does the cross sectional shape of the transformer winding wire
have significant performance changes compared with a round wire
winding with same crossectional area ?

by shape i mean square or rectangle or even triangular ?

thanks for any info ideas and educational comments,
robb

On Mar 7, 4:50=A0pm, "robb" <s...@where.on.net> wrote:
> does the cross sectional shape of the transformer winding wire
> have significant performance changes compared with =A0a round wire
> winding with same crossectional area ?
>
> by shape i mean square or rectangle or even triangular ?

Round wire does not pack as tightly (tesselate) as triangular,
rectangular or hexagonal wire might, so going with round wire does
have a cost.

I believe some applications go to the trouble of using other
crossections - the only example that comes to mind are Bittner
magnets, where the current carrying path is made of helical sheets
with holes in the them - the cooling water takes the short path
through the holes, while the current takes the longer, spiral path
theough the sheets of copper.

--
Bill Sloman, Nijmegen

In article <82e0903f-6e19-49aa-980e-d89aa60ab2fe@v3g2000hsc.googlegroups.com>, bill.sloman@ieee.org wrote:
>On Mar 7, 4:50=A0pm, "robb" <s...@where.on.net> wrote:
>> does the cross sectional shape of the transformer winding wire
>> have significant performance changes compared with =A0a round wire
>> winding with same crossectional area ?
>>
>> by shape i mean square or rectangle or even triangular ?
>
>Round wire does not pack as tightly (tesselate) as triangular,
>rectangular or hexagonal wire might, so going with round wire does
>have a cost.

I am familiar with square or rectangular wire for winding voice coils, as well
as flat aluminum ribbon voice coils.

greg

bill.sloman@ieee.org wrote:
>
> On Mar 7, 4:50 pm, "robb" <s...@where.on.net> wrote:
> > does the cross sectional shape of the transformer winding wire
> > have significant performance changes compared with a round wire
> > winding with same crossectional area ?
> >
> > by shape i mean square or rectangle or even triangular ?
>
> Round wire does not pack as tightly (tesselate) as triangular,
> rectangular or hexagonal wire might, so going with round wire does
> have a cost.

Increased leakage flux being one cost.

> I believe some applications go to the trouble of using other
> crossections - the only example that comes to mind are Bittner
> magnets, where the current carrying path is made of helical sheets
> with holes in the them - the cooling water takes the short path
> through the holes, while the current takes the longer, spiral path
> theough the sheets of copper.

Large utility transformers (and generators) are wound with
square/rectangular conductors.

> --
> Bill Sloman, Nijmegen

--
Paul Hovnanian paul@hovnanian.com
-----------------------------------------------------------------------
Procrastinators: The leaders for tomorrow.

bill.sloman@ieee.org wrote:

> On Mar 7, 4:50 pm, "robb" <s...@where.on.net> wrote:
> > does the cross sectional shape of the transformer winding wire
> > have significant performance changes compared with a round wire
> > winding with same crossectional area ?
> >
> > by shape i mean square or rectangle or even triangular ?
>
> Round wire does not pack as tightly (tesselate) as triangular,
> rectangular or hexagonal wire might, so going with round wire does
> have a cost.
>
> I believe some applications go to the trouble of using other
> crossections - the only example that comes to mind are Bittner
> magnets, where the current carrying path is made of helical sheets
> with holes in the them - the cooling water takes the short path
> through the holes, while the current takes the longer, spiral path
> theough the sheets of copper.

Some louspeaker voice coils use rectangular wire.

Graham

On Mar 8, 5:57=A0am, Eeyore <rabbitsfriendsandrelati...@hotmail.com>
wrote:
> bill.slo...@ieee.org wrote:
> > On Mar 7, 4:50 pm, "robb" <s...@where.on.net> wrote:
> > > does the cross sectional shape of the transformer winding wire
> > > have significant performance changes compared with =A0a round wire
> > > winding with same crossectional area ?
>
> > > by shape i mean square or rectangle or even triangular ?
>
> > Round wire does not pack as tightly (tesselate) as triangular,
> > rectangular or hexagonal wire might, so going with round wire does
> > have a cost.
>
> > I believe some applications go to the trouble of using other
> > crossections - the only example that comes to mind are Bittner
> > magnets, where the current carrying path is made of helical sheets
> > with holes in the them - the cooling water takes the short path
> > through the holes, while the current takes the longer, spiral path
> > theough the sheets of copper.
>
> Some louspeaker voice coils use rectangular wire.
>
> Graham- Hide quoted text -
>
> - Show quoted text -

I have never seen square or rectangular enamelled wires. Are the
corners rounded?

