[Ben Hanson]

Hi everyone, hoping some of the experts can provide some feedback here. I've
done the requisite Google-ing and have a clearer picture but I'm still not
as certain as I'd like to be before making some purchases.

I have recently relocated to the UK from the States. To save from having to
buy a ton of new IEC-to-UK power cables (for the gear that supports 230V) I
want to pick up two or three stepdown transformers so that I can just
continue to power my gear off of 110V. This gear will sit in my studio and
not be moved around.

Stepdown transformers are common here because UK construction sites by law
must stepdown to 110V for safety reasons (good random trivia question to
remember). I've found several reputable companies that manufacture their own
stepdown transformers, up to 2K - 3K kVA, which have one or two US outlets
on the output side, which makes it all really easy.

My question is, I can get them in the laminated or torroidal variety, and it
isn't clear to me that one is necessarily better than the other (for this
particular application...I understand that conceptually torroidal
transformers are "better"). The hum of the transformer itself is one
consideration. Another is electromagnetic interference and its effect on
things like signals in unshielded audio cabling. Torroidal transformers are
better in both of these regards, but what I'm not sure about is how much
this really matters in this particular usage...is it something to be
concerned about? Is it not really a concern unless I'm running cables
underneath the transformer, etc?

The second question is, does one or the other type of transformer have any
particular benefit for providing continuous power? For example, many of the
stepdown transformers here seem to be made for intermittent use, i.e. they
are made for construction sites where a drill or a compressor kicks on and
then back off, etc...but not for powering equipment close to the rated
wattage of the transformer for long, extended periods of time. Will a
laminated or torroidal transformer inherently perform better in that sort of
"continuous" usage?

Thanks in advance for the help.

-Ben

** Posted from http://www.teranews.com **

[Don Pearce]

Ben Hanson wrote:
Hi everyone, hoping some of the experts can provide some feedback here.
I've done the requisite Google-ing and have a clearer picture but I'm
still not as certain as I'd like to be before making some purchases.

I have recently relocated to the UK from the States. To save from having
to buy a ton of new IEC-to-UK power cables (for the gear that supports
230V) I want to pick up two or three stepdown transformers so that I can
just continue to power my gear off of 110V. This gear will sit in my
studio and not be moved around.

Stepdown transformers are common here because UK construction sites by
law must stepdown to 110V for safety reasons (good random trivia
question to remember). I've found several reputable companies that
manufacture their own stepdown transformers, up to 2K - 3K kVA, which
have one or two US outlets on the output side, which makes it all really
easy.

My question is, I can get them in the laminated or torroidal variety,
and it isn't clear to me that one is necessarily better than the other
(for this particular application...I understand that conceptually
torroidal transformers are "better"). The hum of the transformer itself
is one consideration. Another is electromagnetic interference and its
effect on things like signals in unshielded audio cabling. Torroidal
transformers are better in both of these regards, but what I'm not sure
about is how much this really matters in this particular usage...is it
something to be concerned about? Is it not really a concern unless I'm
running cables underneath the transformer, etc?

The second question is, does one or the other type of transformer have
any particular benefit for providing continuous power? For example, many
of the stepdown transformers here seem to be made for intermittent use,
i.e. they are made for construction sites where a drill or a compressor
kicks on and then back off, etc...but not for powering equipment close
to the rated wattage of the transformer for long, extended periods of
time. Will a laminated or torroidal transformer inherently perform
better in that sort of "continuous" usage?

Thanks in advance for the help.


Provided you keep them as far as you can from any unshielded cables,
that aspect shouldn't matter. As for the other stuff - weight is where
its at; the more iron the better. Toroidal has a better iron path, but
it is easier to put a good winding on a standard bobbin in a set of E/I
laminations. Finally, if you can get to try them on heavy loads, go for
the one that stays coolest.

