Ferro fluid cores?

[Hrothgar]

The question hit me today at work. "Has anyone tried ferro-fluid cores?"

Then they came pouring out. What frequencies could they take? Would it be good to keep cool since you could circulate the core material itself to heat sinks? Would different densities of ferro fluid affect the maximum frequency? Would it make for a dense enough core to be useful.

So is the idea intriguing enough to speculate on?

[Cornboy 555]

The question hit me today at work. "Has anyone tried ferro-fluid cores?"

Then they came pouring out. What frequencies could they take? Would it be good to keep cool since you could circulate the core material itself to heat sinks? Would different densities of ferro fluid affect the maximum frequency? Would it make for a dense enough core to be useful.

So is the idea intriguing enough to speculate on?

Intriguing indeed Hrothger, if used in a rotor core, it could possibly be circulated by centrifugal force alone, maybe.

Regards Cornboy.

[MonsieurM]

had the same thought yesterday .... found this video that got me wondering :




Magnetic Thinking Putty is Crazy Awesome! - YouTube

the putty has some quite interesting behavior

[IndianaBoys]

Hrothgar,

Ferrofluid is very responsive.

Maybe someone can give it a whirl and let us know how well it works as a core material.

Watch how responsive ferrofluid is to light/heat!
Watch how responsive ferrofluid is to light/heat! - YouTube

Life in the Superlattice Order
Life in the Superlattice Order - YouTube

super simple quick way to make ferrofluid
super simple quick way to make ferrofluid - YouTube

[Hrothgar]

Thanks for the links

It would really be sweet just to wind a core place it in a can, pour your core on top of it then seal it after trailing out some leads. I wonder how it would effect a coil to have iron between every winding?

[Hrothgar]

Time to redneck this puppy!

I finally got a budget set aside for construction of a new kind of M.E.G (my wife said ok) and I've decided that a liquid core would be the easiest way to go. I'll get parts over the next few months. The deciding factors included:

1. I'm tired of staring at that stupid welder transformer thinking what a pain it will be cutting all those laminations the way my finicky butt will be satisfied.
2. I figured that it would be easier to build my experimental dispersed core directionally biased injected flux processing coil by rolling it in cloth instead of folding it in laminations. (I'll just call it a jet coil)
3. A liquid core means I can build the unit out of PVC.

I've got a loose estimate of $400 in materials for the non electronic parts

Just for conversations sake what does a wire inductance of 17377.113431nH mean in layman's terms?

[gyula]

....
Just for conversations sake what does a wire inductance of 17377.113431nH mean in layman's terms?

Hi Hrothgar,

There is no much sense in expressing an inductance with such precision, it would be practically just enough to say it as 17.37 uH or maybe 17.4 uH.
There are laboratory L meters which may be able to show measured inductance with a precision just approaching your shown nH number, just approaching... 11 digits in nH has no practical value, it is impossible to check.

Re on your new kind of MEG what can you tell about it some more? apart from the liquid core which surely gives easiness in construction.

rgds, Gyula

[Hrothgar]

Devils in the details

Hi Hrothgar,
Re on your new kind of MEG what can you tell about it some more? apart from the liquid core which surely gives easiness in construction.

rgds, Gyula

Each Flux coil for ease of construction is made from a 6" wide 50' long piece of aluminium flashing folded in half with a cloth strip insert (the core material) then it is rolled up and inserted into a pvc pipe. That specific layering (in theory)will guide the flux down only one side of the "wire" letting the flux induce a uniform rotating counter field. Two magnets pointing set to naturally feed each other in a loop until a trigger coil blocks the path forcing them to complete the magnetic circuit via the coils. when the trigger is released the magnets feed each other leaving the coils flux free. Unlike the patented meg this model fires both coils at the same time. The hardest part I can see is balancing the Magnet positions to make the trigger strength required reasonable.

