EER42,ETD-core,EER-core,EER40,EER20,EER35,EER cores,EER28,EER30,EER34,EER43,EER45,EER50,ETD cores,

HOME

PRODUCTS

PROFILE

CONTACT

SITEMAP

CATALOG

p

EER CORES

ETD CORES

Description of the “E” patterns

The "E" patterns are sought that are easy to assemble, could be interleave to minimize gap effects, and would

minimize waste. Since “E” cores have two open coil sides, they provide substantial room to bring high current

lead wires out from the coil. It is easier to achieve high voltage electrical isolation with an “E” core. In the typical

“E” lamination, the center leg (one of three legs) is twice the width of either outer leg. In theory, magnetic flux

flowing out of the center leg divides equally and flows into the outer two "E" core legs. Since the outer legs

handle half the flux they only need to have half the cross-section that the center leg has. It is easier to achieve

high voltage electrical isolation with an “E” core than with a pot core.

Presentation of EER-core and ETD-core

EER-core and ETD-core are examples of type “E” cores with round center legs. The combined cross section of the

two outer legs of EER cores and ETD cores should equal or exceed that of the center leg. The core stack is a

stack of laminations and the typical stack has core legs of rectangular cross-section. Typically the inductor or

transformer coil is placed over the center core leg. To minimize winding resistance (hence also minimize winding

losses) it is desirable to have a round center leg. A round center leg also eliminates the sharp bend encountered

when winding wire around a rectangular leg; consequently a round center leg permits use of larger wire.

Achieving round center legs with laminations is possible but very impractical. With the development of powdered

cores and ferrite cores it became practical to have a round center leg. EER-core and ETD-core type, such as

EER42, EER40, EER20, EER35, EER28, EER30, EER34, EER43, EER45, EER50, etc, ferrite cores are developed for

higher power higher frequency switching transformers.

Application of EER-core and ETD-core

EER cores and ETD cores are usually larger, but have a wide winding area, which makes them particularly good

for higher power designs or multiple output designs. Remember a larger core size will be needed for a margin

wound type transformer than for a triple insulated type to allow room for the margins. EER cores with round

center leg offer ideal features for the design of SMPS transformers chokes. We offer various EER cores and ETD

cores, including EER42, EER40, EER20, EER35, EER28, EER30, EER34, EER43, EER45, EER50, EER49, EER25.5,

EER55, EER54, EER53, ETD29, ETD34, ETD39, ETD49, ETD44, ETD10, ETD41, ETD32, ETD59, ETD31, and

ETD22. Please find our details of ETD-core and EER-core by types and dimensions data shown as below.

Type

Dimensions(mm)

A

B

C

D

E

F

EER25

25.3±0.6

9.3±0.3

7.5 ± 0.3

7.5 ± 0.3

19.8

6.2 ± 0.3

EER28A

28.5±0.6

14.0 ± 0.3

11.4 ± 0.3

9.9±0.3

21.2

9.6±0.3

EER28B

28.5±0.6

16.9 ± 0.3

11.4 ± 0.3

9.9 ± 0.3

21.2

12.5 ± 0.3

ETD29

29.8±0.8

15.8 ± 0.2

9.5 ± 0.3

9.5 ± 0.3

22.0

11.0 ± 0.3

EER30

30.0 ± 0.8

17.5 ± 0.3

11.2 ± 0.3

9.9 ± 0.3

22.5

12.6 ± 0.3

ETD34

34.2 ± 0.8

17.3 ± 0.2

10.8 ± 0.3

10.8 ± 0.3

25.6

12.1 ± 0.3

EER35A

35.0 ± 0.7

21.0 ± 0.3

11.3 ± 0.4

11.3 ± 0.3

25.3

15.0 ± 0.3

EER35/34B

35.0 ± 0.7

16.8 ± 0.3

11.3 ± 0.4

11.3 ± 0.3

25.3

10.8 ± 0.3

EER35C

36.0 ± 0.7

21.6 ± 0.4

11.3 ± 0.4

11.3 ± 0.4

26.5

15.6 ± 0.4

EER37

36.0 ± 0.6

20.7 ± 0.3

11.3 ± 0.3

11.3 ± 0.3

27.6

14.7 ± 0.3

ETD39

39.1 ± 0.9

19.8 ± 0.2

12.6 ± 0.4

12.5 ± 0.3

29.3

14.6 ± 0.4

EER40A

40.0 ± 0.8

22.4 ± 0.3

13.3 ± 0.3

13.3 ± 0.3

29.0

15.4 ± 0.3

EER40B

44.0 ± 0.8

22.4 ± 0.3

13.3 ± 0.3

13.3 ± 0.3

29.3

15.4 ± 0.3

EER40C

40.0± 0.7

22.9 ± 0.3

13.3 ± 0.3

13.3 ± 0.3

29.5

15.9 ± 0.3

EER40D

40.2± 0.5

21.4± 0.3

15.5± 0.3

15.5± 0.3

29.4

15.4± 0.3

EER40E

-0.5

23.0± 0.3

13.3± 0.3

13.3± 0.3

29.0

16.0± 0.3

EER40F

41.0max

22.8±0.3

13.3±0.4

13.3±0.3

29.5

15.8±0.3

EER40G

-0.5

21.3±0.2

15.0±0.2

14.0±0.25

30.7

15.3±0.2

EER40H

41.0±0.7

- 0

-0.3

-0.3

30.0

-0

EER49A

49.0 ±0.8

26.2 ±0.4

17.0 ±0.5

17.0 ±0.5

36.5

-0.2

EER49B

49.0 ±1.0

27.0 ±0.3

17.2 ±0.4

17.2 ±0.3

36.5

18.7 ±0.3

ETD49

49.0 ±1.0

24.7 ±0.3

16.3 ±0.4

16.3 ±0.4

36.1

18.1 ±0.4

EER50

50.5 ±0.8

27.0 ±0.3

18.7 ±0.4

18.7 ±0.4

38.0

18.7 ±0.3

EER53

53.2 ±0.8

23.2 ±0.3

21.5 ±0.3

-0.3

38.7

16.3 ±0.3

EER54

54.2 ±0.8

25.1 ±0.4

18.9 ±0.4

18.9 ±0.3

40.5

17.5±0.3

EER55A

56.0 ±0.8

30.7 ±0.3

20.4 ±0.3

20.4 ±0.3

44.0

22.9±0.3

EER55B

55.9 ±1.0

29.0 ±0.3

24.3 ±0.5

20.2 ±0.3

43.5

20.4±0.3

Copyright 2005 YUXIANG Magnetic Materials Ind. Co.,Ltd.All Rights Reserved.

Add:16F1,jinyuan building,NO.57,hubin S.Rd.,Xiamen,China.361004

Tel : (86)592 2225286 (86)592 2219816 (86)592 2217138 Fax: (86)592 2207122

Email : yingli@magnets.com.cn yuxiang@sohu.net