Since you don't need the safety isolation for this job, you might want
to see if you can find an autotransformer - a single winding with a
voltage tap at 110V. That should be cheaper and lighter for the same
performance.

d

[Ben Hanson]

Hi Don...unless you're a very early riser I'm assuming that you are also
here in the UK (or parts eastward)...are you familiar with these people at
all? They seem to hand-assemble all their stuff and the ones in the silver
varnish finish look nice (not that how they look really matters but the
all-metal casing will be good at disippating heat). I've spoken with them
twice and they sound very knowledgeable and have been helpful. They
guarantee that even their "intermittent" transformers will power at max load
for hours (they rate their "contunuous" usage transformers for things thata
re literally 24x7, like powering a fridge-freezer), and are virtually silent
unless you put your ear on them.

http://www.newmarket-transformers.co...ansformers.asp

-Ben



"Don Pearce" wrote in message
et...
Ben Hanson wrote:
Hi everyone, hoping some of the experts can provide some feedback here.
I've done the requisite Google-ing and have a clearer picture but I'm
still not as certain as I'd like to be before making some purchases.

I have recently relocated to the UK from the States. To save from having
to buy a ton of new IEC-to-UK power cables (for the gear that supports
230V) I want to pick up two or three stepdown transformers so that I can
just continue to power my gear off of 110V. This gear will sit in my
studio and not be moved around.

Stepdown transformers are common here because UK construction sites by
law must stepdown to 110V for safety reasons (good random trivia question
to remember). I've found several reputable companies that manufacture
their own stepdown transformers, up to 2K - 3K kVA, which have one or two
US outlets on the output side, which makes it all really easy.

My question is, I can get them in the laminated or torroidal variety, and
it isn't clear to me that one is necessarily better than the other (for
this particular application...I understand that conceptually torroidal
transformers are "better"). The hum of the transformer itself is one
consideration. Another is electromagnetic interference and its effect on
things like signals in unshielded audio cabling. Torroidal transformers
are better in both of these regards, but what I'm not sure about is how
much this really matters in this particular usage...is it something to be
concerned about? Is it not really a concern unless I'm running cables
underneath the transformer, etc?

The second question is, does one or the other type of transformer have
any particular benefit for providing continuous power? For example, many
of the stepdown transformers here seem to be made for intermittent use,
i.e. they are made for construction sites where a drill or a compressor
kicks on and then back off, etc...but not for powering equipment close to
the rated wattage of the transformer for long, extended periods of time.
Will a laminated or torroidal transformer inherently perform better in
that sort of "continuous" usage?

Thanks in advance for the help.


Provided you keep them as far as you can from any unshielded cables, that
aspect shouldn't matter. As for the other stuff - weight is where its at;
the more iron the better. Toroidal has a better iron path, but it is
easier to put a good winding on a standard bobbin in a set of E/I
laminations. Finally, if you can get to try them on heavy loads, go for
the one that stays coolest.

Since you don't need the safety isolation for this job, you might want to
see if you can find an autotransformer - a single winding with a voltage
tap at 110V. That should be cheaper and lighter for the same performance.

d

** Posted from http://www.teranews.com **

[Don Pearce]

Ben Hanson wrote:
Hi Don...unless you're a very early riser I'm assuming that you are also
here in the UK (or parts eastward)...are you familiar with these people
at all? They seem to hand-assemble all their stuff and the ones in the
silver varnish finish look nice (not that how they look really matters
but the all-metal casing will be good at disippating heat). I've spoken
with them twice and they sound very knowledgeable and have been helpful.
They guarantee that even their "intermittent" transformers will power at
max load for hours (they rate their "contunuous" usage transformers for
things thata re literally 24x7, like powering a fridge-freezer), and are
virtually silent unless you put your ear on them.


Hi Ben, yes I've used them in the past and they make good stuff. If you
work out the necessary rating by adding together the power stated on the
labels on all your kit, you will find there is still plenty of margin to
leave the transformer running cool. If they make what you need, I'd say
go for it.

d (London, so no, not an early riser)

[Mike Rivers]

Ben Hanson wrote:

I have recently relocated to the UK from the States. To save from having
to buy a ton of new IEC-to-UK power cables (for the gear that supports
230V) I want to pick up two or three stepdown transformers so that I can
just continue to power my gear off of 110V.

