Use this electronics calculation for a first-pass component, converter, signal, motor, or sensor estimate when the stated operating conditions and units match the device data.

Winding resistance

Required number input.

Compute the impedance in ohms of a series RLC circuit at resonance, where reactances cancel and only the winding resistance remains. The tool evaluates the supplied inputs together and returns the named outputs below; it does not infer omitted operating conditions or change the units shown.^[1]

Impedance at resonance

The resulting impedance at resonance returned as a number.

• Compact electronics formulas omit some combination of tolerances, temperature drift, bandwidth, loading, parasitics, noise spectrum, nonlinearity, clipping, calibration, layout, and device-specific limits. Typical datasheet values are not guaranteed limits.
• Use finite inputs in the displayed units and preserve more precision than the final presentation requires. Independently verify safety-critical, financial, compliance, or production decisions.

Check the result against the current datasheet and worst-case operating corners, then verify the circuit or measurement with simulation and bench testing where failure matters.

• Common-Mode Choke Impedance

  Estimate one winding's series RL impedance magnitude at frequency f as √[R²+(2πfL)²]. Enter the effective common-mode inductance and resistance at the operating point; real choke impedance also includes core loss, capacitance, and self-resonance.

• Parallel Resonant Impedance

  Compute the dynamic impedance in ohms of a parallel resonant LC circuit at resonance.

• Resonant Circuit Q Factor Calculator

  Compute the quality factor of a series RLC resonator, Q = sqrt(L / C) / R = (omega0 * L) / R; a higher Q means lower damping and a narrower resonance bandwidth.