Transformer' Air Gap

"Depending on application, air gap may be filled with a non-magnetic material such as gas, water, vacuum, plastic, wood etc. and not necessarily just with air.^3)4)"

^{Barring any specific specialised requirements, I would go with air.....}

^{http://www.encyclopedia-magnetica.com/doku.php/air_gap}

Well - Actually I need non-magnetic material , specially for filling the magnetic core air gap, with the exact thickness : 1/16 ".

It will face high tight pressure , but without changing its thickness..

Well then, you've answered the question.

You'll have to use high pressure air.

Then I would go with carbon fiber...

I vote for a thixotropic epoxy.

I need information from true experienced transformer / inductor builder !

Though I know that all those experts moved now to India and china.

Thanks for your guessing .

Then go to true experienced transformer / inductor builder and ask them for help.

You get what this forum has to offer. If you don't like it we can't help that!

You might try doing your own search for information too, if you don't like ours!

Magnetics Designer: Transformer and Inductor Design and Analysis ...

Power Transformer & Inductor Design

Dude, when you give so little precious information, how in the world are we to guess your requirements? Nothing about operating temperature, acoustic requirements, dry or wet transformer, power levels, voltages, mechanical requirements, nothing. Ask a stupid question, you'll GET a stupid answer. Have a nice day.

Is this a trick question?

No - not a trick question.

But only persons working in that field can answer my question.

It is career question.

Then find, "persons working in that field" and ask them to educate you.

Or, go to the sites that I listed and do your own work!

I used to work in the field a lot. Strawberries and sunflowers were the worst.

No, it won't do anything for him because he has no clue.

And, some grades of "stainless steel" are magnetic.

In the end, this will be the result at commissioning:

If you put any of those in an air gap, then it ceases to be an air gap!

What rot.

Sneak up on their factory with a drone and take detailed wide spectrum photographs of the waste materials they throw away that are 1/16" of an inch thick, maybe you get lucky. I would just use a rigid material such as a high impact resistant, high modulus plastic, then remove it afterward if need be, if possible.

What do other transformers of this class appear to use throughout?

Other manufacturers may unintentionally reveal the construction of their transformers in their product literature, as another means of having their information as a starting point to reverse engineer from, then forward engineer it, or you will end up forward enginerring it by yourself.

Thanks for reply and advise.

Actually such type of manufacturer never release any technical secrets - even inside the one company with different departments.

Every department unaware about the other department' technical secrets.

The answer is in the question, Mildred. If it is an air gap, then I really wouldn't expect it to be filled with strawberry jam instead.

We used fibreboard for isolating the limbs of inductors

1.5mm thick Mica shim would almost be thick enough. Maybe where you are, there would be 1/16" Mica shim available.

My Australian metric items would probably be less suitable than all the previous suggestions.

Further information:

Temperature : 200 degree C

Air gap cross sectional area : 2 1/4 " X 2 1/2 "

Air gap thickness : 1/16 "

Oh, what a tease..... It is career question. Whose? Yours or someone elses?

First, if you stick anything in the gap, then it changes the properties of the gap.

200 degrees C? Have you considered the expansion over the temperature range? What kind of insulation are you using? What kind of power rating are you talking about?

Please send pictures of the finished product, before closing the lid and at commissioning.

Be advised that you may need an explosion proof camera.

Well lyn- I do not know why you always in argument with my question and comments ?

Always trouble maker !

No, reality checker.

Your posts are outlandish.

I gave you references to help you design your transformer and you ridicule me?

ridicule me ?

How come ? I did not even reply to your comment ??

Your reference is not more than software with tables to fill it - with no any technical information --- Just calculator !!

What we have, is failure to communicate.

"I did not even reply to your comment ??"

Good luck.

At 200deg C he is already cooking the insulation off his windings! At 2 1/4" x 2 1/2" He's probably messing around with a MOT in his garage! Maybe we'll get lucky and not hear from him again for a while...

You may have to explain the usage and meaning of the term MOT, in the context of your post. I can make neither heads, mutts, nor tails of it...

Microwave Oven Transformer

Quite. MoT here is the annual safety inspection for >3 year old vehicles to be used on public roads.

Gaps in a magnetic circuit change the reluctance of the circuit just like a resistor changes the resistance of an electric circuit. And just like an electric circuit where the resistance is chosen to fulfill a particular requirement, so too is the gap material chosen to alter the magnetic flux that passes through the gap.

You have told us nothing about your purpose for even asking the question, but have received some nuggets of information that might guide you; however playing "twenty questions" here will only get you many more questionable responses. If you don't ask a qualified engineering question don't expect a qualified engineering response.

MY QUESTION IS VERY SIMPLE AND CLEAR :

What material is used to fill the air gap of magnetic core ??

such insulating material must be of thickness 1/16 " and good for temperature up to 200 degree C.

If you you do not have the practical experience on that , please do not answer , or tell excuses....

I am quit clear !

When my graduate electrical power engineering students cut an attitude like that they were told that their grade was now a "D" and that it could only revert if they improved the quality of their query in both content and tone.

As others have said, once you have filled the "air" gap with something other than "air" it no longer is an "air" gap, instead it is now a gapped-core transformer, and the characteristics depend upon the magnetic properties of the material in the "gap". Now go do your own homework. This is not a homework cheat site.

