FAQ
Technical FAQs for Power Magnetics
This FAQ hub answers the most common technical questions from power engineers, buyers, and sourcing teams—covering topics such as inductance behavior, saturation current, core materials, EMI, reliability, and production processes.
All answers are written to support application-based design decisions and guide users toward the most suitable Coilmaster solutions.
Motor drives and inverters generate strong common-mode and differential-mode noise due to fast switching and large voltage transitions. Magnetic flux leakage from inductors and chokes can couple into nearby...
Read moreMolded inductors reduce magnetic leakage and provide soft saturation, while flat-wire structures lower copper loss and improve current handling. Together, these structures help achieve higher efficiency,...
Read moreSolar and energy storage systems operate over wide temperature and load ranges. Inductors with unstable core materials or high losses can drift or overheat, affecting voltage regulation, efficiency, and long-term...
Read moreShielding contains magnetic flux inside the inductor, reducing radiated and conducted noise. This makes it easier to pass EMC tests and prevents interference with sensitive control, measurement, and communication...
Read moreWhen power stages operate near thermal, current, or EMI limits—as in inverters, motor drives, and ESS—system-level evaluation is more reliable than datasheet-only comparison. Real operating conditions...
Read moreCommon coupling paths include parasitic capacitance from switch nodes to chassis or ground, cable shielding and motor winding capacitance, and leakage fields coupling into sensor and communication harnesses....
Read moreHigher dv/dt increases common-mode current and raises EMI risk, while higher switching frequency shifts the noise spectrum and increases sensitivity to core loss. Magnetics must therefore be evaluated...
Read moreFlat-wire structures are typically preferred when copper loss dominates and thermal margin is tight. Their low DC resistance reduces I²R loss and helps maintain efficiency and reliability under continuous...
Read moreDifferential-mode filtering targets noise between the power lines, while common-mode filtering targets noise that returns through chassis or ground. Inverter systems often require strong common-mode suppression...
Read moreDatasheet current ratings may not reflect inverter ripple and real thermal conditions. Designers should consider RMS current, peak transient current, allowable temperature rise, and inductance drop under...
Read moreLeakage magnetic fields can induce noise into nearby sensitive wiring, causing measurement jitter, communication errors, or control instability. Shielded or molded structures and careful placement help...
Read moreKey inputs include DC-link voltage range, switching frequency, phase current (RMS and peak), target inductance or impedance band, operating ambient temperature, available footprint or height, and the EMC standard...
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