### Author Topic: Effective dimensions of binocular ferrite core  (Read 745 times)

0 Members and 1 Guest are viewing this topic.

#### Telegraph

• Newbie
• Posts: 3
• Country:
##### Effective dimensions of binocular ferrite core
« on: January 04, 2021, 07:26:15 pm »
I was trying to do calculations on a ferrite binocular core.  I found formulas to calculate the permeability that require the effective area and magnetic path length.  For a regular toroid, or bead, that appears to be straight forward.  What about a binocular (mulit-aperture core)?  I found documentation for more complex arrangements, such as, E-cores but nothing on the binocular format.

#### richard.cs

• Super Contributor
• Posts: 1184
• Country:
• Electronics engineer from Southampton, UK.
##### Re: Effective dimensions of binocular ferrite core
« Reply #1 on: January 04, 2021, 11:01:49 pm »
Treat is as two independent tube cores, each like a long bead.

#### igor78

• Contributor
• Posts: 21
• Country:
##### Re: Effective dimensions of binocular ferrite core
« Reply #2 on: March 28, 2023, 06:23:31 am »
This topic comes first in websearch. For future readers:

Page 2 here
https://www.tdk-electronics.tdk.com/inf/80/db/fer/double_aperture_cores.pdf

Notice the dimension units there mm^-1

Also see https://owenduffy.net/blog/?p=14712 "Geometry factors for some common Fair-rite binocular ferrite cores"

 Core BN designation ΣA/l (m) 2843000202 BNxx-202 0.00288 2843000302 BNxx-302 0.00211 2843001502 BNxx-1502 0.00139 2843002402 BNxx-2402 0.00154 2843010402 0.00308
« Last Edit: March 28, 2023, 07:09:41 am by igor78 »

#### jonpaul

• Super Contributor
• Posts: 2824
• Country:
##### Re: Effective dimensions of binocular ferrite core
« Reply #3 on: March 30, 2023, 01:48:13 pm »
for,a shield EMI bead, see mfg specs,
for use,as balun, the exact spec is seldom important

We just wind and test on a high frequency RLC or impedance analyzer
j

Jean-Paul (EE 1968, the Internet Dinosaur)

#### jonpaul

• Super Contributor
• Posts: 2824
• Country:
##### Re: Effective dimensions of binocular ferrite core
« Reply #4 on: March 30, 2023, 01:50:42 pm »
beside TDK try old Fair-Rite, EPCOS, Philips data.

j
Jean-Paul (EE 1968, the Internet Dinosaur)

Smf