Allen

Allen Bong wrote:

> Eeyore wrote:
> > bill.slo...@ieee.org wrote:
> > > On Mar 7, 4:50 pm, "robb" <s...@where.on.net> wrote:
> > > > does the cross sectional shape of the transformer winding wire
> > > > have significant performance changes compared with a round wire
> > > > winding with same crossectional area ?
> >
> > > > by shape i mean square or rectangle or even triangular ?
> >
> > > Round wire does not pack as tightly (tesselate) as triangular,
> > > rectangular or hexagonal wire might, so going with round wire does
> > > have a cost.
> >
> > > I believe some applications go to the trouble of using other
> > > crossections - the only example that comes to mind are Bittner
> > > magnets, where the current carrying path is made of helical sheets
> > > with holes in the them - the cooling water takes the short path
> > > through the holes, while the current takes the longer, spiral path
> > > theough the sheets of copper.
> >
> > Some louspeaker voice coils use rectangular wire.
>
>
> I have never seen square or rectangular enamelled wires. Are the
> corners rounded?

I haven't seen it on a reel so I couldn't tell you. I imagine it might
well be.

Graham

"Allen Bong"

" I have never seen square or rectangular enamelled wires. Are the
corners rounded? "


** Well, with the smaller gauges at least and to the un-aided eye - the
corners look sharp.

Under sufficient magnification, they may appear quite rounded.

Got any more ambiguous questions ?



....... Phil

Allen Bong wrote:

> I have never seen square or rectangular enamelled wires. Are the
> corners rounded?

Yes. See corner radius spec:
http://www.mwswire.com/square.htm

--
Regards,

John Popelish

On Fri, 07 Mar 2008 10:50:01 -0500, robb wrote:

> does the cross sectional shape of the transformer winding wire
> have significant performance changes compared with a round wire
> winding with same crossectional area ?
>
> by shape i mean square or rectangle or even triangular ?
>
> thanks for any info ideas and educational comments,

I don't know how significant - the area of a, say, 2mm square
is almost 4 mm^2 (a litle less because of the rounded corners),
but round wire 2mm diameter has an area of pi * r^2, or 3.14
mm^2, which actually does look fairly significant.

Bottom line, you can get more copper into the winding window.

Cheers!
Rich

On 3=D4=C27=C8=D5, =CF=C2=CE=E711=CA=B150=B7=D6, "robb" <s...@where.on.net> =
wrote:
> does the cross sectional shape of the transformer winding wire
> have significant performance changes compared with a round wire
> winding with same crossectional area ?
>
> by shape i mean square or rectangle or even triangular ?
>
> thanks for any info ideas and educational comments,
> robb



Do you want access to China's massive pool of electronic
manufacturers... but lack the time to contact suppliers, negotiate
contracts, arrange shipping or monitor product quality? Don't worry -
Let seriouswholesale deal with all that for you.

*Check out the huge range of Gadgets, MP3 / MP4 Players, Car DVD /
Audio, and Computer Accessories now by visiting the online wholesale
catalog at seriouswholesale. com You'll have peace of mind thanks to
the seriouswholesale Quality Control, 12-month Warranty on all
products, and easy secure payment by credit card through Paypal.

Selling on eBay or your own online store? Send products direct from
our warehouse to your customers using our unique drop-shipping
service. You can profit by selling hundreds of different products,
without holding any of your own inventory! Any questions you have will
be answered by the seriouswholesale English-speaking customer support
team... Their aim is to make your China electronics importing business
easier to run than ever before.

Welcome to http://www.seriouswholesale.com.

seriouswholesale - Buy from the source, profit without the hassle.

- 12 Months Warranty - No minimum order restrictions - Drop-shipping
with no additional fee - Pay by safely by PayPal seriouswholesale
Wholesale Co., Ltd.: Chinas original and best online electronics
wholesaler & drop-shipper: seriouswholesale. com

On 3=D4=C28=C8=D5, =C9=CF=CE=E712=CA=B119=B7=D6, bill.slo...@ieee.org wrote:=

> On Mar 7, 4:50 pm, "robb" <s...@where.on.net> wrote:
>
> > does the cross sectional shape of the transformer winding wire
> > have significant performance changes compared with a round wire
> > winding with same crossectional area ?
>
> > by shape i mean square or rectangle or even triangular ?
>
> Round wire does not pack as tightly (tesselate) as triangular,
> rectangular or hexagonal wire might, so going with round wire does
> have a cost.
>
> I believe some applications go to the trouble of using other
> crossections - the only example that comes to mind are Bittner
> magnets, where the current carrying path is made of helical sheets
> with holes in the them - the cooling water takes the short path
> through the holes, while the current takes the longer, spiral path
> theough the sheets of copper.
>
> --
> Bill Sloman, Nijmegen



Do you want access to China's massive pool of electronic
manufacturers... but lack the time to contact suppliers, negotiate
contracts, arrange shipping or monitor product quality? Don't worry -
Let seriouswholesale deal with all that for you.

