TheBackShed.com

Forum Index : Windmills : Dual F&P Mill stop

Page 2 of 2

Author

Message

Rastus

Guru

Joined: 29/10/2010
Location: Australia
Posts: 301

Posted: 11:03am 19 Jun 2011

Copy link to clipboard

Print this post

Hi to all,
I hope you don't mind me reviving a dead horse,(this thread)I've recently heard of eddy brakes and would like to know more about them,with a view to including one on a duall F&P mill.Can the "brains trust" help explain how they work?How they are made?and how effective they are? I hope someone can help!Cheers Rastus

see Rastus graduate advise generously

Rastus

Guru

Joined: 29/10/2010
Location: Australia
Posts: 301

Posted: 01:50pm 20 Jun 2011

Copy link to clipboard

Print this post

Rastus said Hi to all,
I hope you don't mind me reviving a dead horse,(this thread)I've recently heard of eddy brakes and would like to know more about them,with a view to including one on a duall F&P mill.Can the "brains trust" help explain how they work?How they are made?and how effective they are? I hope someone can help!Cheers Rastus

a better description might help! Apparently "eddy current brakes" are an electrical system used to slow down speeding machines gradually.The name eddy is not related to the person who designed or made them to my knowledge

see Rastus graduate advise generously

Tinker

Guru

Joined: 07/11/2007
Location: Australia
Posts: 1904

Posted: 02:07pm 20 Jun 2011

Copy link to clipboard

Print this post

Rastus said

Rastus, imagine an ordinary disk brake where the brake pads have been replaced by a powerful magnet - you now have an eddy current brake.
The magnet does not touch the disk but is as close as practical to it. As the disk rotates it moves past the magnets on each side, this action induces electrical currents within the brake disk and these currents in turn induce a magnetic field that opposes that of the permanent magnets. Hence you get a braking effect.

Perhaps it may help you to trawl the net a bit more on that subject if you are interested in more detail how it works. Some of us have studied it at TAFE or other institutions and you may gather its not something explained in a short forum message.

BTW, the name "eddy" current derives from eddies as you see in river currents - side effects of the main current, or, in the above case, side effects of the main magnetic field in the moving disk. The disk *must* move to generate eddy currents, as a brake its useless when stationary.

Klaus

Rastus

Guru

Joined: 29/10/2010
Location: Australia
Posts: 301

Posted: 02:00pm 21 Jun 2011

Copy link to clipboard

Print this post

Hi Klaus,
The explanation you've provided is not difficult to grasp,however the internet references I read for a few hrs made my head spin.They were well over my head,obviously written by proffessionals for proffessionals.I've since done a search on "How things work" and that was more my level of understanding.It showed a uni proto type for NASA using bar coil mags with a central aluminium disc.The electro mags when energised stopped (braked) an electric motor.The size of the brake looked adequate for a F&P mill and only used half the possible magnetic area.I have a few thoughts about how they could be worth while.They could be applied to keep the head tottering at furl longer exstracting steadier power in higher winds safely,although that would depend on how much power is needed to energise the electro magnets.There may be room to include it in the dump load circuit and in addition provide a "run away" fail safe.Do you think any of these ideas could have merit?Cheers Rastus

see Rastus graduate advise generously

Page 2 of 2

Print this page

To reply to this topic, you need to log in.