Rogowski Coils: A Smarter Way to Measure High AC Currents

As power electronics systems continue to scale in current, speed, and complexity, traditional current-measurement methods are increasingly pushed to their limits. From industrial drives and power supplies to energy infrastructure and high-power converters, engineers need a solution that delivers accuracy, safety, and bandwidth, without adding loss or design constraints.

This is where Rogowski coils stand out.

What Is a Rogowski Coil?

A Rogowski coil is a current sensor constructed from a helical winding around a non-magnetic core. Unlike current transformers, it does not rely on a ferromagnetic core. Instead, it operates on Faraday’s Law, producing an output voltage proportional to the rate of change of current (di/dt) flowing through a conductor. Because there is no magnetic core to saturate, Rogowski coils offer excellent linearity across wide current ranges, making them especially well-suited for high-current AC measurements.

Why Engineers Are Choosing Rogowski Coils

No Saturation, No Guesswork

Traditional current transformers can saturate under high current or transient conditions, leading to distorted measurements. Rogowski coils eliminate this risk entirely, providing linear response over current and frequency with no theoretical upper limit on measurable current.

Minimal Power Loss

Rogowski coils are non-intrusive and introduce virtually no insertion loss, preserving system efficiency, an increasingly critical requirement in modern power designs.

Wide Dynamic Range and High Accuracy

With sensitivity reaching up to 720 mV/kA and tight tolerance control, Rogowski coils can accurately measure both low and extremely high currents without sacrificing resolution or stability.

Safer, Non-Contact Measurement

Because the sensor does not need to break the primary conductor, Rogowski coils significantly reduce electrical shock risk during installation and testing, an important advantage in high-power environments.

Easy System Integration

Their compact form factor, flexible mounting options, and compatibility with external integrators make Rogowski coils easy to incorporate into new designs or system upgrades.

Technology Designed for Real-World Applications

Rogowski coils are particularly effective in applications where large AC currents, fast transients, or tight installation constraints are present, including:

• Industrial motor drives and inverters
• Power supplies and SMPS systems
• Energy and power distribution equipment
• High-power converters and test systems

Their combination of wide bandwidth, temperature stability, and low sensitivity to external electromagnetic fields makes them a robust choice for demanding environments.

A Complete Rogowski Coil Portfolio

To support a broad range of design needs, our Rogowski coil offering includes multiple product families:

RC01 – PCB-Mount Rogowski Coils

• Designed for board-level integration, RC01 coils offer high sensitivity, excellent frequency response, and optional shielding, ideal for compact power electronics designs.

RC03 – Non-PCB Rogowski Coils

• With flexible positioning and wired connections, RC03 coils deliver higher sensitivity and easy integration into existing systems where PCB mounting is impractical.

RC05 – Rogowski Coils with Mounting Fixture

• Optimized for fixed installations, RC05 coils combine mechanical stability with reliable high-current measurements for industrial environments.

FLRC – Flexible Rogowski Coils for Extra-High Currents

• For applications requiring maximum flexibility, FLRC coils can be installed under load, support customized lengths and gain options, and handle extremely high current levels with ease.

Rogowski Coils vs. Current Transformers

When compared to current transformers, Rogowski coils deliver several decisive advantages:

• No magnetic saturation
• Superior linearity over current and frequency
• Smaller size and lighter weight
• Competitive cost for high-current applications

For engineers working with modern high-power systems, these benefits translate directly into simpler designs and more reliable measurements.

Part of a Broader Power Portfolio

Rogowski coils complement a comprehensive power and magnetics portfolio that includes current sensors, power inductors, transformers, common-mode chokes, and custom magnetic solutions, enabling complete system-level support from sensing to power conversion.

Quick Facts

• RC Series
• Linear Bandwidth: up to 370 kHz
• Cable length: 250, 1000, 1800mm
• Protection class: IP67 for RC05 & RC07 on request
• Fully customized: individual output signal, coil diameter, cable length and connectors on request.
• FLRC Series
• Bandwidth: up to 210 kHz
• Cable length: 500, 1000, 1500mm
• Protection class: IP67
• Fully customized: individual output signal, coil diameter, cable length and connectors on request.