Diy AMT - Page 14 - diyAudio
Go Back   Home > Forums > Loudspeakers > Planars & Exotics

Planars & Exotics ESL's, planars, and alternative technologies

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 18th January 2013, 04:59 AM   #131
solhaga is offline solhaga  Sweden
diyAudio Member
 
Join Date: Jun 2009
Location: Värsta Götaland
OB-1: Very interesting.

I did a simulation on something simular. The pole piece, the narrower section, is of course not solid in reality so the field is a little bit weaker and perhaps not so linear top to bottom.

Click the image to open in full size.

Click the image to open in full size.

Click the image to open in full size.

The b.t-field practically zero in the gap.

In a wider gap, the b.n-field breaks up and is not linear over the gap.

The stronger fields at the magnetes are useless because that´s were you probably need to have a supporting structure for the diaphragm anyway.
I´m thinking of having some sort of cassette for the diaphragm that you insert from the top.

Last edited by solhaga; 18th January 2013 at 05:09 AM.
  Reply With Quote
Old 18th January 2013, 07:35 AM   #132
diyAudio Member
 
Join Date: Dec 2011
Thanks for the Beyma link - interesting that they are doing all the mathematical modelling.

I'll probably have no pole piece and just neos right in front of the diaphragm.

On the way home yesterday I noticed a rescue blanket and bought it - 12 um aluminized mylar. One thing that I'm going to try is electroplating it to reduce resistivity and then etching that. I'm hoping to avoid glues.

I checked again and ADAM do say they use purely physical heat pressing of the traces. Maybe this is doable with kapton, but I don't think mylar can handle it.
  Reply With Quote
Old 18th January 2013, 12:21 PM   #133
solhaga is offline solhaga  Sweden
diyAudio Member
 
Join Date: Jun 2009
Location: Värsta Götaland
Quote:
Originally Posted by SEdwards View Post
I'll probably have no pole piece and just neos right in front of the diaphragm.
What size of Neos do you have in mind?
  Reply With Quote
Old 18th January 2013, 01:00 PM   #134
diyAudio Member
 
Join Date: Dec 2011
I think that the 30 mm ones look about right and they aren't so expensive. I'm buying some as a prize when I hand in my dissertation. I don't want to go wider than 1 inch for the exposed part of my diaphragm.

It seems that plating onto Alu is difficult - I guess that I will glue instead. Need a nice choice for glue though, that's cheaper than buying kapton tape. I saw 50 mm kapton tape for about 6 EUR on ebay. I'll buy it sooner or later I guess, but first I'll try with the 12 mylar.
  Reply With Quote
Old 18th January 2013, 02:31 PM   #135
solhaga is offline solhaga  Sweden
diyAudio Member
 
Join Date: Jun 2009
Location: Värsta Götaland
So you will have Neos and gaps interlaced? Could you provide a simple sketch?
40x5x5 Neos would be super, having them with 10 mm gaps inbetween.

I´ve used 3M's Spray Mount or Scotch 77 spray for gluing alu-strips on mylar that still holds after two years of heavy use.
  Reply With Quote
Old 18th January 2013, 02:34 PM   #136
diyAudio Member
 
Join Date: Dec 2008
[IMG]Click the image to open in full size.[/IMG]
Dont use iron at the ends´,it shortens magn.field.
[IMG]Click the image to open in full size.[/IMG]
[IMG]Click the image to open in full size.[/IMG]

This is made with 5x10 neodymn. 5mm.gap.Iron 2,5mm.Might be 4mm. with holes.

Bernt
  Reply With Quote
Old 18th January 2013, 02:46 PM   #137
solhaga is offline solhaga  Sweden
diyAudio Member
 
Join Date: Jun 2009
Location: Värsta Götaland
Yes, you are right. I did simulation for such a configuration but didn´t have avy pics to upload.

Having Neos as "pole pieces" doesn´t seem to a good configuration though.
  Reply With Quote
Old 20th January 2013, 07:32 AM   #138
diyAudio Member
 
Join Date: Dec 2011
Sorry, but I'm too busy chasing a deadline to sketch something up - I'm imagining something very simple though, just planks of neos across the front with pole pieces only if I really need them.

Will be building as soon as my studies are done.
  Reply With Quote
Old 20th January 2013, 09:31 AM   #139
diyAudio Member
 
Join Date: Dec 2008
Hi SEdwards

Here is a tread showing a diy amt "motor".There are measurements too.
http://www.avsforum.com/t/1364670/an...or-larger-amts

Bernt

Last edited by båndsei; 20th January 2013 at 09:32 AM. Reason: Forgot link
  Reply With Quote
Old 20th January 2013, 09:49 AM   #140
solhaga is offline solhaga  Sweden
diyAudio Member
 
Join Date: Jun 2009
Location: Värsta Götaland
So the size of the Neos are 5x5x40 or what?
Do you know where to purchase them?
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
AMT diaphragm DIY basics. graeme uk Planars & Exotics 2 9th December 2010 09:17 PM
DIY AMT: which of the three replacement diaphragms to use? capslock Planars & Exotics 3 4th July 2010 05:26 PM
big AMT Diy Charcoal Planars & Exotics 27 13th October 2008 06:41 AM
Diy Amt ? woody Planars & Exotics 0 24th September 2005 11:17 AM
Diy Amt JohnL Planars & Exotics 4 29th April 2005 03:16 PM


New To Site? Need Help?

All times are GMT. The time now is 12:36 AM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright ©1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2