CWT Ultra-mini | Best Rogowski Current Transducer for Inverters

Measure High-Speed Currents in Tight Spaces with PEM’s CWT Ultra-mini

In today’s high-frequency power electronics systems, such as EV inverters, solar inverters, UPS, and energy storage, engineers face a recurring challenge. How can you measure high-speed AC currents in tight spaces without sacrificing waveform fidelity or safety?

Traditional current sensors like Hall-effect and CTs often fall short:

Limited bandwidth- They cannot capture fast transients.
Bulky size- They are hard to fit around PCB tracks or TO-247 packages.
Magnetic saturation- They show poor accuracy at high currents.
Complex integration- They require extra conditioning circuits.

For labs, R&D, or field testing, especially in inverter design and switching circuits, this is a critical problem.

The Solution: CWT Ultra-mini Rogowski Current Transducer

The CWT Ultra-mini from PEM UK is a next-generation Rogowski current sensor made for tight spaces and high-frequency applications. Now available in India through Pantronics India Pvt. Ltd., the authorized distributor for PEM.

Power Electronic Measurements Ltd (PEM) are established market leaders in the design and manufacture of wideband current measuring devices based on Rogowski technology.

The company provides a variety of standard products to meet different customer needs, along with customized solutions that range from unique, one-off designs to large-scale OEM production.

Technical Highlights

Ultra-Thin Coil: Just ~1.6 mm cross-section; fits around TO-220/TO-247 pins or compact busbars.
Wideband Performance: 30 MHz bandwidth captures fast switching, spikes, and harmonics.
High di/dt Measurement: Handles up to 100 kA/µs; ideal for IGBT/MOSFET waveform analysis.
Built-In Integrator: Outputs ±6 V signal directly; no external integrator required.
Non-Intrusive & Safe: Zero insertion loss and up to 1.2 kV insulation.

The Result: Space-Efficient Current Sensing for Critical Applications

With the CWT Ultra-mini, engineers can now:

Measure high-speed AC and transient currents in EV inverters, BESS, and SMPS.
Perform real-time waveform capture using oscilloscopes or data loggers.
Eliminate bulky current probes and reduce test setup complexity.
Achieve reliable performance without overheating or saturation.

It is the best Rogowski current transducer for inverter testing, lab diagnostics, and field monitoring.

Applications of CWT Ultra-mini

Conclusion

As power electronics systems grow faster, denser, and more demanding, the need for precise, high-bandwidth, and compact current measurement tools is more critical than ever. The CWT Ultra-mini from PEM delivers exactly that, combining the flexibility of a Rogowski coil with top performance in the world’s smallest size.

Whether you’re working on EV inverters, solar systems, BESS, or high-frequency test benches, the CWT Ultra-mini ensures you won’t have to compromise on accuracy, safety, or easy integration.

Now available in India through Pantronics India, the CWT Ultra-mini is the perfect solution for engineers and innovators pushing the boundaries of power systems

Ready to improve your high-speed current sensing with an ultra-thin, clip-around coil that has a typical cross-section of just 1.6 mm?

Contact Pantronics India today for pricing, demo units, or datasheets for the CWT Ultra-mini Rogowski transducer.

CWT Ultra-mini FAQ

FAQs: CWT Ultra-mini Rogowski Current Probe

1. What is the CWT Ultra‑mini?

It is a slim Rogowski current probe (1.6–1.7 mm) for oscilloscopes and DAQs. It offers wide bandwidth up to 30 MHz with minimal circuit interference.

2. What current range and bandwidth does it support?

Current: 30 A to 30 kA peak. Bandwidth: DC to 30 MHz (–3 dB).

3. How does the coil size help?

Its 1.6–1.7 mm coil easily fits tight areas like TO‑220/TO‑247, with negligible effect on nearby circuits.

4. What are the temperature and insulation ratings?

Temperature: –40 °C to +125 °C (coil), 0–40 °C (integrator). Insulation: 1.2 kV peak, tested to 3 kV rms.

5. What about di/dt performance?

Up to 100 kA/μs for high-current models, and at least 70 kA/μs for others.

6. How accurate and linear is the probe?

Accuracy: ±0.2% with central conductor. Linearity: better than 0.05%; ±2% positional error for small conductors.

7. What accessories and power options are included?

Includes: coil, integrator (BNC out), 0.5 m cable, AA batteries or external DC, case, and calibration certificate.

8. Can I get custom versions?

Yes. Custom coil (up to 500 mm), cable (up to 10 m), power adapters, and bespoke designs are available.

9. What are typical applications?

Used in switching waveform testing, power electronics diagnostics, transient/pulsed current testing, EMC validation, and ripple current monitoring.

10. What standards and certifications are met?

Complies with CE, EMC EN61326‑1, IEC 61010‑1 and 61010‑2‑032. Manufactured under ISO 9001:2015 standards.

Pantronics India Pvt. Ltd., with a legacy of 50 years, stands as a trusted leader in delivering comprehensive power electronics solutions..

We offer a wide range of power electronics components and systems from top global manufacturers to empower businesses for growth and success. Our products include power semiconductors, resistors, capacitors, fuses, microcontrollers, circuit protection solutions, thermal management systems, testing and measurement solutions, and high voltage and pulse solution