[simpits-tech] Next question Possible answer

[John Miguez]

Leo Lavaca has a small company called Beta Innovations that designs and
sells control boards for flight simming.  His Plasma boards are very
inexpensive and can handle every thing from pots to hall effect sensors,
LVDT and more.  It has jitter filters and allows to select multiple
steps on your pots.

I used one of his mini Plasma boards for my control stick and it works
like a charm.  I have but not used one of the plasma cards.  I will hook
up throttles, stick and rudders to it along with the stick and throttle
buttons.

If you think it might help you check him out at
http://www.betainnovations.com/

John

-----Original Message-----
From: Marv De Beque [mailto:mdebeque at woh.rr.com] 
Sent: Friday, July 16, 2004 4:41 PM
To: Simulator Cockpit tech list
Subject: Re: [simpits-tech] Next question


Linear and rotary motion can be best detected with LVDT.  Essentially,
it is
an 3-coil AC transformer that has a magnetically permeable slug.  The
downside is the electrical interface is a little complicated, but they
are
extremely accurate and the longevity is nearly infinite.

Hall Effect generally looks for a reversal of the magnetic field and
measures the magnitude of the differential.  Interfacing is pretty
simple
since the Hall Effect produces a linear voltage output.  Some care must
be
taken with the mechanical design to insure a true linear response.

Capacitance works with small changes in distance, but I think it has the
potential to be finicky.

The problem with position sensing pots is the longevity stinks.  You can
get
precision pots that have better lifespan.  They are simple to interface.

Marv


On 7/16/04 3:24 PM, "Fred Mahone" <fred.mahone at vt.edu> wrote:

> OK, I have been following the questions and comments about analog and
> digital joysticks and throttles.
> 
> Now the question, Are there any circuits that can take linear and
rotary
> motion and convert it to a computer compatible signal,
> be better than potentiometers, and remember the position so the
control
> does not have to be re-calibrated each time you start?
> 
> I have looked at various schemes, hall effect, optical sensors,
variable
> capacitors and have not seen anything that is as good as a position
sensing
> potentiometer like used to send position to an electronic ignition in
a
> car. I would guess there are probably ones based on stress to some
element
> but have not found any, as yet.
> 
> My Bell cyclic pivot will have two linear movements, the anti-torque
will
> be either rotary or linear (I can go either way), collective will be
> rotary, and if I add the throttle, linear.
> 
> Any web site information would be appreciated.
> 
> Fred Mahone
> 
> _______________________________________________
> Simpits-tech mailing list
> Simpits-tech at simpits.org
> http://www.simpits.org/mailman/listinfo/simpits-tech
> To unsubscribe, please see the instructions at the bottom of the above
page.
> Thanks!