transformer theory returns

[gav]

hello again,
I've been doing a bit of reading and think I'm ready to try winding my own
transformer.
Anyone got a burnt out toriodal that I can pick up from somewhere in
melbourne?

My gf won't let me spend too much money on this sort of rot.

thanks,
gavin

 

[Rob Judd]

Gav,

Truscotts in Croydon have a selection of toroid cores, some are wound as
filter chokes and could be easily modified. Cheap.

Rob

 

[gav]

Gav,

Truscotts in Croydon have a selection of toroid cores, some are wound as
filter chokes and could be easily modified. Cheap.

Rob

Thanks. I have their address and will check it out.
gavin

 

[gav]

Gav,

Truscotts in Croydon have a selection of toroid cores, some are wound as
filter chokes and could be easily modified. Cheap.

Am really looking to draw some power for this experiment. Need something
around 150-300VA if possible.
Are toroidals silicon steel like EI types?

gavin

 

[Phil Allison]

Am really looking to draw some power for this experiment. Need something
around 150-300VA if possible.
Are toroidals silicon steel like EI types?

** Gav - you are a bit weak on terminology. A "toroidal core " is any
core of that shape, a "toroidal transformer core" is the same as above.
What you need is called a "wound GOSS strip transformer core".

GOSS stands for "Grain - Oriented - Silicon - Steel"

These cores are made for use in AC supply transformers and sometimes
audio transformers - a single long strip of thin ( insulation coated)
steel is wound to form a core that is shaped like a section of a cylinder.
Plastic covers are then fitted so that enamelled copper wire can be safely
wound around the core.

When fully covered in wire the shape suggests a toroid - or a round
cross section ring.




.......... Phil

 

[Vermin]

hello again,
I've been doing a bit of reading and think I'm ready to try winding my own
transformer.
Anyone got a burnt out toriodal that I can pick up from somewhere in
melbourne?

My gf won't let me spend too much money on this sort of rot.

thanks,
gavin

Cool.

Now look into the theory of massive amounts of RF power through
loosely coupled tuned transformers like this;

http://www.richieburnett.co.uk/tesla.shtml

Then see what yer missus says.

 

[gav]

** Gav - you are a bit weak on terminology. A "toroidal core " is any
core of that shape, a "toroidal transformer core" is the same as above.
What you need is called a "wound GOSS strip transformer core".

GOSS stands for "Grain - Oriented - Silicon - Steel"

These cores are made for use in AC supply transformers and sometimes
audio transformers - a single long strip of thin ( insulation coated)
steel is wound to form a core that is shaped like a section of a cylinder.
Plastic covers are then fitted so that enamelled copper wire can be safely
wound around the core.

When fully covered in wire the shape suggests a toroid - or a round
cross section ring.

Ahh, thanks.
The guy I asked in an electronics store said.. "There yellow, Like this..."
So any Mains Supply transformer will be GOSS type.

Thanks.
gavin

 

[Mark Harriss]

Ahh, thanks.
The guy I asked in an electronics store said.. "There yellow, Like
this..." So any Mains Supply transformer will be GOSS type.

Goss is plain old tranny silicon steel which has the grain
structure aligned in one direction by rolling it in one direction during
manufacture. Even in a conventional E-I tranny, the grain is aligned to the
magnetic field for the three vertical legs but runs at right angles for the
top and bottom parts of the transformer. Only in a c-core or a toroid does
the mag field and the metal grain align all the time. This allows a higher
flux density before the material magnetically saturates so you can then use
less steel to make a transformer of a give VA rating. All GOSS allows you to
do is make a smaller more efficient transformer with less iron losses.

 

[Phil Allison]

Goss is plain old tranny silicon steel which has the grain
structure aligned in one direction by rolling it in one direction during
manufacture.

** Not so.

GOSS is high grade transformer steel and the kind used for toroidal
cores is better than E-cores use. No E-core tranny made has the
extraordinary low magnetising current of all toroidals or good C-cores.

Even in a conventional E-I tranny, the grain is aligned to the
magnetic field for the three vertical legs but runs at right angles for the
top and bottom parts of the transformer.

