STEORN DEMO LIVE & STREAM in Dublin, December 15th, 10 AM

[k4zep]

Can you show this RL network and how efficient it is. So you're saying one can take a flat loop core, get the current to spike up almost instantly (requires high voltage), followed by flat DC current?

Look through this: http://focus.ti.com/lit/an/slup100/slup100.pdf

Ends up a resistance in series with coil is a form of a snubber or RL network.


Ben

[PaulLowrance]

Look through this: http://focus.ti.com/lit/an/slup100/slup100.pdf

Ends up a resistance in series with coil is a form of a snubber or RL network.

The Steorn scope shows both the voltage and current are square wave. With an ordinary core there's no way around it that the voltage across the coil *must* spike up high and then rapidly drop to almost nothing in order to get a square wave current. But with a square loop core, it works out perfectly, as the current surges up immediately and then hits a brickwall as the inductance goes from extremely low to ultra high.

[gravityblock]

Hi GB,

After all the discussion about MetGlass, this on Steorn's forum:

Steorn 19 hours ago  permalink
overconfident:What core materials are you using?


Just a soft magnetic material - I will not go into the details - sorry.

Now how do you get almost 1H with 38 turns???

Ben

It's already been shown how to get almost 1H with 37 turns with the correct dimensions and permeability that matches the toroid Steorn is using with metglas and even with other materials with similar dimensions with less permeability.

"Soft magnetic material" means the domains turn easily (This is the second time I'm having to repeat this).  It also means the core won't hold it's magnetism after leaving the presence of an external field.  "Hard magnetic materials" maintains their magnetism after an external field is removed because their domains aren't easy to turn.  Hard magnetic materials are used in PM.

Steorn didn't exclude anything other than a PM or other similar materials by saying they used a soft magnetic material.  A high permeable material doesn't mean it's a hard material.  In fact, metglas is a very soft material even though it has a high permeablity.  Steorn almost through this entire thread off by making that simple statement.  Unbelievable.  They know we almost have this nut cracked and they're starting to worry IMO.  The way this is being reversed engineered before their eyes and at the speed it is happening must have them worried.

I'm really getting tired of defending everything I say.  I guess this post will lead to a few more pages because somebody will want to shoot it down.  Lol

Here's the reference material on soft magnetic materials, http://en.wikipedia.org/wiki/Coercivity  If you disagree with this then take it up with whoever wrote the article.


GB

[PaulLowrance]

It also means the core won't hold it's magnetism after leaving the presence of an external field.

Not necessarily. Ultra high permeability cores close to a million are a different animal. They're square loop (have high remanence ), but it takes almost nothing to change their domains.

[gyulasun]

HI FOLKS,

As someone already pointed out,  the measured nearly 1H inductance by Steorn includes the four toroidal coils in series. 
If this is really so, then the 1H should be divided by 4 if four coils are in series,  so this gives around 240-250mH for any one toroidal coil.

rgds, Gyula