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thermal_resistance_of_ferrite_cores [2019/06/03 18:30]
thermal_resistance_of_ferrite_cores [2020/07/19 01:53] (current)
stan_zurek
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 +====== Thermal resistance of ferrite cores ======
 +
 +|< 100% >|
 +| //[[user/Stan Zurek]], Thermal resistance of ferrite cores, [[http://Encyclopedia-Magnetica.com|Encyclopedia-Magnetica.com]], {accessed @YEAR@-@MONTH@-@DAY@}// |
 +
 +|< 100% >|
 +| {{/wiki/logo.png?20&nolink}} //See also the main article: [[Thermal resistance]].// |
 +
 +
 +The values of [[thermal resistance]] of main core shapes for [[ferrite transformer|ferrite transformers]], cooled by natural convection in air (no forced cooling) are given in the tables below.[(Epcos>[[http://www.epcos.com/web/generator/Web/Sections/ProductCatalog/Ferrites/RMCores/PDF/PDF__Application,property=Data__en.pdf;/PDF_Application.pdf|Epcos, Ferrites and accessories, Application notes, September 2006, p. 23-29, {accessed 9 Nov 2012}]])][(Fundamentals>[[http://books.google.com/books?isbn=0792372700|Robert W. Erickson, Dragan Maksimović, Fundamentals of power electronics, 2nd edition, Springer, Colorado, 2001, ISBN 0-7923-7270-0]])]
 +[(Goldman>[[http://books.google.com/books?isbn=0412146614|Alex Goldman, Handbook of modern ferromagnetic materials, Kluwer Academic Publishers, 2002, ISBN 0412146614, p. 500]])]
 +
 +Empirical data given by [[Epcos]] (see image) suggest that in the first approximation the thermal resistance is proportional to the reciprocal of square root of the ferrite core volume.[(Epcos)][(Maniktala>[[http://books.google.com/books?isbn=9780123865335|Sanjaya Maniktala, Switching power supplies A-Z, 2nd edition, Newnes, 2012, ISBN 978-0-12-386533-5, p. 155]])]
 +
 +{{page>insert/paypal}}
 +
 +<box left 70% #f0f0f0>
 +Thermal resistance of ferrite cores, the dashed line shows the underlying trend proportional to the reciprocal of square root of core volume[(Epcos)]
 +[[file/thermal_resistance_of_ferrite_cores.png|{{thermal_resistance_of_ferrite_cores.png}}]]
 +{{page>insert/by_SZ}}
 +</box>
 +
 +<WRAP clear></WRAP>
 +{{page>calculator/thermal_resistance_of_ferrite_cores}}
 +
 +===== E (EE) =====
 +^ Core shape [[E (core)|E]]  ^ //R<sub>th</sub>// (K/W)[(Epcos)]  ^  //R<sub>th</sub>// (K/W)[(Goldman)] ^ //R<sub>th</sub>// (K/W) \\ //calculated from equation//[(Maniktala)] ^
 +| E 5.3/2.7/2 | 308 |    | 334 |
 +| E 6.3/2.9/2 | 283 |    | 290 |
 +| E 8.8/4.1/2 | 204 |    | 210 |
 +| E 13/7/   | 94  |    | 91  |
 +| E 14/8/   | 79  |    | 75 |
 +| E 16/6/   | 76  |    | 73 |
 +| E 16/8/   | 65  |    | 62 |
 +| E 19/8/   | 60  |    | 56 |
 +| E 20/10/  | 46  | 50 | 43 |  
 +| E 21/9/   | 59  |    | 55 |
 +| E 25/13/  | 40  | 40 | 29 |
 +| E 25.4/10/7 | 41  |    | 37 |
 +| E 30/15/  | 23  | 23 | 25 |
