Self-centering Magnetic Suspension?

[kelticwizard]

Originally Posted by Jef Nuyts

To compensate the powerhandling of alu windings also damping and centering i thought ferrofluid can achieve all these.

Here is the US patent number for a spiderless, ferrofluid woofer used in Bogen utility speakers and manufactured by NEAR, which was, (still is?) a very reputable loudspeaker system manufacturer known for fine home loudspeakers.

US005335287

Just go to United States Patent and Trademark Office and see the patent.

Please do keep us posted, this is very interesting.

PS: Apparently Bogen and NEAR are now one and ferrofluid woofers are now used on selected Bogen speakers below. I don't think they are too expensive. Here's their web page. The woofer on the professional 12" and 15" does not have the ferrofluid, but several other models do.

http://www.bogen.com/products/NEARspeakers/

[bear]

afaik Jordan modules do not or did not use a spider.

[Jef Nuyts]

Sorry but I can't find the patent listed above US005335287. I have searching the entire site on spiderless but can't find it. Do I oversee something?
Maybe next week I gonna test the new setup. If it is not what i hoped for I wil post also the drawing on how I made the EM suspension. For now it is classified ;-)
Some DIY'rs already tried to make EM-suspension with a coile above and beneath the magnetic gap but this is not near lineair on the "zero" spot (almost undo-able) because the magnetic field don't stop at the end of the gap it fade out. There is a better yet simple and cost effective solution. I search the internet for months if someone has also the same solution to this but for now nobody found (yet). I will post a youtube video for you guys to see it in action...

[planet10]

US5335287 yeilds a patent in the name of Aura.

dave

[kelticwizard]

Jef:

Sorry for sending you on the search. This referral to patents thing is more complicated than I thought. Turns out that US00.... number is not the form the patent website likes. This should get you there.

Method 1:
Please go here-this will bring you to the patent and drawings.
United States Patent: 5335287

Method 2:
This should bring you to the patent search page:
US Patent Full-Text Database Boolean Search

Copy this number and fill it in on the Term 1 search box:
5,335,287

There will be several choices, look for this title:
Loudspeaker utilizing magnetic liquid suspension of the voice coil

Method 3:
www.uspto.gov
patents, (written in white in blue-green box)
Search Patents, (box in bottom third of page)
Quick Search, (might have to scroll down to see it)

Copy this number and fill it in on the Term 1 search box:
5,335,287

There will be several choices, look for this title:
Loudspeaker utilizing magnetic liquid suspension of the voice coil

Best of luck on this fascinating project and we look forward to you keeping us posted!

[kelticwizard]

PS:
I don't know if you still have to use this on Windows, but if you can't get any images you might have to download Alternatiff.
AlternaTIFF - Free TIFF Plug-in

[Jef Nuyts]

Originally Posted by kelticwizard

Jef:

Sorry for sending you on the search. This referral to patents thing is more complicated than I thought. Turns out that US00.... number is not the form the patent website likes. This should get you there.

Method 1:
Please go here-this will bring you to the patent and drawings.
United States Patent: 5335287

Method 2:
This should bring you to the patent search page:
US Patent Full-Text Database Boolean Search

Copy this number and fill it in on the Term 1 search box:
5,335,287

There will be several choices, look for this title:
Loudspeaker utilizing magnetic liquid suspension of the voice coil

Method 3:
www.uspto.gov
patents, (written in white in blue-green box)
Search Patents, (box in bottom third of page)
Quick Search, (might have to scroll down to see it)

Copy this number and fill it in on the Term 1 search box:
5,335,287

There will be several choices, look for this title:
Loudspeaker utilizing magnetic liquid suspension of the voice coil

Best of luck on this fascinating project and we look forward to you keeping us posted!

Thanks for helping me out. I have found the correct patent. The fluid is on it's way 4 days remaining. Maybe this weekend I can give you the first results... For me, it is a extra stimulant to continue with this project if there are people who are actually intrested in my work. So thx and see you soon...

[scott wurcer]

Originally Posted by jcx

diamagnetic interaction can apparently enable stable "passive" magnetic suspension:

http://www.mae.ncsu.edu/courses/Mae5...Levitation.htm

(from American Scientist online, search: diamagnetic levitation

American Scientist Online

in case they pull the classroom link to the article)

You can put together a demo with bismuth plates as the diamagnetic material a neat experiment but VERY touchy the diamagnetic effect is orders of magnitude less than the magnetic one.

[tomtt]

another -

Patent EP1819194B1 - Ferrofluid centered voice coil speaker - Google Patents

[jcx]

my post' links dead - Diamagnetic Levitation seems to work