Encyclopedia Magnetica

Encyclopedia of magnetics and electromagnetics.

User Tools

Site Tools


etd

Differences

This shows you the differences between two versions of the page.

Link to this comparison view

Both sides previous revision Previous revision
Next revision
Previous revision
etd [2015/01/08 14:10]
Dr Stan Zurek review
etd [2019/06/03 18:29] (current)
Line 1: Line 1:
-====== ETD ======+==== ETD ====
  
-|< 100% >| +see => **[[ETD ferrite core]]**
-| //​[[user/​Stan Zurek]], ETD, [[http://​Encyclopedia-Magnetica.com|Encyclopedia-Magnetica.com]],​ {accessed @YEAR@-@MONTH@-@DAY@}//​ | +
-| //​[[/​wiki/​reviewed]] by [[user/Jeff Jones]], 2015-01-07//​ | +
- +
-**ETD** (//​**E**conomic **T**ransformer **D**esign//​[(Epcos>​[[http://​www.epcos.com/​web/​generator/​Web/​Sections/​ProductCatalog/​Ferrites/​EFDEVCores/​PDF/​PDF__ECores,​property=Data__en.pdf;/​PDF_ECores.pdf|Ferrites and accessories,​ E cores, General information,​ Epcos, Sep 2006, p. 2, {accessed 28 Feb 2013}]])]) - a name of commonly used family of [[ferrite core|ferrite cores]] for [[transformer|transformers]],​ [[inductor|inductors]],​ [[choke|chokes]] and [[electronic lamp ballast device|electronic lamp ballast devices]].[(Epcos-2013>Epcos Data Book 2013, Ferrites and Accessories,​ TDK, http://​www.epcos.com {accessed 18 Nov 2013})] +
-  +
-The dimensions of ETD sets are defined in industry and international standards like [[IEC 61185]] and [[IEC 60424]]. +
- +
-<WRAP 30% right> +
-<box 90% left #​f0f0f0>​ +
-ETD core halves ([[ETD49]]) +
-[[file/​ETD49 3C95 Magnetica.jpg|{{ETD49 3C95 Magnetica.jpg}}]] +
-{{page>​insert/​by_SZ}} +
-</​box>​ +
-<box 90% left #​f0f0f0>​ +
-The outer [[limb|limbs]] of ETD core halves have concave shapes[([[http://​www.epcos.com/​inf/​80/​db/​fer_07/​etd_59_31_22.pdf|ETD 59/31/22 Core and accessories,​ Epcos, December 2008, {accessed 4 Nov 2013}]])] +
-[[file/​ETD59 drawing Magnetica.png|{{ETD59 drawing Magnetica.png}}]] +
-{{page>​insert/​by_SZ}} +
-</​box>​ +
-</​WRAP>​ +
- +
-===== Naming convention ===== +
- +
-There are several sizes in the ETD series, from [[ETD19]] to [[ETD59]].[(TDK>​[[http://​www.tdk-components.de/​pdfs/​ferrite/​ferrites-products/​etd_cores.pdf|ETD Series, TDK, {accessed 28 Feb 2013}]])][(Ferroxcube>​[[http://​www.ferroxcube.com/​prod/​assets/​etd_frnt.pdf|Soft ferrites, ETD cores and accessories,​ Ferroxcube, {accessed 28 Feb 2013}]])] +
-The number denotes the width of the [[E core|"​E"​ part]] in millimetres,​ so for instance [[ETD44]] core is around 44 mm wide (disregarding mechanical tolerances). +
- +
-The full names include further numbers, defining width, length, and thickness of the core half, respectively. Since the dimensions are standardised usually only the first to digits are used for description,​ eg. just "​[[ETD59]]"​ instead of the full "​[[ETD59-31-22|ETD59/​31/​22]]"​. +
- +
-  ​[[ETD19]] => [[ETD19-14-8|ETD19/​14/​8]] [(TDK)][(Kaschke>​[[http://​www.kaschke.de/​en/​products/​ferrites/​etd-and-er-cores|ETD and ER cores, Kaschke, {accessed 12 Nov 2013}]])] +
