From: Philip A. Marshall
Subject: Re: Boosting output from 120V inverter
References: <0001HW.B9DF7C5F00256614162B2870@news.covad.net> <firstname.lastname@example.org>
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Date: Sat, 26 Oct 2002 23:54:13 GMT
NNTP-Posting-Date: Sat, 26 Oct 2002 17:54:13 MDT
On 26 Oct 2002 10:41:45 -0700, email@example.com (N. Thornton) wrote:
>"Bevan Weiss" wrote in message news:<firstname.lastname@example.org>...
>> 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
>> > 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
>> > 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
>> > of course. What are the critical specs I should focus on when looking for
>> > upgrade?
>> > The MOSFETS that switch the output are not heatsinked very well, and there
>> > room for a small cooling fan.
>> > --
>> > Note that my return address is corrupted in an attempt to reduce spam. If
>> > 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.
as long as you cool the oil somehow. otherwise it will just heat up
slowly and then stay just very hot for a long time. as you say,
passive cooling may work, just so long as you watch the temperature of
the oil to make sure it stabalizes at a reasonable temperature.