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Well this might be a little hard to explain in plain words. But is important that the rotor is free to move-on after an attraction to a given pole.
Now the problem is that the fingers of the stator will not ‘instantly’ demagnetize. If you look at if closely, the finger after the electro magnets has been turned off (or any electro magnet steel for that matter) needs some time to become ‘magnetically neutral’ again. This ‘demagnetization speed’ depends on the steel type of the core material and more specific on the hysteresis curve.
Now back to the attraction motor.
The problem exists when the fingers of the stator are as wide as the fingers on the rotor. You see, you want to maximize the ‘attraction interaction’ between the stator and rotor, so you keep the attraction pulse going until top dead center – in other words when the stator and rotor fingers are truly aligned. Now you need to shut off input power, so the rotor is not attracted anymore and is able to continue rotation to the next attraction cycle.
BUT IF you shut off the power at top dead center you have not yet fully demagnetized the poles. Since like I explained above, there is a relaxation time involved which takes time to fully become neutral. So in other words if you shut off power at top dead center you have not fully ‘released’ the rotor from the stators ‘magnetic grip’. And since it is at top dead center it wants, and must rotate onwards. But is ‘cannot’ since the steel is still in its natural process of becoming magnetically neutral, and thus is still somewhat magnetized. And so the free rotation after the attraction cycle becomes retarded to an extent.
Now this is where my suggested ‘wider rotor fingers’ come in.
The coil will shut off when the surface of the rotor fully registers with the surface of the stator. Now with the attraction phase over, the core will start to demagnetize. In this case that is fine since the rotor still has some way to go before it starts to leave the stator core. So by the time the rotor starts to leave the stator finger area, the demagnetization should be complete and thus the rotor can rotate freely and is not retarded. I make it sound like this ‘steel demagnetization’ takes ages, which is not so of course, but it will hinder the free rotation of the rotor if the rotor- and stator fingers are of equal width. This btw is the reason why commercial variable reluctance drives have a short ‘demagnetization pulse’ (just a short opposite-polarity pulse to speed up the core demagnetization)
Hope you can understand what I try to communicate here.
If not, let me know.
And please let me know if this ‘alteration of a normal induction motor setup' will result in a No Back-emf motor, because I have a bit of trouble getting the interaction between the various poles that are being generated.
Kind regards,
Steven
Steven,
If you read through all of my posts, you will find numerous differences between what you are proposing and what I am proposing. But its your motor design. Its up to you to build it, test it and tell us what it does. I think the design includes a number of features that will limit its performance.
I am disappointed that no one else has commented on your idea. I applaud you for proposing a unique design but will not critique it myself.
Well this is certainly an eye opening DVD, thanks Peter.
I was just wondering about not having magnets in attraction motors which may lead to lower overall HP than normal DC motors which have magnets and which they generate counter electricity.
Normal DC motors never pulse they just change the direction of the current flow on the electromagnet on each half revolution, So that changing of direction requires opposing the collapsed field instead of capturing it which causes more current to be drawn. This is besides overcoming the generator effect of the motor (Am I correct?). (Which one is actually termed as "Back EMF"? maybe both)
But normal DC motors use magnets to increase torque, I mean doesn't eliminating magnets like in attraction motors decrease the overall horsepower (magnets provide free energy).
And another thing I was wondering about. If we can get more horsepower for less electricity then We may be able to do this in reverse: Why not build a generator to produce more electricity than the input mechanical energy required. This may be alot easier.
Hi Peter,
my parts are now ready. I did not post for so long, because my lathe broke down and I had to order some custom made screws to hold the plates together and that took some time. Now all the plates have some layers of varnish on them and the last layer also acts as glue and holds these plates together. Now I just need to drill a bigger hole in the X rotor middle to fit on the shaft tight. Also I need to do some lathe work to fit the rotor into the startor piece, but since my lathe is broken, I will have to get this job done by a local craftsman in his shop. This will take some time as he is always busy Here's a picture:
Thanks
Gatis
It's better to wear off by working than to rust by doing nothing.
Here I read a sentence from the book titled "Theory and Calculations of Electrical Circuits" published in 1917:
"Investigations and calculations dealing with one form of
energy only, as electromagnetic energy, or mechanical energy,
usually are relatively simple and can be carried out with very
high accuracy.Difficulties, however, arise when the calculation
involves the relation between several different forms of energy,
as electric energy and mechanical energy. While the elementary
relations between different forms of energy are relatively simple,
the calculation involving a transformation from one form of
energy to another, usually becomes so complex, that it either can
not be carried out at all, or even only approximate calculation
becomes rather laborious and at the same time gives only a low
degree of accuracy. In most calculations involving the trans-
formation between different forms of energy, it is therefore
preferable not to consider the relations between the different
forms of energy at all, but to use the law of conservation of energy
to relate the different forms of energy, which are involved."
They have not realized that magnetic energy is not created by electricity and it is a sibling that exists with any electron flow. Thus magnetic fields are not created, but they exist. And we do not "convert" magnetic energy to mechanical, but we use it as a natural force to do mechanical work. The law of energy conservation may be true, but I don't think that any "conversion" takes place in here, that's why they think that it is complex and cannot therefore be calculated.