I've found several reputable companies that
manufacture their own stepdown transformers, up to 2K - 3K kVA, which
have one or two US outlets on the output side, which makes it all really
easy.

How much do UK IEC power cables cost over there? And how many (honestly)
is "a ton?" Over here, a 2-3 KVA 2:1 transformer (a real isolation
transformer, not an autotransformer) would cost about as much as about
100 IEC power cables, even at retail prices. What are you looking at
that would save you money?

..I understand that conceptually
torroidal transformers are "better"). The hum of the transformer itself
is one consideration. Another is electromagnetic interference and its
effect on things like signals in unshielded audio cabling. Torroidal
transformers are better in both of these regards, but what I'm not sure
about is how much this really matters in this particular usage...

It depends on where you put it. If it's in the basement and the studio
is upstairs, no problem. If it's under the console or in the base of a
rack, you might be concerned about a strong magnetic field. Not that
cables or devices a couple of feet away will be affected, but it's too
easy to dangle a cable too close to a transformer. Even a wall wart has
been known to cause hum problems when an audio cable gets too close to it.

The second question is, does one or the other type of transformer have
any particular benefit for providing continuous power? For example, many
of the stepdown transformers here seem to be made for intermittent use,

This is why you need to spend about a grand for one. If you get a $100
one (which will indeed be cheaper than a ton of power cords) you could
be buying trouble.




--
If you e-mail me and it bounces, use your secret decoder ring and reach
me he
double-m-eleven-double-zero at yahoo -- I'm really Mike Rivers
)

[Adrian Tuddenham]

Ben Hanson wrote:


I have recently relocated to the UK from the States. To save from having to
buy a ton of new IEC-to-UK power cables (for the gear that supports 230V) I
want to pick up two or three stepdown transformers so that I can just
continue to power my gear off of 110V.
[...]
My question is, I can get them in the laminated or torroidal variety, and it
isn't clear to me that one is necessarily better than the other (for this
particular application..
[...]

There is occasionally a problem with switch-on surges which is worse
with toroidal types than EI types. This can manifest itself as an
annoying intermittent fault, which occasionally results in a blown fuse
or trip, for no obvious reason.

At the instant of the mains cycle when the power is switched off, the
core of a transformer will be magnetised to some degree or other. A
toroidal transformer with no air gaps in its core is more likely to
retain this level of magnetism than a set of EI cores would.

When the mains is next switched back on, if the polarity happens to be
in the same direction as the magnetism already in the core, the iron
will be driven into magnetic saturation. The iron can take no further
part in the operation of the transformer until it has be demagnetised by
the opposite cycle and settled back to normal operation. This mans that
the transformer is not behaving like an iron-cored transformer for half
a cycle of the mains, it behaves like a coil of air-cored copper wire
and draws a huge current.

This effect will be worse in a torid because they often run closer to
saturation. The larger the transformer, the lower the resistance of the
primary winding - so the current will be higher and likelihood of
blowing fuses will be greater.


--
~ Adrian Tuddenham ~
(Remove the ".invalid"s and add ".co.uk" to reply)
www.poppyrecords.co.uk

[Scott Dorsey]

Ben Hanson wrote:
My question is, I can get them in the laminated or torroidal variety, and it
isn't clear to me that one is necessarily better than the other (for this
particular application...I understand that conceptually torroidal
transformers are "better"). The hum of the transformer itself is one
consideration. Another is electromagnetic interference and its effect on
things like signals in unshielded audio cabling. Torroidal transformers are
better in both of these regards, but what I'm not sure about is how much
this really matters in this particular usage...is it something to be
concerned about? Is it not really a concern unless I'm running cables
underneath the transformer, etc?

