MAS Glossary

Informative. This glossary defines the terms used across the MAS JSON Schema and its accompanying documents. It is a reading aid; the normative definitions are the schema description fields and the standards mapping in normative-references.md. Where a term has a citation in the IEC International Electrotechnical Vocabulary (IEV) or another standard, the reference follows the definition in parentheses.

Field names are written in camelCase to match the schema; concept names that are not literal property keys are written in plain prose.

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Components and Geometry

Term	Definition
core	Magnetic core providing the magnetic circuit path (IEV 221-04-24).
coil	Wound assembly of one or more windings on a former. MAS uses the term in the broad industry sense; the strict IEV sense is in IEV 151-13-15.
winding	Assembly of interconnected turns intended for common operation (IEV 151-13-17).
turn	One closed loop of conductor (IEV 151-13-14).
bobbin	Insulating former on which one or more windings are arranged. Industry term; not yet in IEV (PSMA queue).
layer	Group of physical turns wound side-by-side in one radial position.
section	Group of layers belonging to the same winding or grouped for interleaving.
group	Collection of sections, typically used for distinct winding windows or PCB sub-assemblies.
partialWinding	Subset of a winding by proportion of turns or proportion of parallels.
parallel	Conductor connected in parallel with others to carry a fraction of one electrical turn's current.
windingWindow	Space available for placing turns of windings within the core.
column	Vertical or axial section of the core with a defined cross-section.
pin	Connection point on the bobbin where a winding terminates.
coordinates	Positional values (cartesian, polar, or cylindrical) used to place geometry features.

Core Construction Families

Term	Definition
twoPieceSet	Core assembled from two mating pieces (E, ETD, PQ, RM, etc.).
pieceAndPlate	Core assembled from one shaped piece and a flat plate.
toroidal	Single closed-ring core (IEV 221-04-24, ring core).
closedShape	Single-piece closed-magnetic-path core that is not toroidal (e.g. pot core).
shape	Geometric form of the core (E, ETD, ER, EFD, PQ, RM, T, EP, …).
numberStacks	Number of identical cores stacked along the axis perpendicular to the lamination plane.
coating	Surface treatment of the core (e.g. epoxy, parylene).

Air Gap

Term	Definition
gapping	List of air gaps introduced into the magnetic circuit (IEV 221-04-13).
gap / airGap	Intentional or residual break in the magnetic core path.
subtractive gap	Material removed from the core (e.g. centre-leg ground gap).
additive gap	Spacer inserted between mating surfaces, increasing the assembled core height.
residual gap	Unavoidable gap at mating surfaces of an ungapped two-piece set.
distributed gap	Air distributed throughout the magnetic path (e.g. powder cores).

Magnetic Quantities

Term	Definition
magneticFluxDensity	Magnetic flux density B, in tesla (T).
magneticFieldStrength	Magnetic field strength H, in ampere per metre (A/m).
magnetizingInductance	Inductance associated with the magnetising current; the design-target inductance of the component.
leakageInductance	Inductance from flux that does not link all turns of the coupled winding.
permeability	Relative permeability of the material; reported as initial, amplitude, incremental, reversible, or complex.
saturation	BH-curve points characterising saturation flux density; by convention reported where the relative differential permeability has fallen to 10 % of the initial permeability.
remanence	Residual flux density when the applied field is zero (BH-cycle point).
coerciveForce	Field strength required to reduce flux density to zero (BH-cycle point).
bhCycle	Complete B–H hysteresis loop characterising the material.
effectiveLength	Equivalent magnetic path length per IEC 60205 / IEC 63182.
effectiveArea	Equivalent cross-sectional area perpendicular to the flux path per IEC 60205 / IEC 63182.
effectiveVolume	Product of effective length and effective area; the magnetised volume.
minimumArea	Minimum cross-sectional area along the flux path.