Hi Jetijs,
Good work man. Only one word of 'warning', It is very likely that drilling a hole through the X rotor will not be very precise. Drills tend to wobble and 'search' their own way. You could be a few tenth of a degree off easily. Another method is called "Boring" in machining terms. It is a precise way of making exact holes.
Well like I said, very good work and keep us updated.
Thanks for showing.
Here I read a sentence from the book titled "Theory and Calculations of Electrical Circuits" published in 1917:
"Investigations and calculations dealing with one form of
energy only, as electromagnetic energy, or mechanical energy,
usually are relatively simple and can be carried out with very
high accuracy.Difficulties, however, arise when the calculation
involves the relation between several different forms of energy,
as electric energy and mechanical energy. While the elementary
relations between different forms of energy are relatively simple,
the calculation involving a transformation from one form of
energy to another, usually becomes so complex, that it either can
not be carried out at all, or even only approximate calculation
becomes rather laborious and at the same time gives only a low
degree of accuracy. In most calculations involving the trans-
formation between different forms of energy, it is therefore
preferable not to consider the relations between the different
forms of energy at all, but to use the law of conservation of energy
to relate the different forms of energy, which are involved."
They have not realized that magnetic energy is not created by electricity and it is a sibling that exists with any electron flow. Thus magnetic fields are not created, but they exist. And we do not "convert" magnetic energy to mechanical, but we use it as a natural force to do mechanical work. The law of energy conservation may be true, but I don't think that any "conversion" takes place in here, that's why they think that it is complex and cannot therefore be calculated.
Elias
Elias,
This is a great quote. You see, once in a while, in the old books, you'd find an HONEST author who would admit that actually measuring and calculating "energy conversions" doesn't work. I love the author's term here, that it gives "a low degree of accuracy." Then he says that invoking the "Law of Conservation" is simply used as a cover story!
CORRECT!!!
Its like saying that the REAL answer is so complicated to calculate, that everyone should forget about it and go with the IMAGINARY answer.
Its always fun to find it in print.
OK folks. Wake up! Energy Conversions are VERY elastic and COP>1 is allowed by NATURE, if you get the GEOMETRY right.
Hi Peter,
my parts are now ready. I did not post for so long, because my lathe broke down and I had to order some custom made screws to hold the plates together and that took some time. Now all the plates have some layers of varnish on them and the last layer also acts as glue and holds these plates together. Now I just need to drill a bigger hole in the X rotor middle to fit on the shaft tight. Also I need to do some lathe work to fit the rotor into the startor piece, but since my lathe is broken, I will have to get this job done by a local craftsman in his shop. This will take some time as he is always busy Here's a picture:
Thanks
Gatis
Jetijs,
This looks very good. Here are a few suggestions for your next steps.
Consider sandwiching the X rotor between two plastic wheels. This will help keep your fingers out of the assembly when it is running, and give you a greater width to mount to the shaft. This will help maintain a perfectly perpendicular mounting. A stepped flange can be left on both plastic wheels so a set screw can be used to tighten the rotor to the shaft. I do not recommend a "press fit" of the X onto the rotor. In a prototype like this, everything should be left adjustable.
Next, create a plastic frame at the back of the stator to hold the wire coil in place. As the coil is wound, it needs to be supported. I've got some systems like this. I'll try to get some pictures posted to show you what I mean.
if each of the "X" arms had its own coil, and a commutator was set to engage each arm (in turn) with the stator, there would be MASSIVE amounts of torque generated in this, all from one little "spike".
if each of the "X" arms had its own coil, and a commutator was set to engage each arm (in turn) with the stator, there would be MASSIVE amounts of torque generated in this, all from one little "spike".
Bryan,
It's true that the torque can be increased with coils on the rotor, but then you have TWO MAGNETIC FIELDS interacting with each other, creating cross inductions, and the dreaded "BACK EMF". At that point, you have a conventional motor again.
The simplest way to avoid this is to only use one magnetic field at a time. The "power-to-weight" ratio of the motor is a little lower, but the over-all efficiency is higher, and the COP is much higher.
We are purposely sacrificing the benefit of "high power in a small package" for "high power in a medium sized package" with much higher efficiency and COP.
ok, i understand that, i was thinking that the BEMF could be caught with a bifilar wind on two of the arms (opposite each other) with the back EMF being diverted the to the other two coils. then couple that with an external generator coil. (located on the opposite side of the stator coil)
but i see that the BEMF still wouldnt be stopped from travelling back through the innitial trigger wire... hmmm could diodes be used to block BEMF or deflect it backwards?
sorry, im thinking outloud. sometimes i sit and stare at my motors for hours, taking them apart, marking them with pencils, reassembling them, turning them on and off... until ideas pop into my head. i want to make 100% sure of what i intend to do before i start altering this motor... it is the only one i have. if i had money, i could test each of these ideas, but i don't
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