This article was downloaded by: 10.3.98.104 On: 27 Sep 2021 Access details: subscription number Publisher: CRC Press Informa Ltd Registered in England and Wales Registered Number: 1072954 Registered office: 5 Howick Place, London SW1P 1WG, UK Transformer and Inductor Design Handbook Colonel Wm. T. McLyman Magnetic Cores Publication details https://www.routledgehandbooks.com/doi/10.1201/b10865-4 Colonel Wm. T. McLyman Published online on: 26 Apr 2011 How to cite :- Colonel Wm. T. McLyman. 26 Apr 2011, Magnetic Cores from: Transformer and Inductor Design Handbook CRC Press Accessed on: 27 Sep 2021 https://www.routledgehandbooks.com/doi/10.1201/b10865-4 PLEASE SCROLL DOWN FOR DOCUMENT Full terms and conditions of use: https://www.routledgehandbooks.com/legal-notices/terms This Document PDF may be used for research, teaching and private study purposes. Any substantial or systematic reproductions, re-distribution, re-selling, loan or sub-licensing, systematic supply or distribution in any form to anyone is expressly forbidden. The publisher does not give any warranty express or implied or make any representation that the contents will be complete or accurate or up to date. The publisher shall not be liable for an loss, actions, claims, proceedings, demand or costs or damages whatsoever or howsoever caused arising directly or indirectly in connection with or arising out of the use of this material. Chapter 3 Magnetic Cores 3-1 Downloaded By: 10.3.98.104 At: 07:25 27 Sep 2021; For: 9781439836880, chapter3, 10.1201/b10865-4 © 2011 by Taylor and Francis Group, LLC 3-2 Magnetic Cores Table of Contents 1. Introduction ...........................................................................................................................................3-4 2. Core Type and Shell Type Construction .............................................................................................3-5 3. Types of Core Materials .......................................................................................................................3-5 4. Eddy Currents and Insulation .............................................................................................................3-6 5. Laminations ...........................................................................................................................................3-7 6. Annealing and Stress-Relief ................................................................................................................3-8 7. Stacking Laminations and Polarity ....................................................................................................3-9 8. Flux Crowding ......................................................................................................................................3-10 9. Exciting Current ...................................................................................................................................3-11 10. Tape Wound C, EE, and Toroidal Cores ............................................................................................3-12 11. Tape Toroidal Cores .............................................................................................................................3-14 12. Toroidal, Powder Core .........................................................................................................................3-15 13. Stacking Factors....................................................................................................................................3-15 14. Introduction to the Magnetic Cores ....................................................................................................3-16 15. Design and Dimensional Data for EI Laminations ...........................................................................3-17 16. Design and Dimensional Data for UI Laminations ...........................................................................3-18 17. Design and Dimensional Data for LL Laminations ..........................................................................3-19 18. Design and Dimensional Data for DU Laminations ..........................................................................3-20 19. Design and Dimensional Data for Three-Phase Laminations ..........................................................3-21 20. Design and Dimensional Data for Tape Wound C Cores .................................................................3-22 21. Dimensional Outline for Tape Wound EE Cores...............................................................................3-23 22. Design and Dimensional Data for Tape Wound Toroidal Cores ......................................................3-24 23. Design and Dimensional Data for EE Ferrite Cores .........................................................................3-25 24. Design and Dimensional Data for EE and EI Planar, Ferrite Cores ...............................................3-26 25. Design and Dimensional Data for EC, Ferrite Cores ........................................................................3-27 26. Design and Dimensional Data for ETD, Ferrite Cores .....................................................................3-28 27. Design and Dimensional Data for ETD/(low profile), Ferrite Cores ................................................3-29 28. Design and Dimensional Data for ER, Ferrite Cores ........................................................................3-30 29. Design and Dimensional Data for EFD, Ferrite Cores .....................................................................3-31 30. Design and Dimensional Data for EPC, Ferrite Cores .....................................................................3-32 31. Design and Dimensional Data for PC, Ferrite Cores ........................................................................3-33 32. Design and Dimensional Data for EP, Ferrite Cores .........................................................................3-34 33. Design and Dimensional Data for PQ, Ferrite Cores ........................................................................3-35 Downloaded By: 10.3.98.104 At: 07:25 27 Sep 2021; For: 9781439836880, chapter3, 10.1201/b10865-4 © 2011 by Taylor and Francis Group, LLC Table of Contents 3-3 34. Design and Dimensional Data for PQ/(low profile), Ferrite Cores ..................................................3-36 35. Design and Dimensional Data for RM, Ferrite Cores .......................................................................3-37 36. Design and Dimensional Data for RM/(low profile), Ferrite Cores .................................................3-38 37. Design and Dimensional Data for DS, Ferrite Cores ........................................................................3-39 38. Design and Dimensional Data for UUR, Ferrite Cores.....................................................................3-40 39. Design and Dimensional Data for UUS, Ferrite Cores .....................................................................3-41 40. Design and Dimensional Data for Toroidal, Ferrite Cores ...............................................................3-42 41. Design and Dimensional Data for Toroidal, MPP Powder Cores ....................................................3-43 42. Design and Dimensional Data for Toroidal, Iron Powder Cores .....................................................3-44 43. Design and Dimensional Data for Toroidal, Sendust Powder Cores ...............................................3-45 44. Design and Dimensional Data for Toroidal, High Flux Powder Cores ...........................................3-46 45. Design and Dimensional Data for EE, Iron Powder Cores...............................................................3-47 46. Design and Dimensional Data for EE, Sendust Powder Cores .........................................................3-48 47. Manufacturers’ Material Product List ...............................................................................................3-49 48. References ..............................................................................................................................................3-50 Downloaded By: 10.3.98.104 At: 07:25 27 Sep 2021; For: 9781439836880, chapter3, 10.1201/b10865-4 © 2011 by Taylor and Francis Group, LLC 3-4 Magnetic Cores Introduction The key ingredient in a magnetic device is the magnetic field (flux) created when current is passed through a coiled wire. The ability to control (channel, predict, conduct), the magnetic field (flux) is critical to control- ling the operation of the magnetic device. The ability of a material to conduct magnetic flux is defined as permeability. A vacuum is defined as having a permeability of 1.0 and the permeability of all other materials is measured against this baseline. Most mate- rials, such as air, paper, and wood are poor conductors of magnetic flux, in that they have low permeability. If wire is wound on a dowel, it exhibits an exact magnetic field, as shown in Figure 3-1. There are a few materi- als, such as iron, nickel, cobalt, and their alloys that have high permeabilities, sometimes ranging into the hundreds of thousands. These materials and their alloys are used as the base materials for all core materials. Magnetic Flux, Φ Current, I Coil Dowel Figure 3-1. Air Core with an Intensified Magnetic Field. The main purpose of the core is to contain the magnetic flux and create a well-defined, predictable path for the flux. This flux path, and the mean distance covered by the