The decentralized core gives this coil about 25 square feet of core contact with the winding. If I'm correct the flux coil amounts to an oversized resistor if you try to put electricity through it but should process the flux way better than a standard coil. Hence me calling it biased.

g2go wife is calling me to bed

[gyula]

Hi Hrothgar,

Thanks for the details. In your left hand side drawing, does the pink color represent ferro fluid? If yes and if I see it correctly, the permanent magnets are surrounded (embedded) into the ferro fluid? because in that case certain amount of the available flux from the magnets is shunted directly via the fluid, so less flux would be available for inducing in the coils, I believe. What do you think?

[Hrothgar]

Sorry was in a hurry when I made that.

Hi Hrothgar,

Thanks for the details. In your left hand side drawing, does the pink color represent ferro fluid? If yes and if I see it correctly, the permanent magnets are surrounded (embedded) into the ferro fluid? because in that case certain amount of the available flux from the magnets is shunted directly via the fluid, so less flux would be available for inducing in the coils, I believe. What do you think?

No the ferro fluid doesn't surround the magnets but I am going to use four ring magnets each on the ends of two iron pipes to turn them into longer magnets. that should keep the flux oriented nicely and the pink does represent the general area the fluid will fill. I'm still deciding if I will put the trigger coils inside or outside the pvc. Also I think I will need to "condition" the flux. In the new drawing here I've omitted one of the trigger coils as two are redundant as the design only has one fire position. Also, by condition I mean insert a normal emf mixed with the neo pulse to give it some wave like properties instead of just being a shotgun blast. I figured I'd just take the ground from the trigger coil and lead it into the conditioner coils then after connecting the final ground from the conditioner coils I'd link the beginning and end of the conditioner coils with a diode set to feed toward the positive. It may sound crazy but I figured that if any boost happened in the conditioner then it wouldn't be trying to suck more power from the stalled trigger, Instead it would free wheel and resonate the flux more.

disclaimer: I'm just a warehouse grunt. I have no electrical background except for trying to build Imhoteps charger and sticking (as a small child)my fingers in light sockets for the fun of it.

[gyula]

Okay, I see. I think if the pvc pipe has a wall thickness of only 1-2mm, then the trigger coil could go outside without any problem.
Your 'condition' coils sound interesting, I think even for solid cores they may serve some better flux steering, not aware of any attempts to use such.
Good luck! Gyula

[indio007]

How might the ferrofluid work inside a Rodin Coil?

[Hrothgar]

Don't have a clue...

How might the ferrofluid work inside a Rodin Coil?

I'm using it for the theoretical high hertz tolerance and for ease of making a custom core. Not necessarily the permeability.

That is a good question.

What I do have a clue on is that is winding one would be problematic in that you would still have to wind it around a doughnut even if it is porous to absorb the fluid you still need to encase it in something. If it didn't need to spiral around itself then you could wind it insert it in a flexible hose then seal the ends together.

It looks to me that you'll need to make a 2 piece case to epoxy together.
Just remember that you'll need to secure the coils otherwise it will be a bundle of wiggling worms inside the toroid. A Magnetic putty might suit your project.

I'd like to see a ferro-fluid that hydro-clusters.

[indio007]

I'm using it for the theoretical high hertz tolerance and for ease of making a custom core. Not necessarily the permeability.

That is a good question.

What I do have a clue on is that is winding one would be problematic in that you would still have to wind it around a doughnut even if it is porous to absorb the fluid you still need to encase it in something. If it didn't need to spiral around itself then you could wind it insert it in a flexible hose then seal the ends together.

It looks to me that you'll need to make a 2 piece case to epoxy together.
Just remember that you'll need to secure the coils otherwise it will be a bundle of wiggling worms inside the toroid. A Magnetic putty might suit your project.

I'd like to see a ferro-fluid that hydro-clusters.

By inside, I meant center of the donut. Kind of like this video of a spherical magnet in the center of one.

Rodin Coil Effects 5.1 - Neosphere Levitation - YouTube

[Hrothgar]

By inside, I meant center of the donut. Kind of like this video of a spherical magnet in the center of one.

Rodin Coil Effects 5.1 - Neosphere Levitation - YouTube

Either dip your coil in wax or put it in a bag. also do it outside and don't wear any of your favourite cloths while trying it out. Oh, don't forget goggles. otherwise tell us if it is awesome.