Electric Motor Secrets

[lighty]

Today is the one year anniversary of this forum.

How fast time flies!!!

[Aaron]

1 year anniversary!

Hi Peter,

Very awesome!

[SkyWatcher]

No or reduced back emf possibility with magnets

Hello, nice to meet all of you. I have read all posts here and fully understand Peters motor and have seen his dvd. I've also built many motors including one like Peters original, only with 4 rotor,6 stator for 3 phase, of course since it wasnt machined and i was just testing the principle torque was rather low.
What brings me to post here and even though its not strictly attracting a piece of ferro metal is the adams motor odd-even geometry of which im not sure exactly how he had it wired other than series coils, i noticed a similarity between his and butch lafontes back emf cancelling idea. because when one magnet approaches opposite coil which is out of phase to other magnet, the other magnet is leaving the coil. Approaching magnet is wired attract mode, one leaving wired repel mode would also cancel or reduce much of the back emf. tests show with dmm & analog amp meter that little current gets through. the design im testing is 6 stator,7 rotor magnet w/ 2 rotors sandwiching axially the stator plate. Tests show good torque with only 1 phase so far and it leaps to full speed at 24v,1.5A no load. 2.2A full hand grip on shaft. I praise the work and interest you folks have in this field because energy is everything and will have our unlimited sources soon enough. I hope my thoughts are of any help, peace.

[theremart]

Happy 1 year birthday



This forum has been awesome! Open free creative imaginative thinking sharing our success with cheers and failures alike, learning and moving forward.

Big thank you to all who have made this possible.

[Jetijs]

Hello all.
I finally got my new rotor made. Everything looked fine till I tested the balance. I was shocked when it turned out that the new rotor has the same disbalance as the previous one. This could not be a coincidance. I looked at my CAD drawings again and found that everything is ok there, everything is symetrical. Then I took a closer look on the rotor silicon steel plates and found out that the middle shaft hole is a tinny little bit (about 0.3mm) offcenter to one side. This makes the disbalance. I talked to the laser guy about this and he can't figure out how this could happen. Probably the CAD drawing was changed somehow ehrn the laser cutter software converted it according to its needs. Anyway, I had to order some counterweight plates that I could attach to the shaft to get the rotor balanced. Unfortunatelly I was out of silicon steel so I had them made out of stainless steel in different thicknesses. Here is a picture:







You can see how big the disbalance was by looking at the counterweight I had to put on the shaft.

Anyway, now the rotor is ready, well balanced and the airgap is 0.08mm
I made a quick test with a comutator wheel with one 60 degree gap on each side, just to see if and how it will work. I got 2400 RPM on the first try
That is at 12V. There is almost no vibration when the motor runs and everything seems fine. Now I need to change the driving circuit so that it can operate at 24V and make some aluminum heatsinks for the MOSFETs.
I will upload a small video on youtube later.
Thanks,
Jetijs

[Peter Lindemann]

Awesome!!!!

Jetijs,

Your patience and persistence in solving each and every problem that has arisen are an inspiration to everyone on this forum. Your studies of how wide the power impulse can be to create the largest energy return for your design are a model of good engineering practice, and I thank Lighty for guiding you through that phase of the work. Your continued examination of the rotor imbalance situation has lead to the solution and a highly balanced rotor with a tight air-gap. Again, only persistence and careful observation, coupled with practical deduction and hard work have lead to the solution.

You are an inspiration to us all!

Your next set of tests should be quite interesting!

Peter

[Jetijs]

Thank you Peter
Your words are encouraging

Here is a video of how my motor works at about 12v. The RPMs are about 2400.

YouTube - Lindemann attraction motor V2.0 video 5

After this test I made the needed changes in the drive circuit so that I can run the motor on higher voltages. When the changes were made, I first connected the motor so that only one phase was working. The power supply was set to about 12v when I switched it on. The motor started to spin fast. Then I increased the voltage slowly till it reached 20V, the RPM's were about 3000 and that is on one phase only Then I connected also the other phase and turned the power supply ON. Now the motor spinned even faster at about 4300 RPM. Here is a video of this test:

YouTube - Lindemann attraction motor V2.0 video 6

After that I increased the voltage up to 24V and the RPMs now reached 5300
I also noticed that at 12v the amp draw was at about 2.2 or so, but as I increased the voltage, the RPMs increased but the current draw remained mostly the same, I think that this is because as the speed increases, the impulse duration becomes smaller and this makes a better recovery. The output in all these tests was connected to the capacitor on the input section. I also noticed that the shaft became warm after these short tests, I don't know so far if this is because the bearings heating up and transferring some of the heat to the shaft or the silicon steel laminations heat up because of the eddy currents.

Next I will try to pulse the optotrigger LEDs and see how it works
Thanks,
Jetijs

[Peter Lindemann]

Same Behavior

Thank you Peter
Your words are encouraging

Here is a video of how my motor works at about 12v. The RPMs are about 2400.

YouTube - Lindemann attraction motor V2.0 video 5

After this test I made the needed changes in the drive circuit so that I can run the motor on higher voltages. When the changes were made, I first connected the motor so that only one phase was working. The power supply was set to about 12v when I switched it on. The motor started to spin fast. Then I increased the voltage slowly till it reached 20V, the RPM's were about 3000 and that is on one phase only Then I connected also the other phase and turned the power supply ON. Now the motor spinned even faster at about 4300 RPM. Here is a video of this test:

YouTube - Lindemann attraction motor V2.0 video 6

After that I increased the voltage up to 24V and the RPMs now reached 5300
I also noticed that at 12v the amp draw was at about 2.2 or so, but as I increased the voltage, the RPMs increased but the current draw remained mostly the same, I think that this is because as the speed increases, the impulse duration becomes smaller and this makes a better recovery. The output in all these tests was connected to the capacitor on the input section. I also noticed that the shaft became warm after these short tests, I don't know so far if this is because the bearings heating up and transferring some of the heat to the shaft or the silicon steel laminations heat up because of the eddy currents.