** Not so.

It runs along the "I" piece in the oriented direction ALSO.

Only in a c-core or a toroid does the mag field and the metal grain align

all the time. This allows a higher

flux density before the material magnetically saturates so you can then use
less steel to make a transformer of a give VA rating.

** C core and toroidal cores have little or NO air gaps included - this
is the real secret of low I-mag.




............ Phil

 

[Mark Harriss]

** Not so.

GOSS is high grade transformer steel and the kind used for toroidal
cores is better than E-cores use. No E-core tranny made has the
extraordinary low magnetising current of all toroidals or good C-cores.

From the Acesita website:

http://www.acesita.com.br/eng/interno.php?area=faq_silicio


Q: What is the main difference between the grain oriented (GO) and the grain
non-oriented (GNO) silicon steels?


A: The main difference between the GO and GNO steels is in their crystal
strucuture. GO silicon steel has a texture called Goss, in which the
crystals are arranged in the direction of the easiest magnetization
(direção [001] - cube's adge), parallel to the rolling direction and to the
cube's diagonal plan (110) and parallel to the plate's plan. This kind of
structure turns the GO steel into a material with excellent magnetic
characteristics in the rolling direction and makes it suitable to the use
in static cores where the magnetic flow is similar to the rolling
direction, such as the transformers. GNO steel doesn't have a texture and
it shows similar magnetic characteristics in all directions. This makes it
siutable to the use in machines where magnetic flow is constant changing,
such as electrical motors and power generators.

** Not so.

It runs along the "I" piece in the oriented direction ALSO.

Yep thats true but it still runs at 90 degrees to the grain for
about 30% of the magnetic circuit which makes it not as good as toriodals.

** C core and toroidal cores have little or NO air gaps included -
this
is the real secret of low I-mag.

What steel E-I mains power transformers have airgaps Phil?, Maybe
in something with a DC current like a class A audio output transformer.

 

[Phil Allison]

From the Acesita website:

** Mark, you a such a ***fucking idiot*** you cannot even figure out
what the point is.

Go test a toroidal and you will maybe learn something.

Until you have - go masturbate yourself privately.





............ Phil

 

[gav]

Thankyou mark and phil.
The link was helpfull
thankyou
gavin.

 

[Rob Judd]

Toroidals are a single molded construction, so nothing like E-I at all.
The ones I saw were low frequency types, probably powdered iron
material. At a guess they would handle your requirement.

Rob

 

[Phil Allison]

Toroidals are a single molded construction, so nothing like E-I at all.

** Ones for AC supply and audio are nothing of the sort.

The ones I saw were low frequency types,

** Ambiguous, stupid and mindless.

The OP needs 50 Hz capability - not 50kHz.



................ Phil

 

[Mark Harriss]

Quite obviously Phil you should be taking this
problem up with the manufacturers of silicon steel as
their explanation agrees with mine and not yours
Truthful Phil.

 

[Mark Harriss]

Thankyou mark and phil.
The link was helpfull
thankyou
gavin.

No problems Gav, Some of the guys
at rec.audio.tubes would also be able to
supply some transformer theory too, but
make sure you put "off thread" in the title.

Mark Harriss

 

[Phil Allison]

Quite obviously Phil you should be taking this
problem up with the manufacturers of silicon steel as
their explanation agrees with mine and not yours

** You are the one with a problem.

You are still masturbating in public.






.............. Phil

 

[Mark Harriss]

OOOHH! OOOH!!! I am so cut down by your highly technical
disputation of my assertions about the grain in GOSS being
oriented along the axis of rolling. If I wasn't laughing
so much I'd be inclined to compare you to a penis breathed
felcher, Truthful Phil.

 

[Phil Allison]

OOOHH! OOOH!!! I am so cut down by your highly technical
disputation of my assertions about the grain in GOSS being
oriented along the axis of rolling.

** Are you on drugs, Mark ?

Cos you are posting utter nonsense.

Maybe you NEED some drugs and have not taken them.

ADHD does need constant treatment.




............. Phil

 

[Mark Harriss]

Nah this is just a game for you where you try for the last post
each time....I'll have to look up the Phil Allison FAQ to see which
method number this is.