-  ​* [[ETD24]] => [[ETD24-15-9|ETD24/​15/​9]] [(TDK)][(Kaschke)] +
-  * [[ETD29]] => [[ETD29-16-10|ETD29/​16/​10]] [(TDK)][(Ferroxcube)] +
-  * [[ETD34]] => [[ETD34-17-11|ETD34/​17/​11]] [(TDK)][(Ferroxcube)] +
-  * [[ETD39]] => [[ETD39-20-13|ETD39/​20/​13]] [(TDK)][(Ferroxcube)] +
-  * [[ETD44]] => [[ETD44-22-15|ETD44/​20/​15]] [(TDK)][(Ferroxcube)] +
-  * [[ETD49]] => [[ETD49-25-16|ETD49/​25/​16]] [(TDK)][(Ferroxcube)] +
-  * [[ETD54]] => [[ETD54-28-19|ETD54/​28/​19]] [(TDK)][(Ferroxcube)] +
-  * [[ETD59]] => [[ETD59-31-22|ETD59/​31/​22]] [(Ferroxcube)] +
- +
-===== Size and shape ===== +
- +
-The ETD cores are normally assembled of two identical [[core half|halves]]. When [[assembly|assembled]],​ the outline of the core is almost square. +
- +
-<box 30% left #​f0f0f0>​ +
-[[Horizontal bobbin|Horizontal bobbins]]: [[ETD54]], [[ETD49]], [[ETD44]], [[ETD39]], [[ETD34]] and [[ETD29]]  +
-[[file/​ETD_horizontal_bobbins_magnetica.jpg|{{ETD_horizontal_bobbins_magnetica.jpg}}]] +
-{{page>​insert/​by_SZ}} +
-</​box>​ +
- +
-The central [[limb]] of the core has a circular cross-section. This allows having the smallest possible [[turn length]] and thus reduces the [[copper loss]] as compared to cores with rectangular area - hence the name "​economic"​. Additionally,​ the outer limbs have characteristic concave shapes so as to accommodate a coil with greater outer diameter (than it would be possible for a simple rectangular core). +
- +
-The ETD geometry gives a good compromise between the volume of ferrite ​(pertinent to [[core loss]]), the volume of copper (copper loss) and surface area ([[thermal resistance]]). The additional benefit is that the core has almost constant cross-section area along the magnetic path.[(Epcos)] As a result, the core volume is magnetised in a more uniform way and the [[core weight]] is optimised. +
- +
-The [[ETD]] part description (ETD19/14/8 for example) defines only the cores physical size, the actual cores may be constructed from one of several different types of magnetically soft ferrite ​ material, the material would be selected to suite a particular application,​ operating frequency, cooling requirements etc. +
- +
-If an [[air gap]] is required then it should be made in the central leg of the core, for all E-type cores this assures optimum performance. Some manufacturers provide standardised gap lengths (e.g 0.2 mm or 0.5 mm). For smaller gaps thin shims can be inserted in the side legs.[([[http://​www.ti.com/​lit/​ml/​slup198/​slup198.pdf|Lloyd Dixon, Deriving the equivalent electrical circuit from the magnetic device physical properties, Texas Instruments,​ 2003, {accessed 18 Nov 2013}]])] +
- +
-===== Bobbins and clips ===== +
- +
-<box 30% right #​f0f0f0>​ +
-[[Vertical bobbin]] ETD  +
-[[file/​etd_vertical_bobbin_magnetica.jpg|{{etd_vertical_bobbin_magnetica.jpg}}]] +
-{{page>​insert/​by_SZ}} +
-</​box>​ +
- +
-Different manufacturers use various approaches to the bobbins and retaining clips. In some versions the clips hold the core halves to the bobbin. In others, the clip holds the core halves together without touching the bobbin. +