*Check out the huge range of Gadgets, MP3 / MP4 Players, Car DVD /
Audio, and Computer Accessories now by visiting the online wholesale
catalog at seriouswholesale. com You'll have peace of mind thanks to
the seriouswholesale Quality Control, 12-month Warranty on all
products, and easy secure payment by credit card through Paypal.

Selling on eBay or your own online store? Send products direct from
our warehouse to your customers using our unique drop-shipping
service. You can profit by selling hundreds of different products,
without holding any of your own inventory! Any questions you have will
be answered by the seriouswholesale English-speaking customer support
team... Their aim is to make your China electronics importing business
easier to run than ever before.

Welcome to http://www.seriouswholesale.com.

seriouswholesale - Buy from the source, profit without the hassle.

- 12 Months Warranty - No minimum order restrictions - Drop-shipping
with no additional fee - Pay by safely by PayPal seriouswholesale
Wholesale Co., Ltd.: Chinas original and best online electronics
wholesaler & drop-shipper: seriouswholesale. com

On 3=D4=C28=C8=D5, =C9=CF=CE=E712=CA=B147=B7=D6, zekfr...@zekfrivolous.com (=
GregS) wrote:
> In article <82e0903f-6e19-49aa-980e-d89aa60ab...@v3g2000hsc.googlegroups.c=
om>, bill.slo...@ieee.org wrote:
>
> >On Mar 7, 4:50=3DA0pm, "robb" <s...@where.on.net> wrote:
> >> does the cross sectional shape of the transformer winding wire
> >> have significant performance changes compared with =3DA0a round wire
> >> winding with same crossectional area ?
>
> >> by shape i mean square or rectangle or even triangular ?
>
> >Round wire does not pack as tightly (tesselate) as triangular,
> >rectangular or hexagonal wire might, so going with round wire does
> >have a cost.
>
> I am familiar with square or rectangular wire for winding voice coils, as =
well
> as flat aluminum ribbon voice coils.
>
> greg



Do you want access to China's massive pool of electronic
manufacturers... but lack the time to contact suppliers, negotiate
contracts, arrange shipping or monitor product quality? Don't worry -
Let seriouswholesale deal with all that for you.

*Check out the huge range of Gadgets, MP3 / MP4 Players, Car DVD /
Audio, and Computer Accessories now by visiting the online wholesale
catalog at seriouswholesale. com You'll have peace of mind thanks to
the seriouswholesale Quality Control, 12-month Warranty on all
products, and easy secure payment by credit card through Paypal.

Selling on eBay or your own online store? Send products direct from
our warehouse to your customers using our unique drop-shipping
service. You can profit by selling hundreds of different products,
without holding any of your own inventory! Any questions you have will
be answered by the seriouswholesale English-speaking customer support
team... Their aim is to make your China electronics importing business
easier to run than ever before.

Welcome to http://www.seriouswholesale.com.

seriouswholesale - Buy from the source, profit without the hassle.

- 12 Months Warranty - No minimum order restrictions - Drop-shipping
with no additional fee - Pay by safely by PayPal seriouswholesale
Wholesale Co., Ltd.: Chinas original and best online electronics
wholesaler & drop-shipper: seriouswholesale. com

On 3=D4=C28=C8=D5, =C9=CF=CE=E72=CA=B139=B7=D6, "Paul Hovnanian P.E." <pa...=
@seanet.com> wrote:
> bill.slo...@ieee.org wrote:
>
> > On Mar 7, 4:50 pm, "robb" <s...@where.on.net> wrote:
> > > does the cross sectional shape of the transformer winding wire
> > > have significant performance changes compared with a round wire
> > > winding with same crossectional area ?
>
> > > by shape i mean square or rectangle or even triangular ?
>
> > Round wire does not pack as tightly (tesselate) as triangular,
> > rectangular or hexagonal wire might, so going with round wire does
> > have a cost.
>
> Increased leakage flux being one cost.
>
> > I believe some applications go to the trouble of using other
> > crossections - the only example that comes to mind are Bittner
> > magnets, where the current carrying path is made of helical sheets
> > with holes in the them - the cooling water takes the short path
> > through the holes, while the current takes the longer, spiral path
> > theough the sheets of copper.
>
> Large utility transformers (and generators) are wound with
> square/rectangular conductors.
>
> > --
> > Bill Sloman, Nijmegen
>
> --
> Paul Hovnanian p...@hovnanian.com
> -----------------------------------------------------------------------
> Procrastinators: The leaders for tomorrow.



