Magnetism electronic leash

[Steyr223]

Hello everyone just like the title says I was wondering if there's a way to make a magnetic leash for my dog or so to speak a wireless leash
Maybe a collar that's a coil I think it would have to be too heavy though and then maybe another one in my hand where when she got too far away it would pull back attract and if she got too close it would repel.
I think it would have to be done digitally though quick enough so it wouldn't smash her head if it pulls her too fast as it would need to repel.

Just a thought
Thanks

 

[Nigel Goodwin]

No.

 

[rjenkinsgb]

Magnetic interaction, to have any practical force, has a typical range of up to a few millimetres. Hand-held magnets that attract or repel with serious strength over several feet or more are pure fiction, sorry.

Magnets can be bigger, as with eg. those in MRI machines, which are phenomenally strong - but are massive, weigh many tons and run on superconductor coils submerged in liquid helium [or liquid nitrogen?] - and still only pull things strongly over a fairly short distance.

The reason is that the strength of attraction of magnets falls with the square of the distance; eg. an industrial lifting magnet rated to lift 5000Kg with a high safety margin when in contact with a large piece of metal (or at no more than 1/10th millimetre) will have a pull of around 1Kg or so at 10mm distance; 100x distance, 1/10000th the pull....

 

[Steyr223]

Thanks guys I thought maybe if i made the coils but yeah I didn't think so