How do find Ae is the effective cross sectional area of a binocular core - Page 1
Forum section: electronics / projects

author: Qmavam
author_rank: Regular Contributor
timestamp: December 17, 2024, 03:47:56 am
content: I want the Ae of a 73-202 core AKA BN-2873000202.Ae is effective cross sectional area. (Side note, I don't know if it is different from just the cross sectional area)The cores I have measure as in the image.Thanks for your help, Mikek

author: moffy
author_rank: Super Contributor
timestamp: December 17, 2024, 05:28:10 am
content: Ae = B*(C - H)/2 mm2 but there is something wrong with the dimensions, the tolerances in some cases are larger than the actual dimension e.g. A= 0.527mm with tol.= +/-0.60mm

author: PGPG
author_rank: Frequent Contributor
timestamp: December 17, 2024, 12:50:32 pm
content: Quote from: Qmavam on December 17, 2024, 03:47:56 amAe is the same as cross sectional area if cross sectional area is constant along the magnetic path in core (true probably only for torroid cores).If cross section changes along the magnetic path I think the Ae is little higher than minimum of cross section along the way.Quote from: moffy on December 17, 2024, 05:28:10 amI'm not 'ferryte core specialist' but I think that this value is correct for turns using only one hole. For turns going back through second hole Ae can be assumed being twice of this, but not higher than ferryte core cross section between holes (what can give very close (but may be little higher) result to this equation).

author: Qmavam
author_rank: Regular Contributor
timestamp: December 17, 2024, 02:11:59 pm
content: Quote from: moffy on December 17, 2024, 05:28:10 amYou can ignore tolerence, I actually measured the core and inserted it into the boxes. I could not find a manufacture's data sheet that matched.That tolerance of 0.6mm is mostly likely a mistype.

author: Qmavam
author_rank: Regular Contributor
timestamp: December 17, 2024, 03:43:22 pm
content: Quote from: PGPG on December 17, 2024, 12:50:32 pmI can't proceed until I know if I need to double this or not, anyone have addition input, a manufacturer's reference would be great, but I have not found one.Thanks, Mikek

author: Qmavam
author_rank: Regular Contributor
timestamp: December 17, 2024, 03:49:48 pm
content: [quote author=moffy link=topic=447975.msg5750449#msg5750449 there is something wrong with the dimensions, the tolerances in some cases are larger than the actual dimension e.g. A= 0.527mm with tol.= +/-0.60mmOh goodness, I measured with my micrometer set to inches not mm.The tolerances make sense!

author: Qmavam
author_rank: Regular Contributor
timestamp: December 17, 2024, 03:58:10 pm
content: Quote from: moffy on December 17, 2024, 05:28:10 amAre these parenthesis correct for the formula? Ae = (B*(C-H)) / 2 in mm2

author: PGPG
author_rank: Frequent Contributor
timestamp: December 17, 2024, 04:54:54 pm
content: Quote from: Qmavam on December 17, 2024, 03:58:10 pmAccording to math I was taught: B*(C-H)/2 = (B*(C-H)) / 2Quote from: Qmavam on December 17, 2024, 03:43:22 pmMore important was what I have written just after comma: "but not higher than ferryte core cross section between holes" ( =B*(E-H) ).

author: Qmavam
author_rank: Regular Contributor
timestamp: December 17, 2024, 05:23:20 pm
content: Quote from: PGPG on December 17, 2024, 04:54:54 pmI think just went beyond my ability. I'll try to get the answer from the manufacturer. I can't find it online It is a Fair-Rite 202 binocular core.I'm working with the formula B= (Vrms x 10^8) / (4.44 * f * Np *Ae)B=Magnetic Flux Density f = frequency in Hz, Np is number of turns.So, I'm trying to find Ae.Thanks on the math syntax answer.Mikek