World Sea Fishing Forums banner

1 - 11 of 11 Posts

·
Registered
Joined
·
2,106 Posts
Discussion Starter #1
humour me but, on a mag elite how do the mags cause drag on the spool ?
to put it simpler how do they work
 
C

·
Guest
Joined
·
0 Posts
all spinning object create an electical field and all electrical fields are affected by magnets either that or its magic!
 

·
Registered
Joined
·
2,106 Posts
Discussion Starter #4
thanks guys , see ive had the reel stripped down to clean /oil a few times now and one thing bugged me - the spool wasnt magnetic and the mag holder was
i knew a magnetic field was involved someplace or there wouldnt be any mags
but didnt know about spinning and magnetic fields doh bit obvious when explained
 

·
Registered
Joined
·
2,380 Posts
I'll try and drag up some of distant memories of A Level Physics for this one. Any conductor moving through a non-uniform magnetic field will generate an electric force. The magnetic field is disturbed and creates eddy currents, the generation of the electric force causes drag on the spool slowing it down. The amount of braking imposed is directly proportional to the speed the conductor passes the magnet, therefore the faster the spool spins, the more braking effect there is.

I'm sure somebody will give a better answer than that but I think that's roughly the best way to describe it, if you want formulas and stuff then find somebody far more intelligent that me! :)

One thing that has always puzzled me, why do we never manage to zap ourselves with a few hundred volts during a cast if they generate electricity? :)

This is the principle used in most power generation, like wind turbines etc.
 

·
Registered
Joined
·
2,639 Posts
I'll try and drag up some of distant memories of A Level Physics for this one. Any conductor moving through a non-uniform magnetic field will generate an electric force. The magnetic field is disturbed and creates eddy currents, the generation of the electric force causes drag on the spool slowing it down. The amount of braking imposed is directly proportional to the speed the conductor passes the magnet, therefore the faster the spool spins, the more braking effect there is.

I'm sure somebody will give a better answer than that but I think that's roughly the best way to describe it, if you want formulas and stuff then find somebody far more intelligent that me! :)

One thing that has always puzzled me, why do we never manage to zap ourselves with a few hundred volts during a cast if they generate electricity? :)

This is the principle used in most power generation, like wind turbines etc.
Nice one ! In fact the eddy currents (generated in the conducting, but not magnetic, spool) create a weak magnetic field which is in opposition to the one that the fixed magnets set up.

The faster the spool spinning, and the closer the magnets are to it (so that it is in a stronger magnetic field) the stronger the eddy currents and so the greater the braking effect.
All this energy has to go somewhere and my guess is that it is slightly warming up the metal, by the eddy currents.

To get a usable voltage and current from a 'generator' or 'alternator' like this you have to prevent eddy currents {which waste the energy as they do in a mag reel} which is why real generators have insulated (by a very thin coating) wire wound to be at right angles to the magnetic field it is 'cutting'

I remember seeing an impressive demo on TV where a flat aluminium sheet was dropped (from a height) down some guides through a very strong magnetic field and suddenly slowed just before it would have "crashed" into the earth. They had it in mind as a safety brake on a funfair vertical drop-ride.
Come to think of it, the propulsion bit of the MagLev train must work like this ?
 

·
Registered
Joined
·
340 Posts
and, just a open thought, how does the polaritary of the mag setup affect the breaking of the spool - i.e; ++--, or +-+-+ etc. :g: but for fishing i dont suppose its worthwhile doing a physics degree to find out the affect/effect of polarity!!
 
1 - 11 of 11 Posts
Top