On 01 November 2019 at 15:35 Brent Cameron <brentcameron61@...> wrote:

Bill, a fluxgate isn’t a proprietary Raymarine term.  It is a relatively simple device consisting of iron cores surrounded by primary and secondary copper windings.  It is used to determine the magnetic fields of the earth.  They need to be level against the horizon to work and the old ones are usually gimbal stabilized or mounted in some sort of dampening fluid like a compass or use may even use electronic dampening so that it doesn’t swing with the boat yawing, pitching and rolling.  Newer models are often combined with gyro compasses which use the principle of a top spinning maintaining its orientation in space despite the world turning around it.  The fluxgate provides a stable long term reference to the magnetic field while the gyro provides short term dynamic stability and allows dampening of any external forces on it.  The challenge is that this takes a fair bit of energy to keep that gyroscope spinning and of course advances occur.  Now even newer units combine all this by using 3-axis fluxgates with the horizon vector being determined by a line perpendicular to gravity all done inside a small chip in silicon.  Y ou likely have one in your pocket with your iPhone.   

Brent Cameron, Future Amel owner & Amel Owner's Registry Moderator

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Brent Cameron

Future Amel Owner & Amel Owner Registry Moderator

Oro-Medonte, Ontario, Canada