Do you want access to China's massive pool of electronic
manufacturers... but lack the time to contact suppliers, negotiate
contracts, arrange shipping or monitor product quality? Don't worry -
Let seriouswholesale deal with all that for you.

*Check out the huge range of Gadgets, MP3 / MP4 Players, Car DVD /
Audio, and Computer Accessories now by visiting the online wholesale
catalog at seriouswholesale. com You'll have peace of mind thanks to
the seriouswholesale Quality Control, 12-month Warranty on all
products, and easy secure payment by credit card through Paypal.

Selling on eBay or your own online store? Send products direct from
our warehouse to your customers using our unique drop-shipping
service. You can profit by selling hundreds of different products,
without holding any of your own inventory! Any questions you have will
be answered by the seriouswholesale English-speaking customer support
team... Their aim is to make your China electronics importing business
easier to run than ever before.

Welcome to http://www.seriouswholesale.com.

seriouswholesale - Buy from the source, profit without the hassle.

- 12 Months Warranty - No minimum order restrictions - Drop-shipping
with no additional fee - Pay by safely by PayPal seriouswholesale
Wholesale Co., Ltd.: Chinas original and best online electronics
wholesaler & drop-shipper: seriouswholesale. com

bill.sloman@ieee.org wrote:
> On Mar 7, 4:50 pm, "robb" <s...@where.on.net> wrote:
>> does the cross sectional shape of the transformer winding wire
>> have significant performance changes compared with a round wire
>> winding with same crossectional area ?
> Round wire does not pack as tightly (tesselate) as triangular,
> rectangular or hexagonal wire might, so going with round wire does
> have a cost.

When the new Australian Synchrotron (6km from here) was nearly finished,
they had an open day, and I noticed that many of the beam-bending
electromagnets used square wire, or square tube perhaps, perhaps 10mm
on a side, with rounded corners. Each wrap was separated by a 10mm air
gap as well, and I think adjacent turns were also separated. All
presumably for cooling while 1000's of amps were pumped through them.

Clifford Heath.

On Sat, 08 Mar 2008 21:18:44 +1100, Clifford Heath
<no@spam.please.net> wrote:

>bill.sloman@ieee.org wrote:
>> On Mar 7, 4:50 pm, "robb" <s...@where.on.net> wrote:
>>> does the cross sectional shape of the transformer winding wire
>>> have significant performance changes compared with a round wire
>>> winding with same crossectional area ?
>> Round wire does not pack as tightly (tesselate) as triangular,
>> rectangular or hexagonal wire might, so going with round wire does
>> have a cost.
>
>When the new Australian Synchrotron (6km from here) was nearly finished,
>they had an open day, and I noticed that many of the beam-bending
>electromagnets used square wire, or square tube perhaps, perhaps 10mm
>on a side, with rounded corners. Each wrap was separated by a 10mm air
>gap as well, and I think adjacent turns were also separated. All
>presumably for cooling while 1000's of amps were pumped through them.
>
>Clifford Heath.

Could well be tubing with chilled water, or LN2 pumped through them.

On Fri, 07 Mar 2008 22:41:47 GMT, Rich Grise <rich@example.net> wrote:

>On Fri, 07 Mar 2008 10:50:01 -0500, robb wrote:
>
>> does the cross sectional shape of the transformer winding wire
>> have significant performance changes compared with a round wire
>> winding with same crossectional area ?
>>
>> by shape i mean square or rectangle or even triangular ?
>>
>> thanks for any info ideas and educational comments,
>
>I don't know how significant - the area of a, say, 2mm square
>is almost 4 mm^2 (a litle less because of the rounded corners),
>but round wire 2mm diameter has an area of pi * r^2, or 3.14
>mm^2, which actually does look fairly significant.
>
>Bottom line, you can get more copper into the winding window.
>
>Cheers!
>Rich
>

And for some applications more, copper surface area which can be
important. Also at a 4 to pi ratio.

On Mar 7, 8:50=A0am, "robb" <s...@where.on.net> wrote:
> does the cross sectional shape of the transformer winding wire
> have significant performance changes compared with =A0a round wire
> winding with same crossectional area ?
>
> by shape i mean square or rectangle or even triangular ?
>
> thanks for any info ideas and educational comments,
> robb

No, certainly not enough to make your own round wire square. But for
the big boys (GE, ConEd, etc.) where a 2% return in efficiency is the
difference between howling at the moon or a big fat christmas bonus
then, yes.