I have many years of both, but will defer to your final words. <unsubscribes>

At that temperature, your choices should become very narrow, mica might be one. There might be some glass-filled epoxies that could also work.

Question: isn't this just a little bit out of the ordinary to have such a high temperature?

Is this equipment going to Venus? A volcano? Geothermal in Iceland?

Class H transformers are very common in industry.

NEMA specifications for Class H insulation is for 200 degree C. operation.

IF IT'S AN AIR GAP THEN IT WOULDN'T HAVE ANYTHING ELSE IN IT.

Verdammt.

I do not know where lyn and his brother Tornado runaway from this ?

Since you are new here this is your one polite freebee you get from me even though you're being an ass.

First off I already gave you a list of materials of which many that will fit your thermal and magnetic property characteristics.

Ceramic begin near invisible to common magnetic fields plus has high temperature and physical compression load properties. So would common stone like marble or granite. So would a number of epoxies and even certain plastics and composite materials. Same with common fireplace grout.

As for everyone else's posts what exactly do you want from all of us?

You gave us your criteria (1/16" thick, non compressible, magnetic properties of air, and thermally stable at 200 degrees C) and several more than suitable materials have been mentioned yet you appear to have zero capacity to understand what it is that is being said to you.

As for transformer manufactuueres materails being proprietory BULLSHYTE. Buy one, disassemble it, identify the materials used and find a supplier.

Do you need data sheet and part numbers for materials or what? Because as has been said so far numerous materials have been suggested.

" disassemble it, identify the materials used and find a supplier " !!!!

Can you identify a material on your hand - when its manufacturer is the only person who knows its composites ?? .

Speak technically please - it is not a vegetables' market , and Tomato plant on your hand.

Try me. You have no idea what me or most people here can identify by look feel and a few basic tests.

Transformer steel or ferrite power. Standard material anyone can buy it in any volume they want.

Enamelled copper/aluminum or copper clad aluminum wire/sheeting. Anyone can buy any grade or custom size and type the want.

Bobbins. Mass produced or custom sized out of a number of materials like plastic, composite or wood based materials anyone can buy.

Shims. Wood, wood composites, full composites, or plastics anyone can get a hold of.

Insulation. Common off the shelf items most any paper supply place has or can get.

The rest is just glue, resins or adhesives of which all are not difficult to identify by basic physical and or chemical analysis and internet searches.

That's all there is to make any transformer or solenoid that can be found on the market. Even specialty custom applications.

Prove us wrong by specifying what you are working on. I'll put my money on someone here knowing exactly what you are trying to do and how you're failing to achieve it!

(Not that I or anyone else expects you actually will.)

Olie: A small word of advice, don't agitate the folks you are attempting to get to help you.

As to transformers, I defer you to your own devices. (unsubscribes)

Well - I mentioned before , If you are not working in that career and have the practical experience , do not get involved and do not try to answer my question

Olie,

You, obviously do not possess enough intelligence to select your own "air" gap material, and are incapable of performing the most basic research needed to determine a suitable filler material from the internet, although there are numerous sources that even my 10 year old could find in 5 minutes.

RUDENESS and ARROGANCE will never replace knowledge, nor serve you well on this forum, as anyone of average intelligence would have concluded long ago.

Unfortunately, your meager level of sophistication, and lack manners, leaves you devoid of any hope for ever succeeding in the technical world, or on this forum.

You should offer humble apologies to the members and fade into the night, never to be heard from again!

@ lyn, what you said is a bullshit... You have no answer to my question.

Announce your technical bankruptcy please.

lyn... I did not hear from your older brother Tornado !

Where he is ??

What are the odd it's really my troll with a name this time around?

Same rude child like BS runaround and personality I am way too familiar with.

He's an 'expert' and everyone else's is not even if he can't make sense of his own stupidity in his questions.

Well- lyn will vote you for good answer now.

Olie...

1. Forty five years ago, my company changed from inches to millimetres for all new design - it was a national plan. Why are you still using inches?
2. Your first post never said it was vital to have your required gap and that was the reason for filling with solid material. Obviously, that would exclude gases and liquids. You did not bother to give the temperature. Paper has been used up to 100 Celsius since transformers became common.
3. If it is any kind of normal transformer the gap will change its dimensions between cold and 200 Celsius and due to magneto-striction. Stopping that will require a considerable force/pressure on the insulation. When you have that pressure and how long the gap must be held at what tolerance and temperature you will be in a position to go to a material supplier - Google "buy Class H solid electrical insulation". Do not forget to specify all the materials which might get in contact with this insulation, humidity affects many materials.
4. Why do you want an exact air gap?

Thanks for reply.

Actually I am making a linear steal reactor with gap 1/16 " - or 15-16 mm.

The design is class H insulation ( 200 degree C.)

What material can be used to fill such gap ??

Thanks for help

Correction .....1/16" = 1.59 mm

Diamond

Yes ,I mean 1.5 - 1.6 mm

But that is not the issue.

What is the material to be used for filling ( adjusting) the 1/16 " inch gap ??

I want a person working in that career to answer my question !!

No guessing.

http://www.glastic.com/en/products/glastic-electrical-products/flat-sheet-laminate.html

View Grade FHT SG200 brochure

Amazing what a search in Engineering 360 can find....Products & suppliers → Dupont → Nomex → Distributers → www.electro-wind.com → Dry Type transformers → rigid insulating sheet → web search, Rochling Glastic .