perendev power/magnetic motor

[bradles1330]

Well I'm just a kid entering college in the fall, so my understandings of the mechanics of these types of motors are pretty rudimentary, as well as the physics involved with the output, but has anyone heard of these little magnetic motors that are set to be put out by Perendev Power? They appear to be the real deal, producing between 300 kW and 4 mW of power. That is what, like, 400 horsepower for the 300 kW? Maybe I am thinking about this completely wrong, but could you just hook that directly to a shaft and power a boat with that? Seems logical to me...
http://www.perendev-power.com

[FAST FRED]

That is what, like, 400 horsepower for the 300 kW? Maybe I am thinking about this completely wrong, but could you just hook that directly to a shaft and power a boat with that? Seems logical to me...

Yup,

Untill you begin to contemplate how to power the electric motor.

400hp worth of batteries for even an hour would be measured in TONS.

A motor generator just induces system losses.
The tried & true prop and gearbox with std shaft is the most efficent & common (read cheap to by & service) system.

Unless you have a 400KW nuke plant that fits in a beer cooler.

FAST FRED

[marshmat]

The simple answer is, it's probably a plain old electric motor. There are plenty of physics and mech.eng textbooks that explain what goes on inside the thing, it's hardly new news. You also need to consider what Fred says- that electricity's gotta come from somewhere. Usually that means diesel generators. Which means you're thinking diesel-electric, since the batteries for pure electric would be huge. Once you start thinking diesel-electric, there are plenty of threads on here to look at- just use the Search button.

Now about that Perendev company. They also sell "magnetic gold health rings" for 550 euro. They sell a hodgepodge of unrelated products with no brand names and no spec sheets. They make vague references to their "magnetic motor" producing power in a way that makes it sound like it violates the First Law of Thermodynamics. Magnetic fields, after all, do not and cannot do work. In other words, Perendev ain't credible and they probably ain't fully legit. So I'd steer clear, and drop by the library on the way.

[jehardiman]

You can design and build a "magnet only" permanent magnet motor, but this is the first I have heard of anybody offering a major one as a prime mover for sale. The idea of one of these motors is old (first working model I'm aware of is mid '70's with the idea of a fridge sized unit in every house) and several have been built with various results. See this site: http://freeenergynews.com/Directory/...ors/index.html.

NOTE: These are not "perpetual motion machines" and the energy is definitely not free. The source of power is the attractive/repulsive effect of magnetism, which is linked back to electron spin. Eventually, the magnets will de-perm and they will stop working. Also, the magnetic flux density needed is very high and they require rare-earth magnets to work. Now they aren’t called rare earths for nothing, and most of the energy balances I've seen on the subject show that more energy is needed to form the parts than will ever be delivered during the engineering life of the product (like a lot of solar cells). They are also heavy, and the high flux field is problematic for electronics. Many small, low power, high cost sites (such as un-manned sensor/telemetry stations) can benefit from this technology, but as of yet, I haven’t heard on any being installed at a commercial level.

[marshmat]

Ahh, I see what you mean, jehardi. I'm not entirely unfamiliar with such things, I just never would have imagined anyone would be brazen enough to try to sell one as a motor! And the website linked in the first post didn't really make that clear...
As you say, it is possible to build a device that will rotate a shaft due to magnetism alone. But it does degauss the magnets over time. Essentially it is a means of storing energy as a magnetic field (grossly simplified, yes, but basically the idea). You can never get more energy out of it than was put in to create the magnetic field in the first place. It's the same idea as an inductor, only using permanent magnets instead of windings. You store energy in the magnetic field when the magnets are made; this is released over the life of the product until there is none left.
It's hardly an efficient way of storing energy, and although the devices are an interesting scientific curiosity, they will almost certainly never be a practical motor.

[Guillermo]

Interesting, though: http://peswiki.com/index.php/Directo...tic_Motors:PM3

[jehardiman]

Here is a US Patent (4,151,431) and 1980 article on the Johnson type permanent magnet motor.

http://www.newebmasters.com/freeenergy/sm.html

[VladZenin]

Could you tell me please why nobody has seen a working permanent magnet motor?

[jehardiman]

Originally Posted by VladZenin

Could you tell me please why nobody have seen a working permanent magnet motor?

They are fringe items considered toys and, as has been stated, they have problems keeping perm. That's why I find the Perendev offer so interesting. I have no doubt that they can be built, but wether they can be made comerically viable is another issue. Like wind and wave power farms, this is a devloping tech, and may go the way of DC power, BetaMax, or LaserDisks.

[marshmat]

I still have to call bull on the company, though. Looked through their site again.... they're marketing the thing as if it's a perpetual motion machine (which it is not), just churning out 300 kW indefinitely with no input of energy from anywhere. It will most certainly not do this for very long. And the company's repeatedly cancelled demonstrations for outside observers attempting to validate it's claims.
Let's put it this way. If these things really were what their inventors claim, then the serious engineering community would be using them in actual, practical applications. The principles behind the PMM are well known, and it's known that every example to date self-destructs with use. If they really did work as claimed, there would certainly be more than a few fringe inventors peddling the things.

[Guillermo]

I think perpetual machines inventors don't realize the "Maxwell's demon" within their devices. Many times difficult to find, he's always there increasing entropy.
See: http://en.wikipedia.org/wiki/Maxwell's_demon

[VladZenin]

I asked myself: Is there free energy in magnets? Here is an answer http://my.execpc.com/~rhoadley/magfree.htm

[marshmat]

It seems we have a disconnect here between the real engineers/scientists and the wannabe-a-millionare inventors who aren't engineers/scientists.....

[VladZenin]

We are equal in the face of physical laws.