[SOC] Re: [E-Q&A] Torgue strain gauge
Paul Bartlett
[email protected]
Fri, 14 Mar 2003 21:38:08 -0000
Hmmm,
I studied physics at Imperial College, London in the late seventies. I
suspect the fundemental laws haven't changed too much in the interim.
I respectfully withdraw from the thread.
I'll be watching with interest though ;-)
Paul :-)
----- Original Message -----
From: "Gerry Sorensen" <[email protected]>
To: <[email protected]>
Sent: Friday, March 14, 2003 9:28 PM
Subject: RE: [E-Q&A] Torgue strain gauge
> Paul,
> There is a gentleman named Bill Muller
> http://www.theverylastpageoftheinternet.com/menu/muller.htm
> who has invented a Magnet based generator/motor. He is claiming overunity
> operation. Two unusual claims are because of the arrangement of magnets
and
> coils he has eliminated drag. The second claim is, and he has a patent
here,
> (although a patent doesn't always mean it works) that by using a black
sand
> (amorphous material)
>
http://www.theverylastpageoftheinternet.com/research/replicate/blacksand.htm
> hysteresis losses are minimized the claim is that this yields maximum
> induction with little drag.
>
> What I've been able to determine is he hasn't worked well with anyone
trying
> to validate his claims. I'm in communication with his daughter trying to
get
> information and questions answered.
>
> I've been around long enough to hopefully remain objective; however, I've
> also seen a number of scams. I think I'm approaching this with the right
> frame of mind.
>
> Gerry
>
>
>
> -----Original Message-----
> From: Paul Bartlett [mailto:[email protected]]
> Sent: Friday, March 14, 2003 2:31 PM
> To: [email protected]
> Subject: Re: [E-Q&A] Torgue strain gauge
>
> Gerry,
>
> You may well have covered this already in previous posts (and if so, I
> apologise) but just to satisfy my curiosity, exactly what is it that
you're
> trying to measure?
>
> Best,
>
> Paul :-)
>
> ----- Original Message -----
> From: "Gerry Sorensen" <[email protected]>
> To: <[email protected]>
> Sent: Friday, March 14, 2003 8:29 PM
> Subject: RE: [E-Q&A] Torgue strain gauge
>
>
> > I'm new to this system and as I said my background is Digital and
> > instrumentation and magnetic induction a weakness...but yes I've thought
> > that this would be possible. And from that the force could be
calculated.
> > However at the moment the person who has the test set up is in Canada. I
> > don't have the flywheel as of yet.
> >
> > If I remember correctly from Physics 201 (long ago)...as the magnetic
> field
> > cuts the coil I'll get a pulse and as it leaves the coil an equal an
> > opposite pulse is generated. The thing I'm not sure of is... I know this
> is
> > the case with a square coil (loop) but is this true with a circular coil
> as
> > well?
> >
> > Obviously, the voltage spike from the coil would be much more defined
and
> > consistent. But I haven't had the pleasure of witnessing the phenomena
> with
> > a scope. If I were able to It would probably all be moot.
> > Gerry
> >
> >
> > -----Original Message-----
> > From: Paul Bartlett [mailto:[email protected]]
> > Sent: Friday, March 14, 2003 2:03 PM
> > To: [email protected]
> > Subject: Re: [E-Q&A] Torgue strain gauge
> >
> > Gerry,
> >
> > Is there any reason why you shouldn't measure the perturbation in the
> > current in the pick-up coil as the magnet flies past? If there's
> sufficient
> > interaction between coil and magnet to load the motor then seeing that
> > on the coil should be peasy. Or have I missed the point...?
> >
> > Best
> >
> > P
> > ----- Original Message -----
> > From: "Gerry Sorensen" <[email protected]>
> > To: <[email protected]>
> > Sent: Friday, March 14, 2003 7:22 PM
> > Subject: RE: [E-Q&A] Torgue strain gauge
> >
> >
> > > Paul,
> > > At this time I don't have a picture. I'm preparing to set the system
up
> to
> > > do the test. If I monitor the current or use the decoder wheel then I
> > could
> > > hook the motor directly to the flywheel. The flywheel has a circular
NEO
> > > magnet imbedded and a stationary pickup coil, with core, positioned
> 0.010
> > > away from the magnet. As the magnet moves under the coil it produces a
> > > cogging effect. It's this drag pulse that I'm trying to determine.
