Permanent Magnet: ON/OFF Mechanism...

[hartiberlin]

Try first with simple selfmade magnets from iron rods or rectangular iron rods. Magnetize them wit a Neodym magnet and then apply a 180khz current through the selfmade iron magnet at 90 degrees angle.

[PaulLowrance]

Hello everyone,

Now where has this great thread been hiding, lol. What a major breakthrough this would be.  I'll have to think about this idea and see what comes up.

Hi

I totaly agree with Hartiberlin - behaviour of coil
wound with iron wire is strange .
For example I produced a selenoid wound by iron wire
and this selenoid did not work . It surprised me.
Does somebody a theory why it is not working?

thanks

@kadora,
what exactly did you test ?
If you pulse the coil with square waves you will see no
Back EMF pulses coming from the coil, what a normal copper coil would do.
I guess this is because at lower current values the magnetic field is still completely
inside the iron of the coil. Maybe only higher currents will drive the magnet
field out of the iron wire..and then we would finally have Back EMF, when switching
off the current...
Or do you have another explanation ?

If the current reaches a certain point then the iron (iron wire) saturates. There are still fields inside the iron wire after saturation, but the addition of fields from the current continue beyond the wire.  When this occurs the iron wire contains no appreciable inductance. Below this current point the iron wire by itself has appreciable inductance.  This is easily demonstrated with FEMM so long as you make sure your FEMM magnetic iron properties has saturation level just like real life. For the most part I have to add a few BH points to the FEMM magnetic properties to simulate real saturation effect in materials.

Tao, thanks for posting all your information. If it's true, and we have no reason to believe it's not, then it's priceless!

Paul Lowrance

[mikestocks2006]

This maybe of interest.
Magnetic shielding, well it's more in line with tipping the "neutral plane" between two opposing and equall magnetic fields apparently using a much lower force than the resulting imbalance. Note the fliping of the poles right at the "neutral zone".
The principle is simple, and makes sense.

It could be fairly easy to build, if one has the basic materials and few simple tools.

Wesley W. Gary's Magnetic Motor

Harper's New Monthly Magazine

(March 1879, pp. 601-605)
http://www.rexresearch.com/gary/gary1.htm

[PaulLowrance]

I know there are various levels of resonance in magnetic materials, but was not aware of any standard set frequency. I know iron atoms typically flip at around a few ns, which would give a few hundred MHz resonance. On a larger scale we have avalanche effects, which are much slower and typically anywhere from a few ms to ns.  Also we know that all magnetic materials are internally saturated or near saturation due to domains. So it is very possible there's an atomic magnet resonance (AMR) akin to NMR (Nuclear Magnetic Resonance). 180 KHz doesn't sound unreasonable for such a resonance, but this would probably very between ferromagnetic based atoms such as iron or manganese or cobalt. Perhaps Iron based materials resonate at 180 KHz and Nickel based materials at perhaps a higher frequency.

If this is true then I sure would not want to put my hand near material where the entire magnetic is resonating. Not that it would be dangerous to look at but a good size chunk sure would generate a lot of voltage. I don't know why a square wave would be required except square waves apply more force is all.

Tao mentioned something very interesting about dielectrics. It's possible certain epoxies or even PM's have high dielectric, which could cause a strong E-field. Has anyone heard of E-fields affecting magnetic material. I think it requires extremely intense E-fields. That would be cool though and everyone's dream.

Paul Lowrance

[PaulLowrance]

I think this is an inductor inside a cap somewhat similar to a parallel RLC except there's also an additional cap in series with the L. We know that parallel LC has high resistance and requires low current from power source, but within the LC loop there is a lot of current. So obviously if we found the resonance and given high enough voltage there would be enough current cause the domains to form a loop around the magnet, which would of course cause the magnet to not work. It would be more difficult with NdFeB magnets because of their extremely high coercively. Something like Alnico would be great. I just can't see this working on ceramics because of their high electrical resistance.

I think if you keep trying you'll find the correct setup. I don't think it's a "free energy" source though. It probably would not consume too much current but I think 10 volts is a little to low, especially for NdFeB. May be 20+ volts and Alnico magnets.

tao, I think you have it. Just use a dual power source op-amp and some good mosfets, perhaps IRF540's. I had such a circuit, but I lost my HD last month. Here's a good 50% duty cycle 555 timer:

see the last circuit on page:
http://wolfstone.halloweenhost.com/TechBase/com555_555TimerCalc.html

Paul Lowrance