 +| E 32/16/  | 22  | 22 | 20 |
 +| E 32/16/11  | 21  | 22 | 18 |
 +| E 34/14/  | 23  |    | 20 |
 +| E 36/18/11  | 18  |    | 16 |
 +| E 40/16/12  | 20  | 20 | 14 |
 +| E 42/21/15  | 19  | 19 | 11 |
 +| E 42/21/20  | 15  | 15 | 10 |
 +| E 47/20/16  | 13  | 13 | 10 |
 +| E 55/28/21  | 11  | 11 | 7  |
 +| E 55/28/25  | 8   | 8  | 6.9 |
 +| E 56/24/19  | 9.5 |    | 7.7 |
 +| E 65/32/27  | 6.5 | 6  | 5.0 |
 +| E 70/33/32 (E71/33/32)  | 5.5 |    | 4.4 |
 +| E 80/38/20  | 7      | 5.3 |
 +
 +===== EC =====
 +^ Core shape [[EC (core)|EC]] ^ //R<sub>th</sub>// (K/W)[(Fundamentals)] ^  //R<sub>th</sub>// (K/W)[(Goldman)] ^ //R<sub>th</sub>// (K/W) \\ //calculated from equation//[(Maniktala)] ^
 +| EC 35 | 18.5 | 18 | 19 |
 +| EC 41 | 16.5 | 15 | 15 |
 +| EC 52 | 11.0 | 11 | 11 |
 +| EC 70 | 7.5 | 7 | 7.2 |
 +
 +===== EE LP =====
 +^ Core shape [[EE LP (core)|EE LP]] ^ //R<sub>th</sub>// (K/W)[(Epcos)] ^ //R<sub>th</sub>// (K/W) \\ //calculated from equation//[(Maniktala)] ^
 +| EE LP 14  | 105 | 102 |
 +| EE LP 18  | 56 | 54.3 |
 +| EE LP 22  | 35 | 32.0 |
 +| EE LP 32  | 24 | 21.3 |
 +| EE LP 38  | 18 | 15.1 |
 +| EE LP 43  | 15 | 12.9 |
 +| EE LP 58  | 11 | 9.3 |
 +| EE LP 64  | 9  | 7.1 |
 +
 +
 +===== EFD =====
 +
 +<box right 30% #f0f0f0>
 +Transformer [[EFD25]]
 +[[file/EFD25 transformer Magnetica.jpg|{{EFD25 transformer Magnetica.jpg}}]]
 +{{page>insert/by_SZ}}
 +</box>
 +
 +^ Core shape [[EFD (core)|EFD]]  ^ //R<sub>th</sub>// (K/W)[(Epcos)][(Goldman)] ^ //R<sub>th</sub>// (K/W) \\ //calculated from equation//[(Maniktala)] ^
 +| EFD 10/5/ | 120 | 138 |
 +| EFD 15/8/ | 75  | 76 |
 +| EFD 20/10/7 | 45  | 43 |
 +| EFD 25/13/9 | 30  | 28 | 
 +| EFD 30/15/9 | 25  | 23 | 
 +
 +===== EI LP =====
 +^ Core shape [[EI LP (core)|EI LP]]  ^ //R<sub>th</sub>// (K/W)[(Epcos)] ^ //R<sub>th</sub>// (K/W) \\ //calculated from equation//[(Maniktala)] ^
 +| EI LP 14  | 116 | 114 |
 +| EI LP 18  | 61 | 59.7 |
 +| EI LP 22  | 38 | 36.0 |
 +| EI LP 32  | 26 | 23.4 |
 +| EI LP 38  | 20 | 16.7 |
 +| EI LP 43  | 16 | 14.2 |
 +| EI LP 58  | 12 | 10.2 |
 +| EI LP 64 | 9.5 | 7.6 |
 +
 +===== EP =====
 +^ Core shape [[EP (core)|EP]] ^ //R<sub>th</sub>// (K/W)[(Epcos)] ^ //R<sub>th</sub>// (K/W) \\ //calculated from equation//[(Maniktala)] ^ 
 +| EP 5  | 329 | 352* |  
 +| EP 6  | 318 | 346* |
 +| EP 7  | 141 | 142* |
 +| EP 10 | 122 | 121* |
 +| EP 13 | 82 | 79* |
 +| EP 17 | 58 | 54* |
 +| EP 20 | 32 | 29* |
 +| // *The calculated values are given here for comparison only, as the results can differ significantly for the non-E-like cores. // ||| 
 +
 +===== ER =====
 +^ Core shape [[ER (core)|ER]]  ^ //R<sub>th</sub>// (K/W)[(Epcos)] ^ //R<sub>th</sub>// (K/W)[(Goldman)] ^ //R<sub>th</sub>// (K/W) \\ //calculated from equation//[(Maniktala)] ^
 +| ER 9.5/2.5/           | 164 |    | 166 |
 +| ER 11/2.5/6 (ER 11/5)   | 134 |    | 136 |