Electrical and Waveform

Term	Definition
current	Electrical current through a winding, in amperes (A).
voltage	Electrical voltage across a winding, in volts (V).
frequency	Operating frequency of the waveform, in hertz (Hz).
dutyCycle	Fraction of the period during which the signal is in its active state (0–1).
deadTime	Interval after Ton and Toff in switching waveforms, in seconds.
peakToPeak	Difference between the maximum and minimum values of the waveform.
peak	Maximum absolute value of the waveform.
positivePeak	Maximum positive value of the waveform.
negativePeak	Most-negative value of the waveform (≤ 0 for bipolar signals).
rms	Root-mean-square value of the periodic waveform.
average	Mean value of the waveform over one period.
offset	DC component of the waveform.
phase	Phase angle of the waveform, in degrees.
harmonics	Frequency components of a complex waveform (amplitudes and frequencies).
thd	Total harmonic distortion of the waveform.
effectiveFrequency	Equivalent sinusoidal frequency producing the same RMS rate of change (per IEEE 750181 Appendix C).
waveform	Sample-based representation of an arbitrary waveform.
processed	Higher-level descriptor of a waveform from which the waveform itself can be reconstructed.
waveformLabel	Common waveform shape (triangular, rectangular, sinusoidal, flybackPrimary, flybackSecondary, custom, …).
bias	DC component superimposed on an AC excitation.

Operating Conditions

Term	Definition
operatingPoint	A complete operating state: conditions plus excitations on every winding.
operatingConditions	Ambient and cooling parameters that apply to one operating point.
excitation	Per-winding signal description (frequency, current, voltage, flux density, field strength, magnetising current).
ambientTemperature	Ambient temperature at the operating point, in degrees Celsius.
ambientRelativeHumidity	Ambient relative humidity, as a fraction 0–1.
cooling	Heat-dissipation arrangement: naturalConvection, forcedConvection, heatsink, or coldPlate.
outputVoltagesType	How values in outputVoltages are interpreted (dc, rms, peak, peakToPeak, average); defaults to dc.
outputCurrentsType	How values in outputCurrents are interpreted; same enum and default as above.

Wire

Term	Definition
wire	Conductor used to form turns and windings.
round	Single solid circular conductor.
litz	Stranded wire of individually insulated round strands twisted together to mitigate skin and proximity effects.
rectangular	Solid conductor of rectangular cross-section.
foil	Solid flat conductor with specified width and height.
planar	Spiral conductor patterned on a PCB layer.
numberConductors	Count of separate conductors in a multi-strand wire.
strand	One round conductor in a litz bundle.
twistPitch	Length of one full twist of a litz bundle along the wire axis.
outerDiameter	Overall diameter including insulation.
conductingArea	Cross-sectional area of conducting material (rounded corners accounted for).
conductingWidth	Width of the conducting region (foil, rectangular).
conductingHeight	Height of the conducting region (foil, rectangular).
standard	Wire specification standard (IEC 60317, NEMA MW 1000 C, IPC-6012).

Materials

Term	Definition
material	Magnetic material composition family (ferrite, powder, nanocrystalline, amorphous, electricalSteel).
materialComposition	Detailed make-up (MnZn, NiZn, FeSiAl, FeSi, FeNi, FeNiMo, FeMo, carbonylIron, iron).
resistivity	Volume resistivity per IEC 60093, in Ω·m.
density	Mass per unit volume, in kg/m³.
curieTemperature	Temperature above which a ferromagnetic material loses its ferromagnetism.
heatConductivity	Thermal conductivity, in W/(m·K).
heatCapacity	Specific heat capacity, in J/(kg·K).

Insulation and Safety

Term	Definition
insulationType	Insulation classification per IEC 60664-1 §4.1: functional, basic, supplementary, double, reinforced.
temperatureClass	Insulation thermal class per IEC 60085 (Y/A/E/B/F/H/N/R/200/220/250).
dielectricStrength	Field strength at which insulation breaks down, in V/m.
relativePermittivity	Dielectric constant of the insulation material.
creepageDistance	Shortest path along an insulation surface between two conductive parts (IEC 60664-1).
clearance	Shortest straight-line distance through air between two conductive parts (IEC 60664-1).
cti	Comparative tracking index group per IEC 60112: groupI, groupII, groupIIIA, groupIIIB.
pollutionDegree	Pollution level per IEC 60664-1 §4.2: PD1, PD2, PD3, PD4.
overvoltageCategory	Overvoltage category per IEC 60664-1 §4.3: I, II, III, IV.
surfaceResistivity	Surface resistivity per IEC 60093, in Ω/sq.
meltingPoint	Temperature at which the insulation material melts, in degrees Celsius.
interlayerInsulation	Insulation barrier placed between adjacent layers of a winding.
marginInfo	Margin tape at the extremes of a section, used to enforce creepage.

