Isolation transformers

Glenn Ashmore ha scritto:
> Can someone tell me the difference between the standard Charles 3.6kVA
> transformer and the ISO-G2 3.6kVA transformer? (Other than the $500
> difference in price, that is.)
>

I am not sure in this case but: look at the weight! There are on the
market isolation transformers that use a switching device: a relatively
complex electronic way to obtain the same average power by switching a
highest power on/off at high frequency. The classical high power
transformers are very heavy beacause they need a lot of copper wire and
metal and, at most, need a simple circuit to avoid the turn-on
overcurrent, the switching ones use much lighter (less heavy)
transformers but need active electronics to be driven.

Daniel
 >> Stay informed about: Isolation transformers 

In article <FtYoj.13967$M24.9654@newsfe17.lga>,
"Glenn Ashmore" <gashmore.TakeThisOut@cox.net> wrote:

> Can someone tell me the difference between the standard Charles 3.6kVA
> transformer and the ISO-G2 3.6kVA transformer? (Other than the $500
> difference in price, that is.)

If you look at the Spec Sheets for both transformers, I suspect you will
also note, that the more expensive one will have a Isolated,
non-Overlapping, Windings, and a Grounded Isolation Shield, between the
Primary, and Secondary Windings. This precludes any chance of a Fault
to the Core, causing the Isolation of the Transformer to be breached.

--
Bruce in alaska
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 >> Stay informed about: Isolation transformers 

On Feb 2, 7:47 am, Daniele Fua <daniele.....RemoveThis@unimib.it> wrote:
> There are on the
> market isolation transformers that use a switching device: a relatively
> complex electronic way to obtain the same average power by switching a
> highest power on/off at high frequency.

An isolation tranformer that is based on high frequency switching
electronics? Aren't isolation transformers basically 1:1 copper
windings on an iron core, potted in an epozy sand mix for thermal
mass?

Please point me to an example of an active electronics (lightweight)
marine isolation transformer.
 >> Stay informed about: Isolation transformers 

On Wed, 20 Feb 2008 13:04:52 -0800 (PST), Mark <axolotl73.TakeThisOut@hotmail.com>
wrote:

>On Feb 2, 7:47 am, Daniele Fua <daniele.....TakeThisOut@unimib.it> wrote:
>> There are on the
>> market isolation transformers that use a switching device: a relatively
>> complex electronic way to obtain the same average power by switching a
>> highest power on/off at high frequency.
>
>An isolation tranformer that is based on high frequency switching
>electronics? Aren't isolation transformers basically 1:1 copper
>windings on an iron core, potted in an epozy sand mix for thermal
>mass?
>
>Please point me to an example of an active electronics (lightweight)
>marine isolation transformer.

Here's one:

http://www.mastervolt.com/en/124/world's_first_switch-mode_isolation_transformer.html

It may not cost enough to qualify for "marine status" but just double
the price and it might work.

You can do a Yahoo search on switch mode isolation transformer and see
what else comes up.

Chuck

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 >> Stay informed about: Isolation transformers 

At 12 pounds and half the size of the Charles it looks good but at $1500 it
is a bit out of my price range. The other thing that I wonder about is the
specs say the output voltage is within 5% of the input voltage which means
there is no protection against low voltage. Even a regular switching power
supply supplies a stable voltage. A stable voltage is about the only reason
beyond weight and size I can think of for paying that much.

--
Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com

"Chuck" wrote.