> > >
> > > The thinking is that if you place an even number of magnets on the
> > flywheel
> > > and an odd number of stationary coils then the drag will cancel
> depending
> > on
> > > the placement i.e., one moves under and another is moving away at the
> same
> > > time.
> > >
> > > My problem here is I don't have a clear understanding as of yet of
> > magnetic
> > > induction.
> > >
> > > I would think that the increase in current do to the drag pulse would
be
> > > quite fast in comparison to the slow speed change of the motor.
> > > Gerry
> > >
> > > -----Original Message-----
> > > From: Paul Bartlett [mailto:[email protected]]
> > > Sent: Friday, March 14, 2003 12:53 PM
> > > To: [email protected]
> > > Subject: Re: [E-Q&A] Torgue strain gauge
> > >
> > > Hi Gerry,
> > >
> > > I'm still a little unclear as to the mechanical arrangement.
Monitoring
> > > motor current does indeed give an indication of the torque being
> delivered
> > > by the motor into its load, but without a suitable feedback loop
> > (attempting
> > > to maintain constant speed, say), little or no information can be
> gleaned
> > > from it alone since it's an input to the system rather than an output.
> > >
> > > Do you have a picture available?
> > >
> > > Best,
> > >
> > > Paul :-)
> > >
> > > ----- Original Message -----
> > > From: "Joe Gatewood" <[email protected]>
> > > To: <[email protected]>
> > > Sent: Friday, March 14, 2003 6:01 PM
> > > Subject: RE: [E-Q&A] Torgue strain gauge
> > >
> > >
> > > > Gerry,
> > > >
> > > > Would the added weight of an encoder disk cause you a problem? If
not
> I
> > > > would suggest adding an encoder disk and a simple photodiode based
> > > > detector. You could then monitor the pulse frequency and look for
> > > > changes that would correspond to the mechanical pulses. The actual
> > > > force calculation if needed would be straight forward physics. I
> would
> > > > probably have to dig out my physics texts but the basic idea would
be
> to
> > > > determine the mass and acceleration to give you the applied force.
> > > >
> > > > Joe
> > > >
> > > > -----Original Message-----
> > > > From: [email protected]
> > > > [mailto:[email protected]] On Behalf Of Gerry
Sorensen
> > > > Sent: Friday, March 14, 2003 6:09 AM
> > > > To: Elec-qa (E-mail)
> > > > Subject: [E-Q&A] Torgue strain gauge
> > > >
> > > > I'm testing a system that is composed of a DC motor which drives,
> > > > through a
> > > > cogged belt, a small flywheel with little mass. The flywheel has
> > > > positive
> > > > and negative drag points (mechanical pulses) my goal is to measure
> these
> > > > mechanical pulses. My collection system is LabView and a national
A/D
> > > > board
> > > > set up for differential analog measurements.
> > > >
> > > > My first thought, and scrub, was to add a tension pulley from a
pivot
> > > > arm
> > > > that is hooked to a Torque Strain Gauge. Since this is a low budget
> test
> > > > and
> > > > because Torque strain gauges are quite expensive this method is
> > > > impractical.
> > > >
> > > >
> > > > My second thought was to again use the tension pulley and a pivot
arm
> > > > hooked
> > > > to a very accurate pot. Run a small current through the pot and
> measure
> > > > the
> > > > voltage. The problem here is to get accurate positive and negative
> data
> >
> > > > I
> > > > have to have the tension pulley in the middle of a travel range with
> > > > identical spring tension for both travel directions.
> > > >
> > > > My third thought was to monitor the Current of the motor. This seems
> > > > like
> > > > the cheapest and best solution; however, I suspect the current
pulses
> > > > are
> > > > going to be really small.
> > > >
> > > > Does anyone in this group have any suggestions on the best way to do
> > > > this?
> > > > I'd appreciate any help I can get
> > > > Gerry
> > > >
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