 The Significance of the Air/Epoxy Gap in a E-E Ferrite Core.
|
|
|
Patrick
|
|
Wed Jan 02 2019, 07:44PM
|
|
|
Registered Member #2431
Joined: Tue Oct 13 2009, 09:47PM
Location: Chico, CA. USA
Posts: 5639
|
Trying to minimize the gap is a goal in putting together my EE ferrite cores. TV flybacks store energy in their gap, which is deliberate.
is this relationship of distance non-linear? meaning a .001-.003 isnt too bad ? I obviously dont want huge kickbacks swinging around my low voltage PS's.
|
|
Back to top
|
|
|
hen918
|
|
Registered Member #11591
Joined: Wed Mar 20 2013, 08:20PM
Location: UK
Posts: 556
|
Usually when putting E cores together without a gap, the cores are pushed together, and epoxied afterwards. Then the gap is basically nothing, and it's easier to take apart if you have to.
There is a non-linear relationship; as the permeability of free space is much less (by three orders of magnitude) than that of the core, when the gap is < 1/1000 the length of the magnetic circuit, the reluctance of the gap is comparable to the reluctance of the core. The datasheet of the core will give you the length of the magnetic circuit (le) and the relative permeability (µe). If the gap is < le/(µe*10) its effects are negligible.
|
|
Back to top
|
|
Moderator(s): Chris Russell, Noelle, Alex, Tesladownunder, Dave Marshall, Dave Billington, Bjørn, Steve Conner, Wolfram, Kizmo, Mads Barnkob
|
|
Powered by e107 Forum System
|
