Re: Solid state TC progress ?

To: tesla-at-PUPMAN-dot-com
Subject: Re: Solid state TC progress ?
From: "Harri Suomalainen" <harri.suomalainen-at-pp.inet.fi> (by way of Terry Fritz <twftesla-at-uswest-dot-net>)
Date: Mon, 03 May 1999 16:09:27 -0600
Approved: twftesla-at-uswest-dot-net
Delivered-To: fixup-tesla-at-pupman-dot-com-at-fixme

>Original Poster: Alan Sharp <AlanSharp-at-compuserve-dot-com> 
>How do I calculate the leakage induction?

Some info could be found from many of the books about ferrites. I recommend
Soft Ferrites (written by by Snelling) which is a very thorough book on the
subject.

Beware the facts that inductance changes due to different operating points and
different temperatures. Leakage inductance is never easy to get accurately.
Fortunately you do not need it very accurately. You can also add some external
inductance to tune it.

>Is there a voltage rise accross
>the primary?

In series loaded topology no. In parallel loaded topology yes (ie. load in
parallel
with the cap). Then there is also the series-parallel combination which is more
or less between the former two. Then there are quite a few of some clamped
topologies.

The choise of topology depends on many things. I'd pick a parallel loaded
topology
with the cap on part of the secundary side as a first choise. Leakage
inductance
would not be a problem then. Transformer capasitance would be used as a circuit
"component" too. Voltage rise at no load is the main consern in this topology.

>What controller chip are you using?

There are many good resonant controllers in UC386x series. Most just seem to
be hard-to-find parts over here. I selected UC3825 for hand-tuned operation.