Re: MOT core

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Richard W." <potluckutk-at-comcast-dot-net> 

Actually decreasing the core cross-section by half will drop the power
capability almost by a factor of 4.

Let's say we have a core who's center leg measures 1" x 2" for 2 square
inches.

CS = 2 sq.in. (Cross Section)

VA = (CS/0.16)^2
VA = (2/0.16)^2
VA = 12.5^2
VA = 156

Cutting the core in half = 1 sq.in.

VA = (CS/0.16)^2
VA = (1/0.16)^2
VA = 6.25^2
VA = 39

Rick W
Salt Lake City

----- Original Message -----
From: Tesla list <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Sunday, February 01, 2004 7:34 PM
Subject: Re: MOT core


 > Original poster: "Hydrogen18" <hydrogen18-at-hydrogen18-dot-com>
 >
 > The only thing I know to say here is stack the cores. Alternatively you
 > could use very small wire for the secondary to achieve the HV output.
 > Stacking the cores(inserting 1 E into each end of the "bobbins") will
halve
 > your power output but double your winding window.
 > ----- Original Message -----
 > From: "Tesla list" <tesla-at-pupman-dot-com>
 > To: <tesla-at-pupman-dot-com>
 > Sent: Sunday, February 01, 2004 6:49 PM
 > Subject: MOT core
 >
 >
 >  > Original poster: "Dan" <pbursa-at-cfl.rr-dot-com>
 >  >
 >  > Hello !
 >  > I am curious if someone here has experience with rewinding microwave
 >  > transformer.
 >  > I cut of the I part of the core, removed old windings and split the E
core
 >  > in half so now I have two identical E cores .
 >  > Together they make 5.5 inches long, 4.15 wide and 1.35 thick core with
 >  > about 1.72 square inches area...
 >  > This looks like I'll need over 400 turns on primary... this would
require
 >  > 40000 turns for 12KV secondary and there is not enough space for this,
I'm
 >  > afraid.
 >  > My question is - if I use less primary windings (say 150 - 200), how it
 >  > affect performance, core saturation, ...
 >  > I noticed that original MOTs primary was also less than proper amount
of
 > turns.
 >  > Also, since MOT core is welded together, how the weld affect the core
 >  > losses and eddy currents? isn't the very purpose of using laminated
core
 > to
 >  > minimize these loses ?
 >  > How about potting finished transformer in oil ?
 >  > Thank you in advance
 >  > Vladan
 >  >
 >  >
 >  >
 >
 >