Re: Big Ferrite Transformer (fwd)

[Steven Roys <sroys@xxxxxxxx>]

---------- Forwarded message ----------
Date: Thu, 8 Apr 2004 20:41:32 +0200
From: gtyler <gtyler@xxxxxxxxxxxxxxx>
To: High Voltage list <hvlist@xxxxxxxxxx>
Subject: Re: Big Ferrite Transformer (fwd)

Looks like a standard U93 core to me. Asking "what power can it handle"
is a bit like "how long is a piece of string". It depends on the
topology of the electronics driving it as well as the Frequency. I have
made A 140Kv Xray transformer out of a set like that that ran at about
1Kw, but the winding was mainly insulation. It did not work to well due
to internal resonances.

Regards George

----- Original Message -----
From: "High Voltage list" <hvlist@xxxxxxxxxx>
To: <hvlist@xxxxxxxxxx>
Sent: Monday, April 05, 2004 6:58 AM
Subject: Big Ferrite Transformer (fwd)


> Original poster: Steven Roys <sroys@xxxxxxxx>
>
>
>
> ---------- Forwarded message ----------
> Date: Mon, 05 Apr 2004 11:51:33 +0930
> From: Matthew Smith <matt@xxxxxxxxxx>
> To: High Voltage list <hvlist@xxxxxxxxxx>
> Subject: Big Ferrite Transformer
>
> Hi All
>
> <http://www.mss.cx/ferrite.jpg> shows a large ferrite transformer that
I
> acquired some time ago.  It was described as an "avionics
transformer", although
> I thought that aircraft ran on 400Hz with iron cores.  This is a big
lump of
> ferrite.  (See AA battery for scale.)
>
> The whole thing weighs 1.5kg and the low-voltage winding is a pair of
3mm^2
> conductors (bifiliar).  Turns ratio is 1:56, established by a rough
calculation
> of SQRT(L1/L2).   The HV winding is actually split into two spools.
>
> Would anyone like to hazard a guess as to the power handling of a
transformer
> like this, assuming that I drive it at 40kHz?  (I'd like to go higher,
but don't
> want to be putting all my energy into making the ferrite hot ;-)
>
> There seems to be a good few turns of paper between primary and
secondary and,
> considering the dual-spool HV side, would guess that it could take a
reasonably
> high voltage.  Should I just drop it in a tub of oil to be safe?
>
> There's a temptation to run it off-line (340V from bridge-rectified
240V) but,
> as my physics teacher was wont to say, I think that it would have a
"short, gay,
> merry life".
>
> Thankfully, the core is held together with iron bands (not glue), so
can be
> disassembled and rewound if necessary.
>
> Cheers
>
> M
>
> --
> Matthew Smith
> Kadina Business Consultancy
> South Australia
> http://www.kbc.net.au
>
>
>