where to source toroid cores?

[walsh350]

Does anyone have any advice on where to get hold of large toroid cores?

Say around 4-6"? 

I want to try some experiments with magnetic fields.

I'm thinking about trying to get hold of something with a soft iron core? Any idea how much that might cost? I need three in total.

Should I just use a plastic toroid?

Suggestions and advice appreciated!

[ElectricGoose]

Youre pretty vague in your requirements so I guess that means youre unsure yourself.

You wont find that size core and certainly not in 'soft iron' unless you make it yourself.

If youre looking to make a big joule thief or anything that wants efficiency you will need a FERRITE CORE with HIGH PERMEABILITY (8000 - 15000 U).  W class ferrites are 10,000 and H class are 15,000 but the H class are becoming rarer and expensive.  J class is OK too and 5000U.

Here is a link and I have pasted the two biggest cores (3 inches OD) they stock)

http://www.cwsbytemark.com/index.php?main_page=index&cPath=206_221



F-290-W /16,280 /2.9 /1.530 inch/0.500 inch/W/10,000/$30.00

F-337-J/5520/3.375/2.187 inch/0.500 inch/J/5000$25.00

[walsh350]

Yeah thanks. I'm just trying to create the strongest mag field possible with the limited resources I have. 

Apparently using a permeable core gives a huge increase in potential magnetic flux strength.

This is a brand new hobby of mine so I'm trying to research and learn as I go. 

[SchubertReijiMaigo]

Ohh... You want to experiment also magnetic field with toroid, maybe Heins effect ? Actually I work (in secret, with my one theory) about this effect...

So, I have several suppliers for this...

European region (my location...)

1) Magnetec: (high petremability "Nanoperm" core ) --> µ=30000, µ=100000 etc... http://www.magnetec.de/magnetec.htm

2) AirlinkTransforemer: core etc... for 50-60 Hz application... (Laminated steel) http://www.airlinktransformers.com/

3) HerosTechnology: "Micrometals cores" for RF, ballast application low permeability cores iron powder/ferrite core µ=10 --> 100,200
http://www.herostechnology.co.uk/pages/pages_comp/micrometals.html

USA/Canada:

1) Toroid Corporation of Maryland: 50-60 Hz Power trafos...
http://www.toroid.com

2) CWS Bytemark: RF, Ballast, low permeability toroid µ=10 --> 100,200 etc
http://www.cwsbytemark.com

3) Surplus sales of Nebraska: Toroid, ferrite, trafos, power trafos, electronics and many things...
http://www.surplussales.com

4) For large volume: Micrometals  http://www.micrometals.com
or Magnetics  http://www.mag-inc.com ...

I know actually only those above, hope it helps...

PS: No advertising or affiliation here, this is just some supplier that I know...

[walsh350]

Thanks for the replies!