Cases

The EMC Challenge: How We Saved a Failing Single-Phase Power Filter When an industrial automation company approached us in a panic, their situation was dire. Their single-phase power filter—a critical component for protecting sensitive medical imaging equipment—had failed EMC testing three times at a certified lab. With their product launch deadline looming and penalties mounting, they needed a miracle. The Problem: A Filter That Couldn’t Filter The client’s filter was designed to clean up noise from variable frequency drives (VFDs) but failed spectacularly during: Conducted Emissions (CE) tests (EN 55011) – Noise spikes at 150kHz–30MHz exceeded limits by 12dB. Radiated Immunity (IEC 61000-4-3) – The filter’s own shielding was resonating at 50MHz, worsening interference. Their engineering team had tried everything: extra capacitors, toroidal chokes, even a full PCB redesign. Nothing worked. Our Breakthrough We took possession of the filter and assembled a SWAT team of EMC specialists. Here’s how we turned it around in 7 intense days: Day 1–2: Forensic Analysis Discovered the Y-capacitors were creating a ground loop via the chassis. Oscilloscope traces revealed ringing at 2MHz from poor damping in the LC stages. Day 3–4: Surgical Modifications Replaced generic X2 capacitors with low-ESR film types (reduced HF losses by 40%). Added a common-mode choke with nanocrystalline core (suppressed 30MHz+ noise). Redesigned the PCB layout to minimize parasitic coupling. Day 5–7: Validation & Victory Pre-tests showed a 15dB improvement at worst-case frequencies. Final lab test: Passed EN 55011 Class B with 6dB margin! Why This Matters for You Many filters fail not because of poor design, but due to hidden interactions between components. Our approach combines: Deep EMC expertise (we’ve fixed 200+ filter designs). Advanced tools like near-field probes and 3D EM simulation. Real-world solutions – no theoretical "textbook fixes." Need Your Filter to Pass EMC?Just provide:✅ Target standards (e.g., MIL-STD-461, CISPR 32).✅ One sample unit (or even just schematics). We’ll deliver:✔ Diagnostic report within 48 hours.✔ Modified design that actually passes.✔ Test-ready unit – no guesswork. Contact us today. Let’s turn your EMC nightmare into a compliance success story.