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

[mondrasek]

It depends if the MAGAMP core is saturated. These cores saturate at only 0.57T, while steel saturates at ~ 1.8T. A common ferrite core saturates at only 0.35T to 0.5T.

So if the MAGAMP is not saturated, then it will be more attracted to the magnet than a steel core.

Have you confirmed this with a simple experiment?  Does a PM actually hold onto the bare Metglas cores better than the same PM holds onto a piece of steel (ignoring the different shapes of the core vs. steel you have to test)?

[PaulLowrance]

Have you confirmed this with a simple experiment?  Does a PM actually hold onto the bare Metglas cores better than the same PM holds onto a piece of steel (ignoring the different shapes of the core vs. steel you have to test)?

No, nor have I done a lot of obvious tests. One would need two exact cores in size to do such a comparison, but that's not necessary because that's what specs are for; i.e., saturation, permeability, etc. I know MAGAMP has ~ 1000 times higher permeability than a steel core. It requires a lot of energy to saturate a steel toroid core. I mean, a lot of energy relative to a Metglas MAGAMP core.

[PaulLowrance]

If the steel toroid core has 1000 times less permeability, and (1.8T / 0.57T) = 3.16 times saturation, then it requires 1000 * 3.16^2 = 10000 times more energy to saturate the steel core. 

[mondrasek]

No, nor have I done a lot of obvious tests. One would need two exact cores in size to do such a comparison, but that's not necessary because that's what specs are for; i.e., saturation, permeability, etc. I know MAGAMP has ~ 1000 times higher permeability than a steel core. It requires a lot of A to saturate a steel toroid core. I mean, a lot of energy relative to a Metglas MAGAMP core.

Paul, could you please indulge me with a test?  I appreciate using specs, but personally I need to have experience or seen evidence of the experiments that confirm those spec to solidify my understand sometimes.  All I want to know is if you can pull a PM off the Metglas cores more easily than any steel object.  I understand that test is completely subjective and geometries of the core vs. steel are important, but with such radically different "permeabilities" you should be able to confirm for me if the attraction "feels" the same, greater, or less.

I guess I just have trouble with the idea that a PM can attract anything with more force than steel.

Thanks,

M.

[PaulLowrance]

Paul, could you please indulge me with a test?  I appreciate using specs, but personally I need to have experience or seen evidence of the experiments that confirm those spec to solidify my understand sometimes.  All I want to know is if you can pull a PM off the Metglas cores more easily than any steel object.  I understand that test is completely subjective and geometries of the core vs. steel are important, but with such radically different "permeabilities" you should be able to confirm for me if the attraction "feels" the same, greater, or less.

I guess I just have trouble with the idea that a PM can attract anything with more force than steel.

Thanks,

M.

mondrasek,

I believe that I said steel will have the greatest pulling force if were talking about fields over 0.57T, but again what's important here is that it requires ~ 10000 times less energy for the coil to saturate a Metglas MAGAMP core than a steel toroid core of the same size. Sean made it clear in the recent Talks #2 that the Orbo does not produce a lot of power. Besides, the Metglas MAGAMP cores cost $2.65 each!

Where to buy the Metglas MAGAMP toroid cores:
http://www.overunity.com/index.php?topic=8411.msg222174#msg222174

A copy of my order form:
http://www.overunity.com/index.php?topic=8411.msg222189#msg222189

Also, I would not want to fool around with these cores because one slip with the NdFeB magnet and that's the end of the MAGAMP core. So no way Jose! Not going to do it.