A good EI-core transformer will beat a crappy toroid. A good toroid will
beat a crappy EI-core transformer.

What you want is a transformer that has good regulation, so the voltage on
the secondary doesn't change a lot with load. And you want a transformer
that is effectively a low-pass filter, so high frequency trash doesn't make
it through it.

It doesn't matter what technology is used to make the core, it matters more
how big the core is, what it's made of, and how careful the design work is.

The second question is, does one or the other type of transformer have any
particular benefit for providing continuous power? For example, many of the
stepdown transformers here seem to be made for intermittent use, i.e. they
are made for construction sites where a drill or a compressor kicks on and
then back off, etc...but not for powering equipment close to the rated
wattage of the transformer for long, extended periods of time.

We call these ratings "fraudulent" and the products "crap." Don't buy
crap.

Will a
laminated or torroidal transformer inherently perform better in that sort of
"continuous" usage?

No, crappy transformers are crappy no matter what shape core they use.
Do not buy crappy transformers. Don't buy ANY Chinese-made transformers..
they seem unable to get decent quality core steels there. Go to a real
industrial electrical supply house and ask about Siemens dry transformers
for permanent install use. In the US we also get Acme and Square-D brand
in the same market but in the UK I suspect Siemens and Brown-Boveri will
be more common. Don't buy crap.

If possible, get a real transformer with a primary and secondary rather
than an autotransformer. It will be twice as heavy and cost twice as
much, since twice the actual power needs to be going through the core,
but it will give you isolation and make your life better. All of
the construction site crappo jobs are autotransformers, which is fine
if you're running a big electric saw but not a very good idea for
precision audio electronics.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Scott Dorsey]

Mike Rivers wrote:
Ben Hanson wrote:

I have recently relocated to the UK from the States. To save from having
to buy a ton of new IEC-to-UK power cables (for the gear that supports
230V) I want to pick up two or three stepdown transformers so that I can
just continue to power my gear off of 110V.

I've found several reputable companies that
manufacture their own stepdown transformers, up to 2K - 3K kVA, which
have one or two US outlets on the output side, which makes it all really
easy.

How much do UK IEC power cables cost over there? And how many (honestly)
is "a ton?" Over here, a 2-3 KVA 2:1 transformer (a real isolation
transformer, not an autotransformer) would cost about as much as about
100 IEC power cables, even at retail prices. What are you looking at
that would save you money?

Do people pay actual money for IEC cables? Ask your local computer guy...
he will have bucketloads of them. Hell, I have bucketloads of them with
BS1363 plugs and Europlugs that came with equipment, even, and I am in the US.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Richard Crowley]

"Scott Dorsey" wrote ...
Do people pay actual money for IEC cables? Ask your local computer guy...
he will have bucketloads of them. Hell, I have bucketloads of them with
BS1363 plugs and Europlugs that came with equipment, even, and I am in the
US.

I've paid for 15-foot IEC cables. (The ones I use on my
powered PA speakers.) The longer lengths aren't commonly
available just lying about.

[Laurence Payne[_2_]]

On Wed, 27 Aug 2008 08:15:48 -0700, "Richard Crowley"
wrote:

Do people pay actual money for IEC cables? Ask your local computer guy...
he will have bucketloads of them. Hell, I have bucketloads of them with
BS1363 plugs and Europlugs that came with equipment, even, and I am in the
US.

I've paid for 15-foot IEC cables. (The ones I use on my
powered PA speakers.) The longer lengths aren't commonly
available just lying about.

Have you always had this genius for unearthing a special case to
contridict ANY statement? :-)

[Mike Rivers]

Richard Crowley wrote:

I've paid for 15-foot IEC cables. (The ones I use on my
powered PA speakers.) The longer lengths aren't commonly
available just lying about.

Same for short cables. I have a couple of 2' cables that I use on my
workbench. I think I paid $3 for them at a hamfest where the same guy
was selling standard length (6' or so) cables for what seems to be the
standard hamfest price of a dollar. Even if you have to buy one at Radio
Shack in an emergency, they're only $9.

