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.
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:
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.
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.
Pre-tests showed a 15dB improvement at worst-case frequencies.
Final lab test: Passed EN 55011 Class B with 6dB margin!
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.
P.S. Ask about our “EMC FastPass” service – 83% of fixes completed in under 5 days.
2F building D Mao yuan industry area, Huan guan south road, Guan hu street, Long hua district, Shenzhen city.
Contact person: Vicky Lee
Tel: +86 19925448748
WhatsApp:86-18003057179