Re: Mike Marcum Ferrite Cores >Terry look at this please<

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: Steve Ward <steve.ward@xxxxxxxxx>

I have similar cores to Mike's.  The max flux is about 3500 gauss, 
with a cross section of 1 square inch (6.45cm^2).   As Mike mentions, 
this changes with temp.  At 25*C you can run them at 4500gauss or so, 
but at 100*C you must derate to about 3500gauss.



No way! You mean for a 2" X 2" ferrite core the
max flux density is only 2k Gauss?!


2k is a low number (see above)... but ummm, who cares that its 
2x2?  Its flux *Density*, so the actual flux (in webers) depends on the area.

How can that
be so small? I've put some pretty big magnets on
even small core cross sections and had at least
half to two thirds of it come out the other side.


I dont understand your conclusion...

Is this decrease some frequency related issue??


No, but that does factor in when you consider power losses in the 
core.  Saturation is saturation, its dependent on the current, 
inductance, cross sectional area and number of turns... ive never 
seen frequency factored in (except for convenience, because current 
is dependent on voltage across the L for a given length of time).

B= (L*I*10^4)/(A*N).

---- Matt Cortner ----


I have also been working on a CCPS, inspired by Marco's project Thor 
power supply.  I have a webpage for it that really needs updating, 
but might be of interest to some of you:

<http://www.stevehv.4hv.org/ccps1.htm>http://www.stevehv.4hv.org/ccps1.htm

main site:

<http://www.stevehv.4hv.org>http://www.stevehv.4hv.org

Some additional pictures at my friends site (we have been working 
together on this power supply):

<http://www.twainhartetaylors.com/g2/main.php>http://www.twainhartetaylors.com/g2/main.php

Just go to the transformer albums, plenty of pics... though still out 
of date, haha.

Steve