 +| ER 14.5/3/7 (ER 14.5/6) | 99  |    | 96 |
 +| ER 28/14/11 |    |    | 22 |
 +| ER 28/17/11 | 22 |    | 20 |
 +| ER 35/20/11 | 18 |    | 15 |
 +| ER 42/22/15 | 14 | 12 | 12 |
 +| ER 46/17/18 | 13 |    | 12 |
 +| ER 49/27/17 | 9  | 9  | 8.7  |
 +| ER 54/18/18 | 11 | 11 | 9.7  |
 +
 +===== ETD =====
 +
 +<box right 30% #f0f0f0>
 +Transformer [[ETD44]]
 +[[file/transformer_etd44_160w_magnetica.jpg |{{transformer_etd44_160w_magnetica.jpg }}]]
 +{{page>insert/by_SZ}}
 +</box>
 +
 +^ Core shape [[ETD (core)|ETD]]  ^ //R<sub>th</sub>// (K/W)[(Epcos)][(Goldman)] ^ //R<sub>th</sub>// (K/W)[(Fundamentals)] ^ //R<sub>th</sub>// (K/W) \\ //calculated from equation//[(Maniktala)] ^
 +| ETD 19/14/ |    |    | 32.7 |
 +| ETD 24/15/ |    |    | 26.2 |
 +| ETD 29/16/10 | 28 |    | 21.2 | 
 +| ETD 34/17/11 | 20 | 19 | 17.7 |
 +| ETD 39/20/13 | 16 | 15 | 14.2 |
 +| ETD 44/22/15 | 11 | 12 | 11.2 |
 +| ETD 49/25/16 | 8  | 11 | 9.5 |
 +| ETD 54/28/19 | 6  |    | 7.7 |
 +| ETD 59/31/22 | 4  |    | 6.3 | 
 +
 +
 +===== EV =====
 +^ Core shape [[EV (core)|EV]]  ^ //R<sub>th</sub>// (K/W)[(Epcos)] ^ //R<sub>th</sub>// (K/W) \\ //calculated from equation//[(Maniktala)] ^ 
 +| EV 15/9/  | 55 | 51 |
 +| EV 25/13/13 | 27 | 24 |
 +| EV 30/16/13 | 21 | 18 |
 +
 +
 +===== P =====
 +^ Core shape [[P (core)|P]] ^ //R<sub>th</sub>// (K/W)[(Epcos)]  ^ //R<sub>th</sub>// (K/W)[(Goldman)] ^ //R<sub>th</sub>// (K/W) \\ //calculated from equation//[(Maniktala)] ^  
 +| P 3.2/2.6 |       | 773* |
 +| P 4.6/4.1 |       | 424 *|
 +| P 5.8/3.3 |       | 314* |
 +| P 7/4           | 223* |
 +| P 9/5   | 142 |     | 143* |
 +| P 11/7  | 106 |     | 104* |
 +| P 14/8  | 73  | 100 | 70* |
 +| P 18/11 | 51  | 60 | 47* |
 +| P 22/13 | 37  | 38 | 33* |
 +| P 26/16 | 27  | 30 | 24* |
 +| P 30/19 | 22  | 23 | 19* |
 +| P 36/22 | 17  | 19 | 14* |
 +| P 41/25 |    |     | 12* |
 +| P 42/29 |   | 13.5 | 11* |
 +| P 66/56 |    |     | 4.7* |
 +| // *The calculated values are given here for comparison only, as the results can differ significantly for the non-E-like cores. // |||| 
 +
 +
 +===== PM =====
 +^ Core shape [[PM (core)|PM]]  ^ //R<sub>th</sub>// (K/W)[(Epcos)] [(Goldman)] ^ //R<sub>th</sub>// (K/W) \\ //calculated from equation//[(Maniktala)] ^
 +| PM 50/39  | 15 | 8.3* |
 +| PM 62/49  | 12 | 5.7* |
 +| PM 74/59  | 9.5 | 4.4* |
 +| PM 87/70  | 8 | 3.8* |
 +| PM 114/93 | 6 | 2.3* |
 +| // *The calculated values are given here for comparison only, as the results can differ significantly for the non-E-like cores. // ||| 
 +
 +
 +===== PQ =====
 +^ Core shape [[PQ (core)|PQ]] ^ //R<sub>th</sub>// (K/W) ^ //R<sub>th</sub>// (K/W) \\ //calculated from equation//[(Maniktala)] ^
 +| PQ 16/11.6 | | 49* |
 +| PQ 20/16  | | 33* |
 +| PQ 20/20  | | 30* |  
 +| PQ 26/20 | 24 [([[http://www.onsemi.com/pub_link/Collateral/TND350-D.PDF|Magnetics in Switched-Mode Power Supplies, ON Semiconductor, p. 51, {accessed 10 Jul 2013}]])] | 21* |