--
If you e-mail me and it bounces, use your secret decoder ring and reach
me he
double-m-eleven-double-zero at yahoo -- I'm really Mike Rivers
)

[Joe Kotroczo]

On 27/08/08 13:26, in article ORatk.869$p72.769@trnddc05, "Mike Rivers"
wrote:

(...)
How much do UK IEC power cables cost over there?

£5.99 at Maplin. Translates into $10.92

And how many (honestly) is "a ton?"

Good question. Don't know about the OP, but when I'll relocate, I'll need at
least 30 of them.

But I might just put BS1363 plugs an my multi-plugs... The BS1363 plugs are
only £1.29 ($2.35)



--
Joe Kotroczo

[Laurence Payne[_2_]]

On Fri, 29 Aug 2008 21:57:54 +0200, Joe Kotroczo
wrote:

How much do UK IEC power cables cost over there?

£5.99 at Maplin. Translates into $10.92

Also translates into about half that almost anywhere else. Or free
for the asking if you're lucky.

[Joe Kotroczo]

On 29/08/08 22:05, in article ,
"Laurence Payne" wrote:

On Fri, 29 Aug 2008 21:57:54 +0200, Joe Kotroczo
wrote:

How much do UK IEC power cables cost over there?

£5.99 at Maplin. Translates into $10.92

Also translates into about half that almost anywhere else. Or free
for the asking if you're lucky.

Hey, I haven't moved to the UK yet. But 30 of them for free? Maybe you'll
point me to the place when I'm there? (Really soon now....)


--
Joe Kotroczo

[Adrian Tuddenham]

Joe Kotroczo wrote:

On 29/08/08 22:05, in article ,
"Laurence Payne" wrote:

On Fri, 29 Aug 2008 21:57:54 +0200, Joe Kotroczo
wrote:

How much do UK IEC power cables cost over there?

£5.99 at Maplin. Translates into $10.92

Also translates into about half that almost anywhere else. Or free
for the asking if you're lucky.

Hey, I haven't moved to the UK yet. But 30 of them for free? Maybe you'll
point me to the place when I'm there? (Really soon now....)


If you don't mind secondhand cables (test them thoroughly before use),
there is a system called 'Freecycle' in most of the larger towns in the
UK, where you can use e-mail to offer and request surplus stuff so as to
prevent it from going into landfill. Often the items are well past
being useful, but occasionally they are brand-new-but-unwanted and are
being thrown out from a factory or office.

Local independent hardware or electrical shops are not common nowadays;
but if you can find one, the prices will be very competitive. Large
national DIY stores often have very low prices with low quality to
match.
RS Components (RadioSpares, not Radio Shack) supply a huge range of
electronic and electrical stuff by post; their delivery is superb but
their prices are high.

If you are doing a lot of electrical fitting-out, you might find it
worthwhile to open an account at a local electrical wholesalers or just
find one which accepts cash over the counter. In smaller towns,
personal recommendation is a good way of finding the best places to buy
things, but it may take a while to become accepted as a straight dealer
and gain the confidence of the community (it varies considerably from
place to place, England is compact but each area has its own distinctive
character).

Double-check and then check again that each appliance really is set to
work off 240v mains. Any mistake will be very expensive. There also
used to be in issue with 60c/s mains transformers overheating on 50c/s
supplies, but that was a long time ago and I don't suppose you will ever
encounter a problem like that.

Earths must be properly connected. The first time you receive a 240v
shock, you will be forcibly reminded of the difference between UK and US
supplies.


--
~ Adrian Tuddenham ~
(Remove the ".invalid"s and add ".co.uk" to reply)
www.poppyrecords.co.uk

[Joe Kotroczo]

On 30/08/08 12:17, in article
nvalid, "Adrian Tuddenham"
wrote:

Joe Kotroczo wrote:

On 29/08/08 22:05, in article ,
"Laurence Payne" wrote:

On Fri, 29 Aug 2008 21:57:54 +0200, Joe Kotroczo
wrote:

How much do UK IEC power cables cost over there?

