to 50 A for drives, chargers and inverters, in single-phase and three-phase versions.
A high current common mode choke has an awkward job: it must present a large impedance to noise while the full load current passes through its copper all day. At NG Electronics we wind these parts on ring cores with heavy-gauge wire, covering ratings up to 50 A and inductance from 1 mH to 100 mH. They are intended for the mains or DC input of equipment where a small PCB choke would simply overheat.
In an ideal choke the load current creates no net flux, so the core never approaches saturation. Real windings are not perfectly coupled. A small leakage inductance remains, typically of the order of one per cent of the common-mode value, and its flux does pass through part of the core. At tens of amperes that leakage flux can push a high-permeability core towards saturation, so it has to be checked at peak current, not just at the rated figure.
Copper loss is the other limit. Loss rises with the square of current, so a winding of 1 mΩ carrying 50 A dissipates 2.5 W, and there are at least two such windings on the core. Fewer turns of thicker wire reduce the loss but also reduce inductance, which is why core material matters so much at this power level. The right answer is a balance between impedance, temperature rise and size.
ISO 9001:2015 certifiedThe table shows what we build for power line filtering. Temperature rise and impedance depend on the core and copper chosen, so they are agreed for each design.
| Current rating | Up to 50 A on ring cores; range starts at 250 mA |
|---|---|
| Inductance range | 1 mH to 100 mH |
| Line configuration | Single-phase and three-phase |
| Core materials | Nanocrystalline and high-permeability MnZn ferrite toroids |
| Winding options | Sectional, bifilar and split winding |
| DC resistance and temperature rise | Specified per design |
| Testing | 100% electrical test including inductance, DCR, saturation current and hipot |
| Compliance | RoHS and REACH compliant materials; certificate copies available on request |
Higher current ratings generally mean lower achievable inductance on a given core.
These parts appear wherever a power converter of a few kilowatts or more connects to the mains, to a battery or to a long cable.
Input and output filtering for variable frequency drives and servo amplifiers, where fast switching edges drive common-mode current through motor cables and the panel earth.
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Chokes on the AC input of charger power stages, wound for continuous full-load operation and available in three-phase form for higher power units.
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Grid-side and array-side chokes that limit the common-mode current flowing through panel-to-earth capacitance, which is a frequent cause of failed emission scans.
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Line and load side filtering for online UPS units, where the choke runs at rated current for long periods and low copper loss directly affects efficiency.
Enquire nowStock parts you can order today. View details, add to cart or enquire for a custom variant.
Send the line current, phases, target inductance and available space to sales@ngelectronics.in, or call or WhatsApp +91 83290 52861, Monday to Saturday, 9am to 7pm. A technical quotation follows within 24 working hours.
Nanocrystalline cores offer much higher permeability than MnZn ferrite and a higher saturation flux density, so a given inductance needs fewer turns. That means shorter, thicker copper and less heat, and the lower turn count also keeps winding capacitance down. Permeability stays comparatively stable over temperature. The trade-off is cost, and the tape-wound core must be housed in a protective case. MnZn ferrite remains a sound, economical choice where the current is moderate and space is available.
A three phase common mode choke puts three identical windings on one core, or four where a neutral is carried. In a balanced system the phase currents sum to zero, so their flux cancels just as it does in a two-winding part. Imbalance, and any current returning by another route, does not cancel and adds to core flux. Windings are kept in separate sectors of the ring to maintain clearance between phases and to hold inter-winding capacitance low.
Heavy-gauge toroidal winding is slow, physical work, and variation in how the turns are laid shows up directly in leakage inductance and capacitance. NG Electronics winds every choke in its own Pune facility and measures each one before dispatch. As an ISO 9001:2015 certified company, we keep batch records that link a finished lot to its core and wire supply and to its date of production, which matters when a field issue has to be traced.
As a common mode choke supplier for OEMs, we work to your drawing or develop one with you. Design support is free against firm production intent, a sample is provided without charge for lab approval, and a test certificate accompanies the order on request. Prototype quantities of around 10 pieces are routine, with production lots of custom parts typically between 100 and 1,000 pieces. We ship across India and welcome overseas enquiries.
Call, WhatsApp or use the form with inductance, current and quantity.
Price, lead time and datasheet within 24 working hours.
Sample built in-house for your lab testing and approval.
Production with 100% electrical testing under ISO 9001:2015.
Packed with a test certificate, shipped across India or exported worldwide.
Answers about high current common mode choke from NG Electronics, an ISO 9001:2015 certified company
Mainly heat and leakage flux. Copper loss grows with the square of the current, so winding resistance sets the temperature rise. Separately, the small uncancelled leakage flux grows with load current and can saturate a high-permeability core, which collapses the impedance. A sound design checks both at the highest continuous and peak currents the equipment will see.
Not always. Nanocrystalline material gives more inductance per turn and tolerates more flux, which helps most when current is high and space is tight. MnZn ferrite costs less and performs well in many filters, particularly at moderate current. The choice depends on the frequencies you need to attenuate, the size available and the budget, so we often quote both for comparison.
Yes, and many filters rely on it. The leakage inductance of a sectionally wound toroid acts with the X capacitors as a differential-mode stage, which can remove the need for a separate line choke. The limit is saturation: the leakage flux passes through the core, so the more leakage you design in, the lower the current at which the core begins to saturate.
Yes. Our ring-core range includes three-phase power line filtering parts with three windings on one core, rated up to 50 A. Tell us whether a neutral conductor passes through the filter, the line voltage, and the expected current imbalance, because unbalanced current does not cancel in the core and has to be allowed for in the design.
Every unit is electrically tested rather than sampled. The checks cover inductance, DC resistance, Q factor, saturation current and a hipot test of the insulation. Measurements are made with LCR testers, impulse testers and insulation breakdown testers in our Pune facility. A test certificate can be supplied with the order on request.
Once the specification is agreed, custom samples typically take 7 to 10 working days. The technical quotation itself is sent within 24 working hours of receiving your requirements. A free sample is supplied for approval in your lab before production starts, and single-piece prototypes are possible where the design is new.
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Learn moreSend your specification or drawing for high current common mode choke. NG Electronics is an ISO 9001:2015 certified company, and every enquiry is answered by our engineering and sales team in Pune.
ISO 9001:2015 Certified
Manufacturer of Toroidal Inductors,
Ferrite Transformers & Magnetic Components.
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