Re: CCFL transformer

On 28/04/2024 3:17 am, legg wrote:

On Sat, 27 Apr 2024 01:26:09 +1000, Bill Sloman <bill.sloman@ieee.org wrote:

On 27/04/2024 12:24 am, legg wrote:

On Fri, 26 Apr 2024 01:36:06 +1000, Bill Sloman <bill.sloman@ieee.org>wrote:

On 26/04/2024 12:52 am, legg wrote:

On Wed, 24 Apr 2024 01:57:36 +0200, Klaus Vestergaard Kragelund <klauskvik@hotmail.com> wrote:

There's a least one truly horrible 1969 text book on transformer design
>
https://www.amazon.com.au/Soft-Ferrites-Applications-C-Snelling/dp/0408027606
>
and it took me years to realise quite how confusing it was.

>
In my day, it was considered to be the bible, but I could never
afford a copy, so depended on photocopies and library access.

>
I worked for EMI Central Research at time I thought that I needed it, so
access wasn't a problem. The Seimens soft ferrite application notes
turned out to be a great deal more useful, and much better organised.

 I believe it was Janson, Barrow and Burgum, with Jongsma at Philips
(Mullard), who reorganized Snelling's math into useful off-the-cuff
expressions in the mid 70s. . . using the Steinmetz coefficients etc.
 E.A.B. 32 through 34 are typical, if my records are accurate.

Never got to see any of that.

 The Seimens catalog notes for use of power ferrite graphs 'sort of'
did the same, without actually explicitly stating ANY of them.
They were free and in book form.
 Anyways, high voltage applications are a different book.

Why? The ferrites never get to see the high voltages.
The windings do. When I was a graduate student I got to know a guy - Ales Strojnik - who had come from Slovenia to Melbourne to build a 600kV scanning transmission microscope,and immersed his winding in liquid transformer oil. Sulphur hexafluoride gas was more popular but made for a bulkier system.
https://en.wikipedia.org/wiki/Ale%C5%A1_Strojnik
He was rude about the French higher voltage version, which was huge.
--
Bill Sloman, Sydney