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Subject: Re: Boosting output from 120V inverter
References: <0001HW.B9DF7C5F00256614162B2870@news.covad.net> <firstname.lastname@example.org>
Date: Sat, 26 Oct 2002 23:13:37 GMT
NNTP-Posting-Date: Sat, 26 Oct 2002 19:13:37 EDT
Fan cooling will not much reduce internal hot spot. Hot spot is what hurts the winding. Oil cooling will
do. Power companies do it on their massive transformer. They've got oil pump too.
"N. Thornton" wrote:
> "Bevan Weiss" wrote in message news:<email@example.com>...
> > It's not that simple unfortuneately...
> > The transformer itself probably wont be rated that much above what the
> > entire inverter is rated at. So just replacing the MOSFET's wouldn't do the
> > trick, you'd have to replace the transformer as well, and the transformer is
> > almost the entire cost of an inverter, apart from design.
> > "DaveC" wrote in message
> > news:0001HW.B9DF7C5F00256614162B2870@news.covad.net...
> > > 200W inverter needs to run a bit more power. I know how cheap these things
> > > are, but I get my kicks from using and/or modifying what I have and
> > getting
> > > the experience of electronics theory/application.
> > >
> > > How should I go about matching up a higher-amperage MOSFET to replace the
> > > ones there? Same g-d and g-s voltages? Higher d current? Pin
> > configuration,
> > > of course. What are the critical specs I should focus on when looking for
> > an
> > > upgrade?
> > >
> > > The MOSFETS that switch the output are not heatsinked very well, and there
> > is
> > > room for a small cooling fan.
> > > --
> > > Note that my return address is corrupted in an attempt to reduce spam. If
> > you
> > > choose to e-mail me, please correct my address as described below.
> > >
> > > Thanks,
> > > Dave
> I think it could work actually, with a fan. Transformers will handle
> much more power when fan cooled. So I'd put as powerful a fan in there
> as you can squeeze, uprate your fets, and watch the TF temp to see
> what it'll manage continuous. Hopefully you'll get a significant
> Since youre running off battery, you'll want to power the fan
> If you're real determined, theres always the outer edge option of
> putting the TF in a well heatsunk tin full of oil - no fan power then.
> Regards, NT