E Family¶

The E family is the most common core shape family, with many variants for different applications.

Shapes¶

E - Standard E Core¶

The basic E-shaped core with rectangular cross-section legs.

Dimension	Description
A	Overall width
B	Overall height (one half)
C	Winding window height
D	Center leg height below window
E	Outer leg spacing
F	Center leg width

e_shape = {
    "family": "e",
    "name": "E 42/21/20",
    "dimensions": {
        "A": {"nominal": 0.042},
        "B": {"nominal": 0.021},
        "C": {"nominal": 0.0157},
        "D": {"nominal": 0.0145},
        "E": {"nominal": 0.0296},
        "F": {"nominal": 0.0142},
    }
}

Class hierarchy: E(IPiece)

ETD - E Core with Round Center Leg¶

E core variant where the center leg has a round cross-section, reducing winding length.

Dimensions: Same as E (A, B, C, D, E, F)

Class hierarchy: Etd(Er(E))

ER - E Core with Round Center¶

E core with a round center column. Base class for ETD, LP, EQ, EC.

Dimensions: A, B, C, D, E, F

Class hierarchy: Er(E)

EFD - E Core, Flat Design¶

Low-profile E core designed for flat transformers. Uses a modified winding window geometry.

Dimensions: A, B, C, D, E, F

Class hierarchy: Efd(E)

EC - E Core, Cylindrical¶

E core with a cylindrical center leg and modified outer legs.

Dimensions: A, B, C, D, E, F

Class hierarchy: Ec(Er)

EQ - E Core, Square¶

E core optimized for minimal air gap effects.

Dimensions: A, B, C, D, E, F

Class hierarchy: Eq(Er)

EP - E Core, Pot-Like¶

E core with a partially enclosed winding area, offering some shielding.

Dimension	Description
A	Overall width
B	Overall height
C	Winding window height
D	Base height
E	Outer dimension
F	Center leg dimension
G	Opening width
H	Additional height dimension

Class hierarchy: Ep(E)

EPX - E Core, Pot-Like Extended¶

Extended variant of EP with additional dimensional parameters.

Dimension	Description
A-H	Same as EP

Class hierarchy: Epx(E)

Generating an E-Family Core¶

from OpenMagneticsVirtualBuilder.builder import Builder
import copy

builder = Builder("CadQuery")

shape_data = {
    "family": "etd",
    "name": "ETD 49/25/16",
    "dimensions": {
        "A": {"nominal": 0.0492},
        "B": {"nominal": 0.0250},
        "C": {"nominal": 0.01720},
        "D": {"nominal": 0.01745},
        "E": {"nominal": 0.03780},
        "F": {"nominal": 0.01650},
    }
}

geo_desc = [
    {"type": "half set", "shape": copy.deepcopy(shape_data),
     "rotation": [0, 0, 0], "coordinates": [0, 0], "machining": None},
    {"type": "half set", "shape": copy.deepcopy(shape_data),
     "rotation": [3.14159265359, 0, 0], "coordinates": [0, 0], "machining": None},
]

step_path, stl_path = builder.get_core("ETD49", geo_desc, output_path="./output/")