LaFonte Group can turn off permanent magnet without work

[Bruce_TPU]

Testing through the night also. More to come.
Butch

Hi Butch,

You may also use "rust", also known as "red Iron oxide" and is also available cheap on Ebay.

While iron possesses the necessary magnetic properties, it is also electrically conductive. Eddy currents are circulating currents in the core induced by a magnetic field emitted by your spinning rotor, as you well know. These electric currents are undesirable. The core is acting much like a shorted secondary winding. They are power-robbing losses that convert your magnetic switch to a massive cog.

On the other hand, rust (iron oxide) is a nonconductor of electric current. The high resistivity of rust reduces eddy current losses. Since iron is also a conductor of electric current and the goal here is to minimize eddy currents, which is why the construction of the core is made up of a stack of thin plates of iron (laminations) which are insulated from each other by an oxide (rust-like) coating. This confines the eddy currents and prevents them from circulating between the laminations. The higher resistance created results in a reduction of power losses within the core.

What’s this mean in plain English? Back in the early years, manufacturers of laminations intentionally exposed their iron to moist air to encourage rust to naturally form on the surfaces as an insulator! Like a fine patina on an antique bronze the rust on your transformer could be viewed as badge of honor. You can actually expect some improvements in output and lower losses as rust develops or is used.

If you are bothered by the cosmetic aspect of rust, never scrape off the rust to the point of exposing bare metal because you will bring back those nasty eddy currents. Instead, brush off the loose particles and re-paint the area with varnish.

Rust is your answer.  Thinly sandwiched between laminates, or used soley by itself.

Cheers,

Bruce

[hartiberlin]

Well Bruce,
but it looks like Mark did build the parts from solid iron,
so no laminates available as long as he can´t splice or saw the solid iron
parts up...

So it would have been much better if the core would
have completely been build from
black iron oxide from the start on.

( Red iron oxide is not magnetic, only the black one !)

[Blainiac]

I was at work when I thought of this configuration...  Not very useful but it was fun tinkering with.  Basically it's the same thing with two rotors (out of sync 180 degrees) sharing the two places you put the coils.

[Bruce_TPU]

Well Bruce,
but it looks like Mark did build the parts from solid iron,
so no laminates available as long as he can´t splice or saw the solid iron
parts up...

So it would have been much better if the core would
have completely been build from
black iron oxide from the start on.

( Red iron oxide is not magnetic, only the black one !)

I hate to say it, but they will need to rebuild their core.  I would suggest building two differant ones...One with laminate, seperated by iron oxide, and the second one completely from black iron oxide, and testing them both.

Cheers,

Bruce

[Butch LaFonte]

I was at work when I thought of this configuration...  Not very useful but it was fun tinkering with.  Basically it's the same thing with two rotors (out of sync 180 degrees) sharing the two places you put the coils.

I wonder, does this even need the slots in the stator?
Butch