 +| PQ 26/25  | | 19* |
 +| PQ 32/20  | | 18* | 
 +| PQ 32/30  | | 15* |
 +| PQ 35/35  | | 13* |
 +| PQ 40/40  | | 10* |
 +| // *The calculated values are given here for comparison only, as the results can differ significantly for the non-E-like cores. // ||| 
 +
 +
 +===== RM =====
 +
 +<box right 30% #f0f0f0>
 +Transformer [[RM8]]
 +[[file/RM8_core_3H1_A250_Magnetica.jpg|{{RM8_core_3H1_A250_Magnetica.jpg}}]]
 +{{page>insert/by_SZ}}
 +</box>
 +
 +^ Core shape [[RM (core)|RM]] ^ //R<sub>th</sub>// (K/W)[(Epcos)] [(Goldman)] ^ //R<sub>th</sub>// (K/W) \\ //calculated from equation//[(Maniktala)] ^
 +| RM 4  | 120 | 98* | 
 +| RM 5  | 100 | 72* |
 +| RM 6  | 80 | 52* |
 +| RM 7  | 68 | 46* |
 +| RM 8  | 57 | 33* |
 +| RM 10 | 40 | 24* |
 +| RM 12 | 25 | 17* |
 +| RM 14 | 18 | 13* |
 +| // *The calculated values are given here for comparison only, as the results can differ significantly for the non-E-like cores. // ||| 
 +
 +===== RM LP =====
 +^ Core shape [[RM LP (core)|RM LP]]  ^ //R<sub>th</sub>// (K/W)[(Epcos)] ^ //R<sub>th</sub>// (K/W) \\ //calculated from equation//[(Maniktala)] ^
 +| RM 4 LP | 135 | 112* |
 +| RM 5 LP | 111 | 84* |
 +| RM 6 LP | 90 | 59* |
 +| RM 7 LP | 78 | 51* |
 +| RM 8 LP | 65 | 38* |
 +| RM 10 LP | 45 | 28* |
 +| RM 12 LP | 29 | 20* |
 +| RM 14 LP | 21 | 15* |
 +| // *The calculated values are given here for comparison only, as the results can differ significantly for the non-E-like cores. // ||| 
 +
 +
 +===== UI =====
 +^ Core shape [[UI (core)|UI]] ^ //R<sub>th</sub>// (K/W)[(Epcos)] ^ //R<sub>th</sub>// (K/W) \\ //calculated from equation//[(Maniktala)] ^ 
 +| UI 93/104/16  | 5 | 4.1* |
 +| UI 93/104/20  | 4.5 | 3.6* |
 +| UI 93/104/30  | 4 | 2.9* |
 +| // *The calculated values are given here for comparison only, as the results can differ significantly for the non-E-like cores. // ||| 
 +
 +
 +===== UU and U =====
 +^ Core shape [[UU (core)|UU]] ^ //R<sub>th</sub>// (K/W)[(Epcos)] ^ //R<sub>th</sub>// (K/W)[(Goldman)] ^ //R<sub>th</sub>// (K/W) \\ //calculated from equation//[(Maniktala)] ^ 
 +| U 11  |  | 46 | 
 +| U 15  |  | 35 |
 +| U 17  |  | 30 |
 +| U 20  |  | 24 |
 +| U 21  |  | 22 |  
 +| U 25  |  | 15 | 
 +| U 26  |  | 13 |
 +| U 30  |  | 4 |
 +| UU 93/152/16 | 4.5 | | 
 +| UU 93/152/20 | 4 | 1.7 |
 +| UU 93/152/30 | 3 | 1.2 | 
 +| U 101/76/30  | 3.3 | | 2.4* |
 +| U 126/91/20  |     | | 2.6* |
 +| U 141/78/30  | 2.5 | | 1.8* |
 +| // *The calculated values are given here for comparison only, as the results can differ significantly for the non-E-like cores. // ||||
 +
 +===== See also=====
 +  * [[Thermal resistance]]
 +  * [[List of ferrite core types]]
 +
 +~~REFNOTES~~
 +
 +{{tag>Thermal_resistance Calculators Counter}}
  

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