Next I will try to pulse the optotrigger LEDs and see how it works
Thanks,
Jetijs

Jetijs,

Yes, I have seen the same behavior in my unit here. The voltage rises, the speed rises, but the input current stays the same.

Great work!!

Peter

[Grace]

For Peter!

Just wanted to wish You and your amazing work here a Happy Belated Anniversary! Your work is Love and Supported! You are Blessed!!

[elias]

Enjoying!

Hi Jetijs,

I enjoy seeing your motor in operation. Your motor should have a great amount of torque to it. Have you tried running it at around 40v? It should Rock! I am looking forward to see the perfection of your motor. Thanks!

Elias

[Jetijs]

Elias,
my logic circuit positive voltage regulator only allows me to go as high as 35V max. But at this point I don't think that I will need to increase the speed more. Now I need to pulse the optortigger LEDs and find the correct frequency and duty cycle at which I can get the best recovery. Then we will measure the efficiency of this motor. And yes, the motor has a considerable torque, I mean I can't really stop it by hand. At the same time I also have a small induction motor that is rated 120W and I can easily stop that motor with hand, my motor currently consumes about 50W at 24V . I just like how the motor gets at its full speed almost immediately
BTW, thank you, Grace, for the blessings

Thanks,
Jetijs

[Peter Lindemann]

Further Refinements

Elias,
my logic circuit positive voltage regulator only allows me to go as high as 35V max. But at this point I don't think that I will need to increase the speed more. Now I need to pulse theoptortigger LEDs and find the correct frequency and duty cycle at which I can get the best recovery. Then we will measure the efficiency of this motor. And yes, the motor has a considerable torque, I mean I can't really stop it by hand. At the same time I also have a small induction motor that is rated 120W and I can easily stop that motor with hand, my motor currently consumes about 50W at 24V . I just like how the motor gets at its full speed almost immediately
BTW, thank you, Grace, for the blessings

Thanks,
Jetijs

Jetijs,

I looked at your latest video. Awesome!!! The fact that the motor jumps to top speed very quickly is also an indicator of its torque production.

Before you change anything else, you may want to build a dynamometer, like I show at the beginning of my DVD, to start measuring the mechanical energy produced by the motor. You are at the point where looking only at the electrical efficiency of the motor is not enough.

The energy economy of the motor is as follows. It takes a certain amount of electricity to produce the magnetic fields in the stator pieces. Once running, the machine produces TWO BY-PRODUCTS from these magnetic fields. The first product, is the motion of the iron rotor coming into alignment with the stator pieces, and the second product is the electrical energy given back when the magnetic fields collapse. Individually, each of these energy products is "under-unity" in the classical sense, but their COMBINED VALUE can become greater than the original amount of energy expended, due to the geometry and timing of the systems.

Also, if you would please publish your current wiring schematic, I would like to see that at this point.

Before you start flashing the LEDs, you may want to look at the FET timing on your scope as the motor runs. At those speeds, you may be within the optimal window of operation already. If not, you can still run the stator coils in PARALLEL (each coil with its own FET), to reduce the inductance of the coils and reduce the rise-time even further. So, there are still a number of options for "tuning the motor up" at this point.

I sure wish I was in Latvia, right about now.

Great work!

Peter

PS. Thank you, Grace! Your heart-felt support has been a blessing, right from the start!

[Jetijs]

Peter,
Here is the circuit I am using now:
http://www.emuprim.lv/bildez/images/...ma10%20(1).GIF
The blue lines represent the recovery part, I think I drew everything right.
I will do the mechanical energy measurements. I already have two small electronic scales that I can use. I will make the brake wheel out of acrylic. I just need to figure out how to attach the wheel to the shaft.
Thanks,
Jetijs

[lighty]

If not, you can still run the stator coils in PARALLEL (each coil with its own FET), to reduce the inductance of the coils and reduce the rise-time even further.

@Peter

I used UCC3732x drivers extensively for the last few years and they can each easily drive two IRFP450 (or even more but with some modifications). I also sent adequate number of MOSFETs to Jetijs so he has enough MOSFETs to try driving each coil separately. He may have to change gate resistor value (if needed) but in this particular circuit I believe it will be enough to add another MOSFET in parallel with the existing one without changing values of the components.



@Jetijs

Good work indeed. I love the elegant way of solving your disbalance problem. I thought you would go for a new rotor plates but this is faster and cheaper (and more elegant). Congratulations!

Also, if you need help setting up the parallel configuration contact me the usual way.

[Jetijs]

Peter,
I watched your video about the dynamo meter again and a question arised. Why do we need the wheel? Why can't we just load the shaft with that leather strip? I mean if we know the shaft diameter, we can calculate the circumference. If my shaft is 8mm in diameter then the circumference would be 2 x phi x R, or 2X3.14X4=25.12mm. Right? and we can easily convert this to foots.
Of course I will build the wheel, but it is not as easy as I thought and it will take more time.


Jetijs