torroidal transformer vendor

J

John Larkin

Guest
Hi,

Can anybody recommend a good source for a custom torroidal power
transformer? It will be roughly 50 VA; we need prototypes fast, and
maybe 100 per year after that.

There are about 200 suppliers listed in the EEM for torroids, and I
guess we'll spam lots of them with our spec, but I just wondered if
anybody has a vendor they especially like.

Thanks,

John
 
"John Larkin" <jjlarkin@highSNIPlandTHIStechPLEASEnology.com> wrote in
message news:848i01h41c5bf8pljo674lu1hl8c54sjq4@4ax.com...
Hi,

Can anybody recommend a good source for a custom torroidal power
transformer? It will be roughly 50 VA; we need prototypes fast, and
maybe 100 per year after that.

There are about 200 suppliers listed in the EEM for torroids, and I
guess we'll spam lots of them with our spec, but I just wondered if
anybody has a vendor they especially like.

Thanks,

John
Click to expand...
Hey John,
Rayco Electronics, lightning free prototypes, great production prices,
works for me.
http://www.raycoelectronics.com/index.html
Regards,
Harry
 
On Tue, 08 Feb 2005 20:39:08 GMT, "Harry Dellamano"
<harryd@tdsystems.org> wrote:

"John Larkin" <jjlarkin@highSNIPlandTHIStechPLEASEnology.com> wrote in
message news:848i01h41c5bf8pljo674lu1hl8c54sjq4@4ax.com...
Hi,

Can anybody recommend a good source for a custom torroidal power
transformer? It will be roughly 50 VA; we need prototypes fast, and
maybe 100 per year after that.

There are about 200 suppliers listed in the EEM for torroids, and I
guess we'll spam lots of them with our spec, but I just wondered if
anybody has a vendor they especially like.

Thanks,

John

Hey John,
Rayco Electronics, lightning free prototypes, great production prices,
works for me.
http://www.raycoelectronics.com/index.html
Regards,
Harry
Click to expand...
Thanks! We'll zap them our spec.

John
 
Hello John,

I had lots of good experience with Ulveco. There have been mergers et
cetera and I believe in the US it might now be:

http://www.amveco.com/

Regards, Joerg

http://www.analogconsultants.com
 
On Tue, 08 Feb 2005 21:58:18 GMT, Joerg
<notthisjoergsch@removethispacbell.net> wrote:

Hello John,

I had lots of good experience with Ulveco. There have been mergers et
cetera and I believe in the US it might now be:

http://www.amveco.com/

Regards, Joerg

http://www.analogconsultants.com
Click to expand...

Thanks. We'll add them to the bid list.

I hate magnetics.

John
 
Hello John,

I hate magnetics.
Click to expand...
Power transformers can be kind of boring. But I love ferrite stuff. You
can do cool things with those.

Regards, Joerg

http://www.analogconsultants.com
 
On Tue, 08 Feb 2005 23:55:36 GMT, Joerg
<notthisjoergsch@removethispacbell.net> wrote:

Hello John,

I hate magnetics.



Power transformers can be kind of boring. But I love ferrite stuff. You
can do cool things with those.
Click to expand...
I do like transmission-line transformers wound with micro-coax. We
just did a small 1:1 that puts a 60 volt pulse into 50 ohms with
rise/fall around 2 ns. That's fun.

John
 
On Tue, 08 Feb 2005 13:42:03 -0800, John Larkin
<jjlarkin@highSNIPlandTHIStechPLEASEnology.com> wrote:



without the thermistor gadgets. But our existing transformer vendor
mucked the design and they saturate at 50 Hz, so we're blowing fuzes
in Europe. These are megabuck systems and our customer is not happy.
Click to expand...
Your own spotty behind was covered by the mention of 50Hz, somewhere
in the spec?

Don't you test these things?

RL
 
John Larkin wrote:

Hi,

Can anybody recommend a good source for a custom torroidal power
transformer? It will be roughly 50 VA; we need prototypes fast, and
maybe 100 per year after that.