- +
-Also, there are available [[horizontal bobbin|horizontal]] and [[vertical bobbin|vertical]],​ as well as [[split bobbin|split bobbins]] (multiple parts). +
- +
-The bobbins can be supplied without pins, as well as partially or fully pinned, with square or round pins. Partial pinning might be useful for so that the bobbin will fit into a PCB only one way thus avoiding assembly mistakes. +
- +
-===== Practical use ===== +
-Most manufacturers of [[magnetically soft ferrite|magnetically soft ferrites]] used for energy conversion applications produce ETD cores. These manufactures will typically produce ETD core accessories such as bobbins and the core retaining clips. +
- +
-The ETD cores are widely used for transformers and inductors in higher power applications like power supplies +
-[(Marko Scherf, Wolfgang Frank, Application Note AN-CoolMOS-09,​ 200W SMPS Demonstration Board II, Infineon Technologies AG, September 2004, http://​www.infineon.com {accessed 14 Nov 2013})][([[http://​www.onsemi.com/​pub_link/​Collateral/​AND8281-D.PDF|Joel Turchi, AND8281/D, Implementing the NCP1605 to drive the PFC stge of a 19V / 8A power supply, ON Semiconductor,​ Jan 2007, {accessed 14 Nov 2013}]])][(Sanjaya Maniktala, Switching power supplies A-Z, 2nd edition, Newnes, 2012, ISBN 978-0-12-386533-5)][(Colonel William T. McLyman, Transformer and Inductor Design Handbook, CRC Press, 2004, ISBN 9780824751159)] from tens to thousands of [[watt|watts]].[(Epcos-2013)] +
- +
-However, the ETD cores offer less [[magnetic shielding]] in configuration with a large gap. In such cases [[distributed air gap]] or toroidal [[powder core|powder cores]] can be more effective. +
- +
-===== Gallery of photos ===== +
- +
-<box 30% left #​f0f0f0>​ +
-[[Ferrite]] [[transformer]] [[ETD44]] +
-[[file/​Transformer ETD44 160W Magnetica.jpg|{{Transformer ETD44 160W Magnetica.jpg}}]] +
-{{page>​insert/​by_SZ}} +
-</​box>​ +
-<box 30% left #​f0f0f0>​ +
-Ferrite transformer [[ETD29]] +
-[[file/​ETD29 transformer Magnetica.jpg|{{ETD29 transformer Magnetica.jpg}}]] +
-{{page>​insert/​by_SZ}} +
-</​box>​ +
-<box 30% left #​f0f0f0>​ +
-Disassembled transformer [[ETD29]]  +
-[[file/​ETD29 disassembled Magnetica.jpg|{{ETD29 disassembled Magnetica.jpg}}]] +
-{{page>​insert/​by_SZ}} +
-</​box><​WRAP clear></​WRAP>​ +
-<box 30% left #​f0f0f0>​ +
-[[Gapped core]] ETD49, material [[3C90]]  +
-[[file/ETD core gapped Magnetica.jpg|{{ETD core gapped Magnetica.jpg}}]] +
-{{page>​insert/​by_SZ}} +
-</​box>​ +
-<box 30% left #​f0f0f0>​ +
-[[Flux band]] on a [[vertical bobbin|vertical]] ETD transformer  +
-[[file/​Transformer flux band Magnetica.jpg|{{Transformer flux band Magnetica.jpg}}]] +
-{{page>​insert/​by_SZ}} +
-</​box>​ +
- +
-===== See also ===== +
-  ​[[EFD]] (economic flat design) +
-  ​[[ER]] (planar cores) +
-  * [[EQ]] +
- +
-===== References ===== +
-~~REFNOTES~~ +
- +
-{{tag>​ETD Counter}}+
  
 +{{tag>​Redirects}}
etd.txt · Last modified: 2019/06/03 18:29 (external edit)

Privacy and cookie policy (GDPR).