Can anyone verify cogging-torque neutralization ?

[citfta]

Hi again Dave,


I just realized I need to clarify my previous post.  AC motors that have brushes like those used in vacuum cleaners and electric hand drills etc. are not speed controlled by the frequency of the AC.  They are actually basically universal motors that will run on DC or AC.  So one of those type motors might be able to run directly from the output of the generator as long as the generator frequency is not too high.  An AC frequency of more than 400 hertz or so will cause them to heat up. But if you try to run the motor directly off the generator output you will need some kind of control between the output and the motor to prevent a possible run away condition if the output is more than the motor needs to maintain a certain speed.


Take care,
Carroll

[Dbowling]

Hey Carroll,
Thanks for the info. I don't have a lot of faith in his ability to get it running on AC either, although he is working with an electrical engineer from the independent testing lab where we have taken the generator for testing. The guy is helping him with wiring and such, so maybe they can figure it out. He DOES have the attached device which according to him, controls AC all the way down to 0 output, but from what I can tell, it STILL has to have 120 volt input in the 50-60 Hz range, so I'm not sure what GOOD that does him.


I am pinning MY hopes on the 110 volt DC treadmill motor I am taking with me. I figure if we rectify the output of the AC coil we will get a specific DC voltage if we are running the generator at a specific RPM. Since there is no speed up or slow down under load, the RPM is constant so the voltage output should be too. One coil pair may not have enough amps to run the motor, but two or three will, which still leaves me with three coil pair to use as output to load, and that will light a 300 watt light to full brightness with each coil pair.


My intention is to connect the pictured transformer to wall output, and rectify the output of the transformer to DC. Then run the DC motor with it and use the adjustment to get the motor up to the RPM we want. I can then measure the AC output out of the transformer and compare it to the AC output from a coil pair. If the output from a coil pair is LOWER, I am screwed, unless I rewind the coil with longer strands or up the RPM. If it is HIGHER, and I truly believe it WILL BE, then I reduce the length of the wire on the coil until the AC output from the coil matches the AC output from the wall. If I have to SIGNIFICANTLY reduce the length of the wire, I could rewind the coil with more strands to up the amp output, but for NOW I will be happy to just see it self run. I hope this all makes sense. I know, for instance, that dropping the wire length from 1000 feet to 800 feet brought the coil output down from 130 volts to 120 volts. That's MY plan for Monday, but WE BOTH KNOW I AM NO WHIZ WHEN IT COMES TO ELECTRONICS. I am flying by the seat of my pants most times, and depending on guys like you and Matt to bail me out when stuff goes up in smoke.


I have pretty much told my machinist he can keep this version of the machine in his shop, since he is in the process of building ANOTHER one that addresses all the mistakes we made on this one. That will be the 17th version of the generator we have built. If the ferrite cores prove out, this machine will be a waste of time and money anyway because those coils (if successful) that will change the entire design of the machine, but I won't know that until I get mine up and running with the cores I just made and see if ferrite will speed up under load. He doesn't like changes. He has a version that outputs more than it takes to run, and he is happy with that and wants to stick with what he has. I, on the other hand, am all about longer, faster, stronger, more output, more economy of motion, etc. I drive the guy crazy always wanting to make changes.


I am presenting the generator at the Energy Science and Technology Conference in July, so by then I want to have the ferrite thing figured out, and have the bigger machine self running. If all else fails, I can simply show input vs output. That should raise a few eyebrows, but a self runner would be a lot more fun, and that is the goal. I have an electrical engineer friend who is also a physicist who has agreed to help design whatever I need to get it to self run, and we have time before July. I may end up bringing three versions of the generator to the conference just to show. I realize no one believes in this thing, but I have seen inputs and outputs. I KNOW it only takes 288 watts to run that MY1020 Razor scooter motor at 2800 RPM, and by fine tuning the machine, the machinist has gotten it down to less than that. Exactly HOW low, I won't know until Monday. Regardless of that, there is no magnetic drag, and there is no slow down under load from Lenz. Each coil puts out 130 volts at 1.5 amps. He is currently powering five 300 watt bulbs, not to full brightness because it is only running at 1140 RPM for some reason. Now those output numbers are from when I had six 2" x 1/4" magnets on the rotor and the new machine has twelve 1" x 1/2 or 3/4" magnets on the rotor. I honestly don't remember which. It has been too long since we built it and the machinist has had it in his shop for MONTHS. But I DO know that the overall output of the machine went UP when we went to more magnets, because the MASS of the magnets was about the same as the magnets on the original machine, and there were twice as many of them. So we will see on Monday, and I will be taking video of everything.


The only remaining issue for long term running with iron cores is the heat, but by extending the cores out the back of the coils and immersing them in a network of PVC pipe filled with water, I have proven (to myself at least) that this is an issue that has solutions. Ferrite cores may also address that issue, but all that is for another day when I FINALLY have my house remodeled to sell.

[Dbowling]

Hey Carroll,
I don't think a drill motor would have the RPM I need, but I am looking around for a Universal motor in case the DC motor I have doesn't work for some reason.
And I may call you Monday if I get into trouble. Well, more trouble than I am ALREADY in. LOL

[citfta]

Hey Dave,


The easiest way to make your system a self runner is to use the variable transformer you have and connect the input to one or two of your output coils and the output to a 50 amp or so bridge rectifier and the output from the bridge rectifier to your scooter motor.  You already know you can adjust the voltage to the scooter motor to get the speed and power you need.  You can adjust the output of your variable transformer to get the voltage you need for the scooter motor.  That is probably the simplest way to go.  The problem with the universal motors is they are almost always a part of some kind of appliance.  You can rarely find them as stand alone components.  This makes them difficult to adapt for use in something else.  So that is why I suggested just staying with the scooter motor.


If you want to call anytime Monday that is OK with me.  We can probably do a Skype call if I can remember how to do that.  I may have to go out of town though.  I just remembered that my last uncle (Dad's brother) passed away last night.  He lived back in KY so I will be going back there for the funeral.  But my phone will be with me so we can still get together by phone if you need to.  I don't know the funeral arrangements yet so don't know when I will be going.


Take care,
Carroll