There are about 200 suppliers listed in the EEM for torroids, and I
guess we'll spam lots of them with our spec, but I just wondered if
anybody has a vendor they especially like.
Click to expand...
Toroid International.

http://www.toroid.co.uk/

The MD owns the company and is highly knowledgable and most helpful.
Their prices are good too as they manufacture in asia.


Graham
 
I read in sci.electronics.design that John Larkin <jjSNIPlarkin@highTHIS
landPLEASEtechnology.XXX> wrote (in <mu6j01ds31dgvsq8mfa0br3eft55946dbl@
4ax.com>) about 'torroidal transformer vendor', on Tue, 8 Feb 2005:

The CE test involves loading the transformer secondary to just below the
fuse blow point and then waiting to see how hot the transformer gets;
Click to expand...
Which standard are you applying? It sounds to me that you may not be
applying the correct one.
--
Regards, John Woodgate, OOO - Own Opinions Only.
The good news is that nothing is compulsory.
The bad news is that everything is prohibited.
http://www.jmwa.demon.co.uk Also see http://www.isce.org.uk
 
I read in sci.electronics.design that Paul Mathews
<optoeng@pioneernet.net> wrote (in <1107910282.546062.197810@o13g2000cwo
..googlegroups.com>) about 'torroidal transformer vendor', on Tue, 8 Feb
2005:
If you're concerned about turn-on surges, look for an article about new
toroid transformers designed to limit power-on surge:

http://www.powerelectronics.com
Click to expand...
Do you have the title of the article? I couldn't find it on the site.
--
Regards, John Woodgate, OOO - Own Opinions Only.
The good news is that nothing is compulsory.
The bad news is that everything is prohibited.
http://www.jmwa.demon.co.uk Also see http://www.isce.org.uk
 
John Woodgate wrote:

I read in sci.electronics.design that John Larkin <jjSNIPlarkin@highTHIS
landPLEASEtechnology.XXX> wrote (in <mu6j01ds31dgvsq8mfa0br3eft55946dbl@
4ax.com>) about 'torroidal transformer vendor', on Tue, 8 Feb 2005:

The CE test involves loading the transformer secondary to just below the
fuse blow point and then waiting to see how hot the transformer gets;

Which standard are you applying? It sounds to me that you may not be
applying the correct one.
Click to expand...
I think you're right John.


Graham
 
I'm still looking for a better reference, but I've been led to believe
(by a visiting rep) that this toroidal transformer technology, touted
for its EMI filtering benefits, also has improved inrush
characteristics:

http://powerelectronics.com/mag/power_power_transformer_attenuates/

Having just re-read the article, I find no mention there, so apologize
for possibly sending anyone on a goose chase. However, the EMI aspects
are interesting in their own right.
Paul Mathews
 
I did finally find the article I mentioned, April 2004 Power
Electronics Technology, "Solving Inrush Problems at the Source",

http://powerelectronics.com/mag/power_magnetic_solutions_solving/

Paul Mathews
 
I read in sci.electronics.design that Paul Mathews
<optoeng@pioneernet.net> wrote (in <1107977208.169814.26130@g14g2000cwa.
googlegroups.com>) about 'torroidal transformer vendor', on Wed, 9 Feb
2005:
I did finally find the article I mentioned, April 2004 Power
Electronics Technology, "Solving Inrush Problems at the Source",

http://powerelectronics.com/mag/power_magnetic_solutions_solving/

Paul Mathews

I recommend a good deal of caution when considering this paper.
Click to expand...
--
Regards, John Woodgate, OOO - Own Opinions Only.
The good news is that nothing is compulsory.
The bad news is that everything is prohibited.
http://www.jmwa.demon.co.uk Also see http://www.isce.org.uk
 
On Wed, 9 Feb 2005 09:27:44 +0000, John Woodgate
<jmw@jmwa.demon.contraspam.yuk> wrote:

I read in sci.electronics.design that John Larkin <jjSNIPlarkin@highTHIS
landPLEASEtechnology.XXX> wrote (in <mu6j01ds31dgvsq8mfa0br3eft55946dbl@
4ax.com>) about 'torroidal transformer vendor', on Tue, 8 Feb 2005:

The CE test involves loading the transformer secondary to just below the
fuse blow point and then waiting to see how hot the transformer gets;

Which standard are you applying? It sounds to me that you may not be
applying the correct one.
Click to expand...
Apparently it's IEC/EN 61010 2001 Edition, Clause 4.4.2.6.2
and UL 3101, 1993 Edition, Clause 14.7.2

John
 
Paul Mathews wrote:

I did finally find the article I mentioned, April 2004 Power
Electronics Technology, "Solving Inrush Problems at the Source",

http://powerelectronics.com/mag/power_magnetic_solutions_solving/
Click to expand...
Bear in mind that the author's 'specially wound transformers' can be
wound by anyone. It looks like they're simply offering transformers with
a lower than usual working flux.


Graham
 
I read in sci.electronics.design that John Larkin <jjlarkin@highSNIPland
THIStechPLEASEnology.com> wrote (in <3sgl01h9kh5dst54uacb30sk2t3eua2dfm@
4ax.com>) about 'torroidal transformer vendor', on Wed, 9 Feb 2005:
On Wed, 9 Feb 2005 09:27:44 +0000, John Woodgate
jmw@jmwa.demon.contraspam.yuk> wrote:

I read in sci.electronics.design that John Larkin <jjSNIPlarkin@highTHIS
landPLEASEtechnology.XXX> wrote (in <mu6j01ds31dgvsq8mfa0br3eft55946dbl@
4ax.com>) about 'torroidal transformer vendor', on Tue, 8 Feb 2005:

The CE test involves loading the transformer secondary to just below the
fuse blow point and then waiting to see how hot the transformer gets;

Which standard are you applying? It sounds to me that you may not be
applying the correct one.

Apparently it's IEC/EN 61010 2001 Edition, Clause 4.4.2.6.2
and UL 3101, 1993 Edition, Clause 14.7.2

Unfortunately, I don't have either of those standards. Maybe someone
Click to expand...
else can comment. You are sure that the product falls within the scope
of IEC/EN 61010?
--
Regards, John Woodgate, OOO - Own Opinions Only.
The good news is that nothing is compulsory.
The bad news is that everything is prohibited.
http://www.jmwa.demon.co.uk Also see http://www.isce.org.uk
 
John Larkin wrote:

On Fri, 11 Feb 2005 04:54:46 +0000, Pooh Bear
rabbitsfriendsandrelations@hotmail.com> wrote:


John Larkin wrote:

But if the only function of a fuse is to clear shorts, why can't I
just slap in 10 amp fuses and be done with it?

A short on the secondary side will happily draw maybe 5A from the a.c. supply
and the fuse will never blow.

Just try it and see.


No need; I can do the math. More like 50 amps.
Click to expand...
Not with a 50VA toroidal transformer.

Note - *a short on the secondary side*


Graham
 
On Fri, 11 Feb 2005 06:29:53 +0000, Pooh Bear
<rabbitsfriendsandrelations@hotmail.com> wrote:

John Larkin wrote:

On Fri, 11 Feb 2005 04:54:46 +0000, Pooh Bear
rabbitsfriendsandrelations@hotmail.com> wrote:


John Larkin wrote:

But if the only function of a fuse is to clear shorts, why can't I
just slap in 10 amp fuses and be done with it?

A short on the secondary side will happily draw maybe 5A from the a.c. supply
and the fuse will never blow.

Just try it and see.


No need; I can do the math. More like 50 amps.

Not with a 50VA toroidal transformer.

Note - *a short on the secondary side*
Click to expand...
I can *still* do the math!

John
 
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