T-Pain Is On A Boat: Re: [Electric Boats] Magnetic Circuits & The Prototype Motors

Thursday, January 3, 2013

Re: [Electric Boats] Magnetic Circuits & The Prototype Motors

G'day Chris

I would think that spark wire eroding would also be a suitable method of making up a stack of plates for a laminated core, there is no real heat involved to change the material characteristics, and of course the tolerances and part uniformity are as good as stamped parts.

rgds

Alan

----- Original Message -----

From: Chris Morriss

To: electricboats@yahoogroups.com

Sent: Thursday, January 03, 2013 9:05 PM

Subject: Re: [Electric Boats] Magnetic Circuits & The Prototype Motors

In message , Roger L
rogerlov@ix.netcom.com> writes
>
>Yes, I agree. The increasing need for low losses in cores (& way worse
>with high freq. switching) brings up the old problem of eddy currents and
>the traditional solution of using laminated cores to control eddy currents -
>laminations which you quite properly point out are difficult to cut to shape
>in close tolerance in a home workshop. There is also the problem that
>some of the best lamination material loses some of it's goodness when it
>is stressed. Unhappily that happens when high permeability steel is
>impacted, bent, or sheared mechanically. It probably applies to water
>jetting as well, although I have solved that in the past by simply burying
>my head in the sand.....there being no better way to make them.
>

I have been told by colleagues (I design switch-mode PSUs, and Class-D
amplifiers for a living) that water jet cutting is fairly benign on
transformer steel. Avoid laser cutting it seems!

Sadly, dust-iron or ferrite materials can't take the high field strength
of NiFeB magnets (or don't have a high enough permeability), so although
an interesting idea, I'm not sure any type of printed magnetic core
materials are likely to be suitable for these type of motors (not in the
foreseeable future, though I could be wrong...)
--
Chris Morriss

No virus found in this message.
Checked by AVG - www.avg.com
Version: 2013.0.2805 / Virus Database: 2637/5994 - Release Date: 12/28/12