£5.99 at Maplin. Translates into $10.92

Also translates into about half that almost anywhere else. Or free
for the asking if you're lucky.

Hey, I haven't moved to the UK yet. But 30 of them for free? Maybe you'll
point me to the place when I'm there? (Really soon now....)


If you don't mind secondhand cables (test them thoroughly before use),
there is a system called 'Freecycle' in most of the larger towns in the
UK, where you can use e-mail to offer and request surplus stuff so as to
prevent it from going into landfill. Often the items are well past
being useful, but occasionally they are brand-new-but-unwanted and are
being thrown out from a factory or office.

Local independent hardware or electrical shops are not common nowadays;
but if you can find one, the prices will be very competitive. Large
national DIY stores often have very low prices with low quality to
match.
RS Components (RadioSpares, not Radio Shack) supply a huge range of
electronic and electrical stuff by post; their delivery is superb but
their prices are high.

If you are doing a lot of electrical fitting-out, you might find it
worthwhile to open an account at a local electrical wholesalers or just
find one which accepts cash over the counter. In smaller towns,
personal recommendation is a good way of finding the best places to buy
things, but it may take a while to become accepted as a straight dealer
and gain the confidence of the community (it varies considerably from
place to place, England is compact but each area has its own distinctive
character).

Good info. Thanks!

Double-check and then check again that each appliance really is set to
work off 240v mains. Any mistake will be very expensive. There also
used to be in issue with 60c/s mains transformers overheating on 50c/s
supplies, but that was a long time ago and I don't suppose you will ever
encounter a problem like that.

Earths must be properly connected. The first time you receive a 240v
shock, you will be forcibly reminded of the difference between UK and US
supplies.

Err... I'm from an 230V Europlug country actually. And I've had the
experience of a 230V shock... Unpleasant.


--
Joe Kotroczo

[Adrian Tuddenham]

Joe Kotroczo wrote:

On 30/08/08 12:17, in article
nvalid, "Adrian Tuddenham"
wrote:


Double-check and then check again that each appliance really is set to
work off 240v mains. Any mistake will be very expensive. There also
used to be in issue with 60c/s mains transformers overheating on 50c/s
supplies, but that was a long time ago and I don't suppose you will ever
encounter a problem like that.

Earths must be properly connected. The first time you receive a 240v
shock, you will be forcibly reminded of the difference between UK and US
supplies.

Err... I'm from an 230V Europlug country actually. And I've had the
experience of a 230V shock... Unpleasant.

Sorry, I incorrectly assumed you were from the USA.

Surprisingly a 500v shock (across one hand) doesn't feel significantly
worse than a 240v shock at the instant it occurs, but the resulting
damage is more extensive so it hurts a lot more soon afterwards and
takes longer to grow out. The smell of burning flesh is never pleasant,
but when you can see the smoke coming from your own fingertips, it is a
lot worse.


--
~ Adrian Tuddenham ~
(Remove the ".invalid"s and add ".co.uk" to reply)
www.poppyrecords.co.uk

[Anahata]

On Fri, 29 Aug 2008 21:05:40 +0100, Laurence Payne wrote:

On Fri, 29 Aug 2008 21:57:54 +0200, Joe Kotroczo
wrote:

How much do UK IEC power cables cost over there?

£5.99 at Maplin. Translates into $10.92

Also translates into about half that almost anywhere else. Or free for
the asking if you're lucky.

http://www.scan.co.uk/Product.aspx?WebProductId=1838
(£1.65 inc VAT)
Postage is a bit high, but if you're buying a couple dozen it's not a bad
deal.

--
Anahata
-+- http://www.treewind.co.uk
Home: 01638 720444 Mob: 07976 263827