Topology and Application

Term	Definition
topology	Converter topology for which the magnetic is designed (e.g. buckConverter, flybackConverter, llcResonantConverter, dualActiveBridgeConverter, commonModeChoke).
application	Primary application: power, signalProcessing, or interferenceSuppression.
subApplication	Sub-application: powerFiltering, transforming, isolation, commonModeNoiseFiltering, differentialModeNoiseFiltering.
wiringTechnology	Construction method: wound, printed, stamped, deposition.
market	Target market: commercial, industrial, medical, military, space.

Losses and Efficiency

Term	Definition
coreLosses	Total power dissipated in the core, in watts.
hysteresisCoreLosses	Component of core loss attributed to hysteresis.
eddyCurrentCoreLosses	Component of core loss attributed to induced eddy currents.
volumetricLosses	Core loss per unit volume, in W/m³.
massLosses	Core loss per unit mass, in W/kg.
windingLosses	Power dissipated in the winding conductors, in watts.
steinmetz	Empirical core-loss model, P = k · fα · Bβ.
roshen	Roshen core-loss model accounting for excess losses.
skinEffect	Tendency of AC current to concentrate near the conductor surface, raising effective resistance.
proximityEffect	Eddy currents induced in a conductor by the field of nearby conductors, raising effective resistance.
fillingFactor	Fraction of available winding-window area occupied by conductor.
thermalResistance	Steady-state temperature rise per dissipated power, in K/W.
temperatureRise	Steady-state temperature increase above ambient, in kelvins.

Coil Construction

Term	Definition
numberTurns	Total number of turns in a winding.
numberParallels	Number of conductors connected in parallel to form one electrical turn.
isolationSide	Label grouping windings that share a common ground reference (primary, secondary, tertiary, …).
woundWith	Names of other windings physically wound together (e.g. bifilar, IEV 151-13-18).
connectionType	Terminal style: pin, screw, smt, flyingLead, tht, pcbPad.
bobbinFamily	Core-shape family the bobbin is designed for (u, e, etd, er, p, rm, ep, pm, el, pq, efd, ec, t).
wallThickness	Thickness of the bobbin walls confining the wire on the column sides.
columnThickness, columnDepth, columnWidth	Dimensions of the bobbin's central column.

Standards Metadata

Term	Definition
manufacturerInfo	Manufacturer-supplied identification for a part.
distributorInfo	Distributor-supplied identification, stocking, and price information for a part.
cost	Monetary value with explicit currency: { value, currency } where currency is an ISO 4217 three-letter code.
irdi	International Registration Data Identifier per ISO/IEC 11179-6 / ISO 29002-5, in the form RAI#DI#VI.
datasheetInfo	Catalogue-level data extracted directly from the manufacturer's datasheet.
status	Production status: production, prototype, obsolete.

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See also

• normative-references.md — full mapping to IEC, IEV, ISO, IEEE, NEMA, JIS, MPIF, ASTM standards.
• units.md — normative unit table.
• schema.md — schema structure and required-field reference.
• quickref.md — quick reference for common patterns.

Provenance (data-source trail)

Every datasheetInfo carries an optional provenance array recording where its data came from. Optional and closed, so records without it remain valid. Each entry:

field	meaning
source	manufacturerDatasheet · manufacturerParametric · manufacturerDatabase · distributor · librarianEnrichment · scrape · manual
sourceName	human-readable source, e.g. "TI parametric API", "WE - Passive Components.mdb", "DigiKey"
sourceUrl	URL the value came from (optional)
retrievedDate	YYYY-MM-DD (optional)
fields	which datasheetInfo fields this source supplied — for mixed-source records (optional)

It is a list: a record may combine sources (e.g. specs from the datasheet, a rated voltage from a distributor, a missing field back-filled by librarian enrichment). The canonical definition lives in PEAS/schemas/utils.json#/$defs/provenance (aliased by MAS/schemas/utils.json via $ref, as are the other shared definitions such as dimensionWithTolerance).