Manipulating analogue compass with electric field generator?

Projects General Guidance
1

Just watching a couple of video's on this subject, but they where all theoretical.

Question: I have a compass and I want it to react the way I want. I don't care about the real magnetic north, I want full 360 degrees control of the unit. Can it be done with some savvie electronics?

By creating a magnetic field, and to be able to adjust that, could do the trick. The needle of a compass is a little magnet, mostly suspended with a pivot on a fixed point. so it can move around freely. If, in close proximity a second (electro/electronic) magnet is introduced on another fixed point, it should be able to manipulate it, at least, that's what I would think.

Does anyone has some idea or experience with it?

EDIT: The second electro magnet/magnetic field generator can also be above the compass, that would make it easier I would image...

2

At it's most simple a bar magnet above or below the needle on a 360 degree servo/stepper motor.

3

Yes thats an option...

Any ideas of an IC that can simulate this? no moving parts then (A)

4

Solid state device would probably be 4 or more electromagnetic coils around the compass and by turning on & varying the coil fields of 2 or more at the same time you could drive the needle round.

5

Riva:
Solid state device would probably be 4 or more electromagnetic coils around the compass and by turning on & varying the coil fields of 2 or more at the same time you could drive the needle round.

You only need 2, at right angles. It's all a synchronous AC motor is, really.

6

Right, now that I think of it, it's all looking clear :slight_smile:

By putting 4 coils, at 0, 90, 180 and 270 degrees and adjusting the power between them, it'll be possible to do it.

7

C-F-K:
Right, now that I think of it, it's all looking clear :slight_smile:

By putting 4 coils, at 0, 90, 180 and 270 degrees and adjusting the power between them, it'll be possible to do it.

The pairs 0-180 and 90-270 can be driven by the same circuit. You won't need 4 drivers.

8

Helmholtz coils can be used to generate a desired magnetic field. Usually 6 are used, 4 cancel the Earth's field.

9

aarg:
The pairs 0-180 and 90-270 can be driven by the same circuit. You won't need 4 drivers.

Well, you will actually, as to drive two single coils, you will need two H-bridges.