I doubt any real cost benifits could be found in anything under 10
kilowatts in size. Are you trying to wind a 50 kilowatt toaster?
trading silly questions here.

On Mar 8, 11:18=A0am, Clifford Heath <n...@spam.please.net> wrote:
> bill.slo...@ieee.org wrote:
> > On Mar 7, 4:50 pm, "robb" <s...@where.on.net> wrote:
> >> does the cross sectional shape of the transformer winding wire
> >> have significant performance changes compared with =A0a round wire
> >> winding with same crossectional area ?
> > Round wire does not pack as tightly (tesselate) as triangular,
> > rectangular or hexagonal wire might, so going with round wire does
> > have a cost.
>
> When the new Australian Synchrotron (6km from here) was nearly finished,
> they had an open day, and I noticed that many of the beam-bending
> electromagnets used square wire, or square tube perhaps, perhaps 10mm
> on a side, with rounded corners. Each wrap was separated by a 10mm air
> gap as well, and I think adjacent turns were also separated. All
> presumably for cooling while 1000's of amps were pumped through them.

Spacing the turns by the wire dimension maximises the maximum
impedance of singe layer coil - a bigger gap decreases the inductance
more than it decreases the parallel capacitance and a smaller gap
doesn't increase the inductance as much as it increases the parallel
capacitance.

I'd expect water-cooled coils to use the Bitter geometry - a spiral
ribbon to carry the current between two coaxial non-conducting tubes
to carry the water with holes through the ribbon so that the water
could flow straight along the tube,

http://en.wikipedia.org/wiki/Bitter_solenoid

--
Bill Sloman, Nijmegen

<melee5@my-deja.com> wrote in message
news:49b3af8d-b675-4b1c-a39a-3d4c84f655b2@34g2000hsz.googlegroups.com...
On Mar 7, 8:50 am, "robb" <s...@where.on.net> wrote:
> > does the cross sectional shape of the transformer winding
wire
> > have significant performance changes compared with a round
wire
> > winding with same crossectional area ?
> >
>
> No, certainly not enough to make your own round wire square.
But for
> the big boys (GE, ConEd, etc.) where a 2% return in efficiency
is the
> difference between howling at the moon or a big fat christmas
bonus
> then, yes.
>
> I doubt any real cost benifits could be found in anything under
10
> kilowatts in size. Are you trying to wind a 50 kilowatt
toaster?
> trading silly questions here.
>

No, just curious....
when i read about tranny discussion and how or why someone might
go to the trouble of solving various problems in tranny winding ?
what kinds of problems are there and what are those solutions ?

In this case it might have been better to ask what parameters of
transformer operation are affected by the airgap between windings
and or how the windings are laid out including the performance
and parameters affected by the width anf height of the bobbin
that is frequently used in the mass produced trannies ?

Another curiousity is that the windings on transformers i have
opened seem quite sloppy wound and not evenly placed and i would
have thought that *even/neat* winding would have been a large
factor in transformer performance ? but maybe not ?

I would likely only be able to play with flatened / rectangular
or ribbon style wire anyways, as i imagine i would be
constructing a rather crude jig to shape the wire and a nicely
square wire would probably require something a little more
sophiticated than i would build. ( ie. steel bushings for rollers
pins with an adjustable gap)

thanks for the responses,
robb

On Mar 9, 8:54=A0pm, "robb" <s...@where.on.net> wrote:
> <mel...@my-deja.com> wrote in message
>
> news:49b3af8d-b675-4b1c-a39a-3d4c84f655b2@34g2000hsz.googlegroups.com...
> On Mar 7, 8:50 am, "robb" <s...@where.on.net> wrote:

<snip>

> Another curiousity is that the windings on transformers i have
> opened seem quite sloppy wound and not evenly placed and i would
> have thought that *even/neat* =A0winding would have been a large
> factor in transformer performance ? but maybe not ?

"Even/neat" looks nice, but only works with a few layers of fairly
thick wire.

> I would likely only be able to play with flatened / rectangular
> or ribbon style wire anyways, as i imagine i would be
> constructing a rather crude jig to shape the wire and a nicely
> square wire would probably require something a little more
> sophisticated than i would build. ( ie. steel bushings for rollers
> pins with an adjustable gap)

The layer of insulating enamel on the wire isn't going to survive this
kind of treatment. Figure on re-enamelling the wire after you've
reshaped it.

--
Bill Sloman, Nijmegen