Magnetics & Transformers
Every magnetics & transformers calculator on CalcEngines — unit converters, derived indices and interpretive tools, each with its formula, a worked example and the reference intervals it is judged against.
11 calculators in this section
- B-H Curve and Core Loss CalculatorThe hysteresis loop a core actually traverses at your drive level, drawn from an arctangent loop model fitted to your material's quoted numbers — with the area it encloses as the hysteresis loss per cycle, the peak flux density against saturation, and an honest comparison of the model's loss against the material's own published figure. A real B-H loop is measured, not derived, and this page says so.
- Common Mode Choke CalculatorCommon-mode inductance from turns and core, the leakage that is the only differential inductance the filter actually gets, the self-resonance above which the choke is a capacitor and attenuates nothing, and the flux the current imbalance puts in a core the load current was supposed to leave empty.
- Core Loss Calculator (Steinmetz)Pᵥ = k·fα·Bβ from a ferrite data sheet, times the effective core volume, with the copper loss and a temperature rise beside it — and, because this is where the factor-of-a-thousand errors live, an explicit statement of which units your three constants are in.
- CT Burden Resistor CalculatorSize the burden resistor on a split-core or toroidal current transformer so that full-scale primary current just fills your ADC's input swing — with the nearest standard value and what substituting it costs, the burden's own dissipation, and a saturation check against the CT's knee, because too large a burden makes the reading non-linear and low.
- Gapped Core Inductance CalculatorEffective permeability, Aₗ and inductance for an inductor wound on a gapped ferrite core — with the peak flux density against the material's saturation limit, which is the number that actually decides the design, the stored energy, and McLyman's fringing correction, which this page checks against a manufacturer's own published gapped Aₗ figures.
- Litz Wire and Skin Depth CalculatorSkin depth first, because that is the number everything else hangs on — then the strand diameter as a fraction of it, the strands you need for a given copper area, the bundle's DC resistance and outside diameter, and the AC-to-DC resistance ratio with the proximity term from Sullivan's litz formula.
- SMPS Transformer CalculatorSize a switch-mode transformer for a forward or flyback converter by the area-product method: the core area product Ap, primary and secondary turns for your core, wire gauges from the current density, the skin depth and, for a flyback, the air gap.
- Toroid Inductor Turns Calculator (AL Value)Turns for a target inductance on a ring core from its Aₗ value, both directions, with the flux-density check that decides whether the design works at your peak current, the Aₗ tolerance band the core is really built to, and whether the wire fits the window.
- Transformer Efficiency CalculatorEfficiency and voltage regulation for a mains transformer from the figures it is actually specified by — no-load loss, load loss and impedance voltage — with the load fraction at maximum efficiency, the leading-power-factor case where regulation goes negative, and all-day efficiency from a duty schedule.
- Transformer kVA to Current CalculatorFull-load current on both windings from a transformer's kVA rating — or the kVA from a measured current — plus the short-circuit current its percentage impedance allows at the terminals.
- Transformer Turns Ratio CalculatorTurns ratio, secondary voltage, current ratio, impedance ratio and volts per turn — solved whichever way round you have the numbers, with the losses and regulation the ideal formula leaves out.