Shape Catalog

MVB supports 21 magnetic core shape families following the EN 60205 standard naming convention.

Families at a Glance

Family	Shapes	Typical Application
E Family	E, ETD, ER, EFD, EC, EQ, EP, EPX	General purpose, power supplies
P Family	P, PQ, PM, RM	Shielded, low EMI
Planar	PLANAR_E, PLANAR_ER, PLANAR_EL, LP	Low profile, PCB-mount
U Family	U, UR, UT	High power, chokes
Toroidal	T	EMI filters, current sensors
C Cores	C	High power, adjustable gap

Dimension Naming Convention

All shapes use single-letter dimensions from EN 60205:

Letter	Typical Meaning
A	Overall width (largest horizontal dimension)
B	Overall height of one half
C	Winding window height
D	Center leg height (below winding window)
E	Center leg width or outer leg spacing
F	Center leg depth / diameter
G	Shape-specific (EP/EPX pot opening, P inner dims)
H	Shape-specific (EP/EPX height details, P inner dims)
J	Shape-specific (RM family only)

Note

Not all dimensions apply to every shape. For example, toroidal cores only need A (outer diameter), B (inner diameter), and C (height).

MAS Dimension Format

Dimensions in MAS data can be specified three ways:

// Plain number
"A": 0.042

// Nominal value
"A": {"nominal": 0.042}

// Min/max range
"A": {"minimum": 0.041, "maximum": 0.043}

The flatten_dimensions() function resolves all formats to a single value.

Listing Families Programmatically

from OpenMagneticsVirtualBuilder.builder import Builder

builder = Builder("CadQuery")
families = builder.get_families()

for name, subtypes in families.items():
    print(f"{name}:")
    for subtype, dims in subtypes.items():
        print(f"  Subtype {subtype}: {dims}")