Learn wireless power, with the numbers shown.
Reference articles on wireless power transfer and coil design. Each one answers a single question, shows the equations, works an example with real computed numbers and cites its sources.
Wireless power coil design guide
Designing a coil pair end to end: topology, size, turns, gap, k, Q, compensation, frequency, exposure limits and fabrication, with worked numbers.
Read article →CouplingCoupling coefficient k explained
What k is, how to compute it from geometry, representative values and how it falls with distance and misalignment.
Read article →CouplingMutual inductance: Neumann and Maxwell
The definition, the Neumann double integral, Maxwell’s elliptic-integral formula for coaxial loops and a worked example.
Read article →FieldHelmholtz coils: spacing and field
Why d = R for circular pairs and 0.5445·side for square pairs, the centre-field formulas and how uniform the field really is.
Read article →CircuitWPT compensation topologies: SS, SP, PS, PP, LCC
When to use each resonant network, the design equations, and frequency splitting and bifurcation.
Read article →CircuitWPT efficiency and the kQ figure of merit
η_max = U²/(1 + √(1 + U²))², why Q matters as much as k, skin depth and litz wire.
Read article →StandardsWireless charging standards and exposure limits
Qi, SAE J2954 and AirFuel Resonant frequencies and power classes, and the ICNIRP and IEEE C95.1 exposure limits.
Read article →MethodsBiot–Savart vs FEM for coil simulation
When a closed-form Biot–Savart solver is enough and when you need FEM or full-wave: ferrite, shields, eddy currents, self-resonance, SAR.
Read article →How these articles are built
Every number in a worked example is computed when the page renders, using the same closed-form physics as the free calculators: Maxwell’s elliptic-integral formula and the Neumann integral for mutual inductance, the Biot–Savart law for fields, and standard circuit results for compensation and efficiency. Change an input in the matching calculator and you get the same answer the article shows.
The articles are honest about limits. Closed-form results are exact for air-core coils in the magnetostatic regime; ferrite, shielding, eddy currents and self-resonance need other tools, as Biot–Savart vs FEM explains. See validation for how the solver is checked.
More ways to learn
- Learning Center: tutorials, workflows and case studies for AirInduct Sim.
- Coil topologies: the eight coil pairs AirInduct Sim solves, compared on one geometry.
- Free calculators: mutual inductance, coupling, Helmholtz, compensation and efficiency.
- WPT simulation software compared: when to use which tool.
Frequently asked questions
Who writes the Learn articles?
The AirInduct Sim engineering team. Every worked example is computed on the page with the same physics code as the free calculators, and every article lists its references: peer-reviewed papers, textbooks and the standards bodies themselves.
How is Learn different from the Learning Center?
Learn is a set of reference articles that answer one engineering question each, with equations, worked numbers and sources. The Learning Center is a curated path through tutorials, workflows and case studies for the AirInduct Sim product.
Can I cite these articles?
Yes. Each article states its assumptions and shows its formulas and inputs, so the numbers can be reproduced. For formal work, cite the primary references listed at the end of each article alongside the page.