>>Please point me to an example of an active electronics (lightweight)
>>marine isolation transformer.
>
> Here's one:
>
> http://www.mastervolt.com/en/124/world's_first_switch-mode_isolation_transformer.html
>
> It may not cost enough to qualify for "marine status" but just double
> the price and it might work.
 >> Stay informed about: Isolation transformers 

"Glenn Ashmore" <gashmore RemoveThis @cox.net> wrote in
news:6p6vj.3879$QC.2479@newsfe20.lga:

> At 12 pounds and half the size of the Charles it looks good but at
> $1500 it is a bit out of my price range. The other thing that I
> wonder about is the specs say the output voltage is within 5% of the
> input voltage which means there is no protection against low voltage.
> Even a regular switching power supply supplies a stable voltage. A
> stable voltage is about the only reason beyond weight and size I can
> think of for paying that much.
>
>

I was thinking about this thread during changing the oil in my trusty Honda
EU3000is electronic genset before dark.....

Wouldn't it be cool if someone were to build a diesel genset of the
technology of the electronic switching gensets like mine? When the boat is
off on its own, the slow-speed, economizing diesel's high voltage, high
frequency flywheel coils would power its precise 60 Hz, synthesized
switching AC power supply to drive the boat loads, as the diesel lumbers
along, not at 1800 or 3600 RPM, but a much slower speed only to provide the
electronics the DC to drive its output loads. When the boat is at the
dock, whatever AC voltage is available, anyplace on the planet, would be
rectified into DC and fed to the same ISOLATED electronic power supply that
would always provide an independent, isolated from shore grounds, AC power
voltage/frequency of your choice to drive you loads without fizzing your
zincs.

The technology to build the 6500 watt model already exists:
http://www.hayesequipment.com/eu6500is.htm
 >> Stay informed about: Isolation transformers 

Larry wrote:

<snip>
> Wouldn't it be cool if someone were to build a diesel genset of the
> technology of the electronic switching gensets like mine? When the boat is
> off on its own, the slow-speed, economizing diesel's high voltage, high
> frequency flywheel coils would power its precise 60 Hz, synthesized
> switching AC power supply to drive the boat loads, as the diesel lumbers
> along, not at 1800 or 3600 RPM, but a much slower speed only to provide the
> electronics the DC to drive its output loads.
<snip>

I did something similar in '91; drove a military 2 kVA alternator with an
oversized small engine. The alternator's output was full-wave rectified
and drove a Sola 2 kVA switching power supply (72 VDC in, 120 VAC 60 Hz out);
I also had a 72 volt 200 AH battery reservoir drive the supply when the
engine was off. It worked quite well. The engine could essentially run
at high idle to charge the batteries for my average load; the duty cycle
was about fifty percent.

Michael
 >> Stay informed about: Isolation transformers 

msg <msg.RemoveThis@_cybertheque.org_> wrote in
news:13rq6nf5r639fb5@corp.supernews.com:

> I did something similar in '91; drove a military 2 kVA alternator with
> an oversized small engine. The alternator's output was full-wave
> rectified and drove a Sola 2 kVA switching power supply (72 VDC in,
> 120 VAC 60 Hz out); I also had a 72 volt 200 AH battery reservoir
> drive the supply when the engine was off. It worked quite well. The
> engine could essentially run at high idle to charge the batteries for
> my average load; the duty cycle was about fifty percent.
>
> Michael
>
>

This idea would also work very well using the technology of the hybrid
cars, self-starting the engine only to recharge the high voltage, low
current battery pack much more efficient and certainly lighter than the old
lead-acid monsters that have little power storage. The boat would simply
have a constant supply of AC power to run everything, with several high
voltage charging systems, including the autostarting engine drive. As the
wind charger output increased, or the solar array, the engine would run
less and less. A computer controlling it all taking the power management
load we have now away from the inhabitants.

Of course, many would resist who want their boats to be time machines back
into the 1800's....(c;

If we get rid of the drive engine and go to high voltage traction motors to
power the shaft, we'll only need one engine to power both the screw and the
rest of the boat. It won't matter where the designers put this engine and
the inherent problem of always having to put the engine in the way in the
middle of the boat would disappear. A 50hp traction motor is quite small,
indeed. I think the boats would have more room without the old inline
diesel drives we have now.

Just dreaming. Change comes slow.
 >> Stay informed about: Isolation transformers