Re: [CAD_CAM_EDM_DRO] Re: 3-phase variable reluctance motors

To: CAD_CAM_EDM_DRO@yahoogroups.com
From: "dex367" <dexlabboy@...>
Date sent: Fri, 12 Mar 2004 14:36:54 -0000
Subject: [CAD_CAM_EDM_DRO] Re: 3-phase variable
reluctance motors
Send reply to: CAD_CAM_EDM_DRO@yahoogroups.com


I have a couple of these motors, not sure of ratings, but are about $
inches in dia and 6-7 inches long. Mine came on a Sub assembly
that has a capacitor and resistor in series hooked across two black
leads and 110 volts single phase across the black and white lead.

If I can be of help, I will dig them out and answer any questions
I can.

<My memory is that they are rated (nameplate) at 72 rpm.
I am at
bobmcknight@...
and am in Phoenix Az

[ Double-click this line for list subscription options ]

--- In CAD_CAM_EDM_DRO@yahoogroups.com, Thomas Fritz
<tomfritz@d...>
wrote: > I've got my little grubby hands on a few of these, and I was
wondering > what they might be used for. > > The rundown: > Superior
Electric Slo-Syn stepper/synchronous motor > 65 oz-in holding torque

>

24 step/rev > 36V operation, 2.5A > > These things have 4 wires...one
is common, the other 3 go to the coils. > > What gets me is that the
shaft is so free-spinning, not at all like the > steppers I'm used to.

I have done a lot of work with variable reluctance / switched
reluctance motors.

In a nutshell they have only a stack of metal laminations for the
rotor. The magnetic field of the rotor will pull the pole of
lamination like a electromagnet picking up nails (Remember doing that
as a kid?). Because there is no magnets in the rotor there is no
clogging torque.

Here is the kicker. These motors are very unstable if you look at
them mathamatically. That is there strengh and weakness. The
strengh
is because they are so unstable they can be ran a wide speed range,
from couple for RPMs to 15K RPM with an amazing ramp speed. The
weakness is you need a bit of processing power to control the
commutations. I have used a DSP with success. You can run them
with
a stepper driver but you will have alot of torque ripple.

Dex



Addresses:
FAQ: http://www.ktmarketing.com/faq.html
FILES: http://groups.yahoo.com/group/CAD_CAM_EDM_DRO/files/
Post Messages: CAD_CAM_EDM_DRO@yahoogroups.com

Subscribe: CAD_CAM_EDM_DRO-subscribe@yahoogroups.com
Unsubscribe: CAD_CAM_EDM_DRO-unsubscribe@yahoogroups.com
List owner: CAD_CAM_EDM_DRO-owner@yahoogroups.com,
wanliker@...,
timg@... Moderator: pentam@...
indigo_red@... davemucha@... [Moderators] URL to
this
group: http://groups.yahoo.com/group/CAD_CAM_EDM_DRO

OFF Topic POSTS: General Machining
If you wish to post on unlimited OT subjects goto:
aol://5863:126/rec.crafts.metalworking or go thru Google.com to reach
it if you have trouble. http://www.metalworking.com/news_servers.html

http://groups.yahoo.com/group/jobshophomeshop I consider this to be
a sister site to the CCED group, as many of the same members are
there, for OT subjects, that are not allowed on the CCED list.

NOTICE: ALL POSTINGS TO THIS GROUP BECOME PUBLIC
DOMAIN BY POSTING
THEM. DON'T POST IF YOU CAN NOT ACCEPT THIS.....NO
EXCEPTIONS........
bill List Mom List Owner


Yahoo! Groups Links