autohelm compass

[robertj]

any one know if battery cables within 1' of the electronic compass of a auto helm will effect it adversely?
Will lead help or hinder more?

 

[earlybird]

I'll reply, in the absence of anyone who knows better.
It depends on the amperage. 100+ amps of starter current might affect it; 20 amps of battery charging current; not much effect. In practice I wouldn't expect any real problem unless you set your course to the nearest degree.
All IMHO of course.

 

[guernseyman]

I'll reply, in the absence of anyone who knows better.
It depends on the amperage. 100+ amps of starter current might affect it; 20 amps of battery charging current; not much effect. In practice I wouldn't expect any real problem unless you set your course to the nearest degree.
All IMHO of course.

I may be rusty but the magnetic field at a distance of 1 foot from a cable carrying 100 amps would be about 0.6 gauss i.e about the same as the earth's magnetic field.
Less current would reduce the field proportionally.

 

[lpdsn]

any one know if battery cables within 1' of the electronic compass of a auto helm will effect it adversely?
Will lead help or hinder more?

Get a hand bearing compass and place it next to the Autohelm compass. Move it towards and away from the battery cable when it is carrying high loads. Then you'll be able to measure the effect. (the compasses will interact but that shouldn't mess up the experiment too much)

 

[VicS]

Get a hand bearing compass and place it next to the Autohelm compass. Move it towards and away from the battery cable when it is carrying high loads. Then you'll be able to measure the effect. (the compasses will interact but that shouldn't mess up the experiment too much)

Perhaps possible to do that without the Autohelm in position.
However the effect will vary according to the relative directions of the two fields.

Personally I'd feel inclined to dig out the old school Physics book and calculate the possible effect. Not at this time of night though.

One for William in Australia.

 

[oldsaltoz]

You can remove most of your problem by simply twisting the live and return around each other (old school sailor here).

Good luck and fair winds.

 

[robertj]

It's cable to the anchor windlass so not concerned when in operation just as I have to route said cables fairly close to the compass unit.

 

[VicS]

It's cable to the anchor windlass so not concerned when in operation just as I have to route said cables fairly close to the compass unit.

No problem then if you are not using the autohelm when you operate the windlass.

 

[robertj]

thanks all

 

[Birdseye]

any one know if battery cables within 1' of the electronic compass of a auto helm will effect it adversely?
Will lead help or hinder more?

depens on the current it is carrying. The strength of the magnetic field varies with the current.