Gyros and Compass Modules

[protek@shreve.net]

Bill,
    There are a series of small solid state gyros now available.  All to my
knowledge are "Rate" gyros.  These output a voltage related to the rate of
turning for a given axis.  The cheapest that I have come across is from
Gyration.  They are listed on the Internet as www.gyration.com and have
specs available.  The problem with rate gyros is that unless you use
electronic integration, either analog or digital, of the rate to yield
angle, you can not use them as a compass.  And even if you do integrate
their outputs they drift to some degree.
    Your best bet is to purchase a used flux gate compass or get a Vector
brand compass module made by Precision Navigation form Jameco, Inc.  They
are also listed on the web and have specs on these modules available.
Check out Jameco.com The compass must be placed outside the sub where the
effects of magnetic fields are not going to cause too much error.  House it
in PVC, aluminum, brass or something that is not magnetic like iron.  These
modules are about $50, or $100 for the one with gimbles.  You will have to
use some electronic expertise to connect it to a readout of your own
design.  Or I think maybe they have a readout module you can purchase.
    I am in the process of adding the gimbled version to my sub.  The
problem that I have is that I am not sure how well it will work because my
hull seems very magnetic.  I may not be placing it far enough from the hull
for usable service.  I have mine in an acrylic tube with PVC ends and held
in place with coated aluminum bars.

Gary Boucher


At 08:32 AM 8/25/99 -0600, you wrote:
>      This might be a inexpensive solution for  a gyro compass.. (aircraft
>ones are air operated generally, and the electric  ones are expensive,
>although if you might be able to find a reasonable one at a  aircraft
>wrecker place or something..)     any comments, or smart types  that want
>to look into this for the rest of us...?????   bill