The Thomas Motor

[gyulasun]

Dear Ben,

I could not get the mA draw from your previous video, would you tell. 

With your saying "all things being equal" it means the current draw is also the same at the same supply voltage?

Thanks,  Gyula

[k4zep]

Dear Ben,

I could not get the mA draw from your previous video, would you tell. 

With your saying "all things being equal" it means the current draw is also the same at the same supply voltage?

Thanks,  Gyula

Hi Gyula,

Just referring to both coils are about the same, at a given voltage, both versions draw the same current due to same duty cycle from the Hall effect driver at low RPM.  The Orbo shielding and coasting by, and my motor where when the shielding occurs and the magnets push should be faster but doesn't appear to, but  I need to do some accurate RPM TEST to be sure, I'm really not doing very percision work/testing right now, will refine it as I go along.  I can switch either coil in and out of the circuit at will right now to do the speed test.......
Learning curve is steep here!  The main difference is that all things being equal, the Thomas motor due to the generator effect draws 5-10% less current at speed than the pure ORBO without a generator.  At 4000 rpm, we have about a 2 volt generator pulse being added to the motor pulse, hence the less current.

Respectfully
Ben K4ZEP

[k4zep]

   Hi TK,

Thanks for the explanation, which I have copied from above YouTube. I must disagree with you on some points.

TK:  Thanks... but no, I don't think that is quite how it works. When the coil is on, the entire toroid core becomes saturated: this means its permeability is now 1. So the field from the PM inside the core can now pass through it like air, instead of being "sucked" into the non-saturated toroid. 

BT: I agree with you here in that the magnet in my rotor and the ORBO  [/font]is sucked into the non-saturated toroid core.

TK: The Orbo in my video has no magnetic field from the coil outside the toroid, and it works by reducing[/i] the ability of the external rotor magnets to attract the toroid material itself, and this is true for both polarities. The electrical pulse to the coil is turned "on" as the magnets pass the core, not before, so that there is a reduction in attraction as the rotor magnets recede from the toroid core. This is what speeds up the rotor.

BT:  I think you realize all the speed up has already occurred due to the "sucking in or attraction" of the magnet to the core before you make the core invisible at TDC which then just coast away.  Unless the core saturation is perfect, the will be some losses in speed but that is a small point at this time.[/i]

TK:  And the polarity of the current and the polarity of the rotor magnets doesn't matter at all. It is neither an attraction nor a repulsion pulse motor, it is a unique third kind, the Core Effect motor.

BT: That is true if you are using EM's in the rotor as the core of the toroid doesn't care as it is attracted by either field and the core of the toroid doesn't generate a field that effects magnets either EM or Permanent.
I'm not sure the ORBO is a third kind of effect, it always appeared to me to be a switched reluctance motor using permanent magnets and switching the cores, hence the torque.
TK:  I think you have turned your pure Core Effect motor into a biased attraction or repulsion pulse motor by putting the PM in there.  Nothing wrong with that! 

BT:  True it is a pure attraction motor (rotor magnet to stator core attraction), up to TDC just like the ORBO,   BUT due to the core material masking the core magnet, the rotor magnet does not see that hidden core magnet.  When you turn on the coil at TDC, you unmask the magnet and in doing so you mask the core at the same time so it does not slow down the rotor (Like the ORBO) but the magnet in repulsion that just showed up then gives a second pulse to the rotor.   That is the essence of the Thomas motor and with close measurements is more efficient that the pure ORBO.   


TK:  [/i]But try it without the PM, and time it so the coil pulse starts at the closest magnet approach, not before. You might be surprised.

BT:  I did and was very surprised and flabergasted at the efficiency of the ORBO effect as you can see in my FAST ORBO video.  BUT I finally realized after posting that video that the pounding I heard in the rotor is not a power pulses in the ORBO motor but due to the fact that with just one coil, I am unloading the side forces on the rotor, hence the noise.....I initially confused that side unloading with a power pulse that not being the case.  Dual coils should fix that problem which I probably will do tomorrow.  At theoretical best, the ORBO should be ½ as efficient as the Thomas but nothing is perfect and the masking of core, unmasking of "bias" or stator magnet not being perfect, it would something less.  A quick measurement shows about a 30+ increase in efficiency in the Thomas motor vs. the pure ORBO seen in the video.

TK: Believe me, I spent years on this stuff and I have perhaps the only quantitative data on the effect of electrical currents on the magnetic attraction of ferrite toroid cores to external magnets that you will be able to find._

BT:  Right on TK, I respect your work in this arena immensely; we both have been pounding magnets for years,
In your case a lot more visible than my work and much better illustrated I might say.  ]My hat is off to you for all the work you have done.

Ben
 

[gyulasun]

Hi Ben,

Thanks for the answer and one more thing I would be curious to know is that how the input current changes when you try to slow the rotor a little, i.e. apply some mechanical load onto the rotor. I think just a little increase may happen in the current draw.

I think the Thomas setup should certainly give more torque than the Orbo setup due to the extra repel force received after the TDC, using the same conditions for both setups.  Some finer details here involve considering core saturation: in the Thomas setup it starts the moment you position the small magnet to the inside of the toroid core, my earlier tests using an L meter clearly showed this when was playing separately with some ferrite toroid cores and magnets attached to it. In the Orbo setup, saturation begins when the magnet(s) start to attract to the core and of course this is true for the Thomas setup too. This saturation can be an advantage in bringing down the input power demand to fully saturate the core, and this may involve choosing the strength of the magnet inside the toroid core wisely. I believe the 'wise' choice means here just balancing the repel force between the rotor magnet at or just after TDC and the inner stator magnet to zero via the thickness of the toroid core, this could be adjusted simply by using fine spacers as sandwiches between toroid core inner wall and the inner magnet.

Thanks for showing this interesting setup. 

Gyula

[k4zep]

Hi Ben,

Thanks for the answer and one more thing I would be curious to know is that how the input current changes when you try to slow the rotor a little, i.e. apply some mechanical load onto the rotor. I think just a little increase may happen in the current draw.  In the ORBO, no change in current if ratio of off to on stays the same, in the THOMAS, current increases as you slow it due to less generator effect.  At ZERO RPM, Current in both ORBO and THOMAS are the same.

I think the Thomas setup should certainly give more torque than the Orbo setup due to the extra repel force received after the TDC, using the same conditions for both setups.

IT does!

Some finer details here involve considering core saturation: in the Thomas setup it starts the moment you position the small magnet to the inside of the toroid core, my earlier tests using an L meter clearly showed this when was playing separately with some ferrite toroid cores and magnets attached to it.

ABsolutely!

In the Orbo setup, saturation begins when the magnet(s) start to attract to the core and of course this is true for the Thomas setup too.

Yes, more so.

This saturation can be an advantage in bringing down the input power demand to fully saturate the core, and this may involve choosing the strength of the magnet inside the toroid core wisely.

Correct, there are a bunch of variables here that could be optimized that I have not done!

I believe the 'wise' choice means here just balancing the repel force between the rotor magnet at or just after TDC and the inner stator magnet to zero via the thickness of the toroid core, this could be adjusted simply by using fine spacers as sandwiches between toroid core inner wall and the inner magnet.

If you mean when the core magnet is off, you are correct.  Core ON, permeability near to "1" as you can get it to allow the field to punch/repulse the rotor magnet after TDC.
You have a good handle on this I believe!!!

Ben


Thanks for showing this interesting setup. 

Gyula