UFO politics Keeps his word 12-12 12 Let the games begin.......

[ramset]

Perhaps some more insight into the "effect" from UFO.


If You do not have clear the Symmetrical Basic Concepts...You can not understand Asymmetry, my friend...That is why I dedicated just one video to show how Symmetry works [SYMMETRY OF DARKNESS]...looking at it from their Static-Symmetrical Virtual Magnetic Fields at their Rotor-Armatures (Watch it at Video Time 3:10 )...and that "Side of Symmetry"...You WILL NOT learn it at ANY Engineering or Technical Schools...That is where the "Key" to unveil the Big Difference between the Two Systems exists.

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[picowatt]

The one thing you wont see PW is ufo doing the same test he did on his moded motor with an of the shelf motor.
I have done the test ,his way and the correct way.
Useing his method,my tired old 24 volt motor had an efficiency of 130% plus.
Useing the correct method,i came within 4% of the manufacture's spec for that motor-about 74% efficient.
Now useing UFO's own measurments,his motor(when calculated correctly) is about 70.4% efficient.

So im guessing he is now going for the land speed record-or something like that.
I think i would just go and buy one of these motor's if i wanted high RPM-and only $480.00 here in OZ.
http://www.400hertz.net/Products/ME-C500-75WC.htm

In reguards to the motor speed controller,if it is going to be under 20khz on the frequency-would it not be better to use IGBT's?
They handle current much better than a mosfet,and are what most HF tig welders use today.
My little caddy is happy at 140 amps all day,or 170 amps at 60% duty cycle.
Infact it would be quite easy to convert one of these to a motor speed controller.

Maybe UFO is going for speed now to keep the interest there?

Tinman,

Yes, IGBT's could be used, but device dissipation can be made lower for MOSFETs.  IGBT's typically have a saturation voltage of 2 volts or greater, so 100 amps passing thru a 2V Vce IGBT would dissipate 200 watts of heat.  A MOSFET with a .01ohm RDSon would only have a 1 volt drop across it when fully on and only dissipate 100 watts of heat under the same conditions.  Paralleling MOSFET's reduces the total on resistance, hence their Vdrop, hence total dissipation, whereas paralleling IGBT's does not decrease dissipation (Vce remains the same) but does make all the devices share the total dissipation.   

For high voltage applications, however, the IGBT can be just the ticket, and can be more robust in some applications.  Also, IGBT's are available with and without a freewheel diode across the CE junction and can be useful where the MOSFET's parasitic body diode is not desired.

Most inverter type TIG/MIG boxes use an offline switcher (ie, switch the rectified AC line) to drive a transformer, so the IGBT or similar switching device does not see the full output current due to the  primary/secondary xfmr ratio.  By using HF switching (as in the 20KHz you mention), the transformer can be very small and lightweight compared to a similarly rated 50/60Hz xfmr.

I believe you said UFO emailed you regarding his Prony tests and your assertions relating to his errors, have you heard from him since you performed your tests and made your video?  You are probably correct regarding not seeing him do a comparison Prony test on a non-modified motor.

As for his desire to operate at higher RPM, possibly he is just raising the bar to make testing more difficult, with high speed and complex drive circuits now required to show OU.  He is now discussing a four phase drive circuit, and I don't really see why.  He is discussing asyncronous operation, and originally, I thought he wanted to only power a winding briefly as commutation ocurred and be synchronous to that commutation.  At the higher RPM, that would require pretty fast switching.

Again, if his concept is sound, one has to wonder why all this could not have been done with a smaller modified motor with lower current requirements to make testing and drive circuits much easier for a proof of concept (and less costly for replicators).

PW

 

[picowatt]

I just read UFO's response to Ian's question regarding the need for such high RPM.

Are people over there really buying that?

Not sure what his "pounds" measurement refers to, but, and please correct me if I am wrong, 15 foot pounds at 3600 RPM should drive his AC gen at or near full load.

15 lb ft X 3600/5252= 10.28 HP

PW

Added:

If the gen is only 60% efficient, then closer to or just over 20 foot pounds at 3600 RPM would be needed.

[TinselKoala]

And if UFO is still throwing wraps, or nearly so ....even with his costly epoxy and his winding skills.... how much less successful will be the less-experienced rewinders in the project? One builder's photo shows some very loose wraps indeed.....

But the mosfets from the electric bike, IRFB4310, have a typical Rdss of 0.0056 Ohm... supposedly the lowest available in a TO-220 device. Clearly they are fast enough for FM/PWM motor controllers. I wonder just what the sequence of events was that caused the bike controller to fail.


I really like these high-powered "inside-out" brushless motor designs, where you never have to worry about throwing wraps... because the armature is motionless and the "stator" with magnets rotates around the outside of it. Other high-power brushless motors are conventionally built with stationary coils wound like field coils in the case and "armatures" that are just magnets on the shaft. The controllers for these brushless DC motors can do just about anything, from running in either direction, to braking, to regeneration, and many even have variable timing to compensate for varying loads and speeds.

[MileHigh]

The funny thing is that in certain realms there is clearly an attitude that the "asymmetric" winding system is superior than "conventional 'symmetric'" winding system.   Yet, it still has never been proven with any data.

Here is a great link for deep motor contemplation and prime mover enlightenment:

https://www.google.ca/search?q=electric+motor+performance+curve&hl=en&safe=off&tbo=u&tbm=isch&source=univ&sa=X&ei=osDwUN2fMrSs0AGosIGQBA&ved=0CDkQsAQ&biw=1204&bih=609

Keep your hands in your pockets and look at the squiggly lines.