40782
From: Steven, [199.73.1.1]
Subject: Stationary voicecoil?
|
I would like to preface this by stating that I am not an an engineer or science professional so I apologize if there are obvious limitations I am missing. With that said, here is my dilemna. I am looking to construct a subwoofer using a stationary coil and moving magnet. To achieve this I would be using a large coil with a very tiny permanent magnet shaft running through the interior of the coil which attatches to an unconventional diaphram. With my current design I am not having issues with the diaphram staying linear but I am currently working with a very small prototype. The excursion on a full scale model will be approximately 5 inches. What materials might I be able to use as suspension? What are my options as far as methods of keeping such a device linear? Would the magnetic force of the coil keep the magnetic shaft in the center linear? Any advice would be appreciated. Steven |
40796
From: Peter Schumacher, [hqfirepu1-ext.agedwards.com]
Subject: Re: Stationary voicecoil?
| Supercool the voicecoil (liquid nitrogen) to avoid magnet heating, and use clockwork springs for the suspension as Sumit suggested. |
Responses:
None
40789
From: sumit, [barco-34-152-16-del.barco.com]
Subject: Re: Stationary voicecoil?
|
If u are aware of old wall clocks ,they have a circular converging metal spring which can be used for the suspention .I used four, years ago for a very diff. application. My shaft moved about + - 4". cheers |
Responses:
None
40787
From: djk, [tc111.cedar-rapids.net]
Subject: Re: Stationary voicecoil?
|
Even if the magnet had no mass the flux would be modulated by the voice coil and the heat would de-pole the magnet. It will work as a low force linear actuator. |
Responses:
None
40784
From: Bill Fitzmaurice, [pool-70-20-59-85.man.east.verizon.net]
Subject: Re: Stationary voicecoil?
| The mms of a moving magnet versus moving coil would likely end up with an unusably low sensitivity,even with neodymium magnets. A small enough magnet to keep the mms reasonable would have too low a bl product as a result. 5 inch excursion is the domain of servodrivers, not dynamic drivers. If that's your goal a servodriver is the way to do it. |
Responses:
None
40783
From: van, [helpdesk02.helpdesk.uidaho.edu]
Subject: Re: Stationary voicecoil?
| I would worry that the magnet would be heavy thus being sloppy... But kind of a cool idea dude, keep us posted on how it works out. |
Responses:
None
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