Pulse Motors- Your building them wrong.

[Nali2001]

Today's post, https://overunity.com/19069/holcomb-energy-systemsbreakthrough-technology-to-the-world/msg581931/#msg581931, reply #3079, second link, included the graphics attached. Similar to what tinman is developing. Just found it interesting, perhaps useful for some.

Also, when the torque is from a PM and an electromagnet at a constant excitation, result can be considered cogging. Note graphs and discussion on pages 3&4 in attached PDF.
bi

Hmm yeah dunno. This has been tried many times including by me. In static cases yes it does increase the holding torque by 3.5 times which is easy to test and is real. But try using that in a rotating reluctance type motor and you will find that adding the magnets does nothing. I made models where you can run the motor without magnets and later drop them in while running it and is does nothing. This is because in such a reluctance motor the gap between stater and rotor finger is just too large and too much of a resistance for the magnets to want to 'switch' out of their close looped core structure, over to the airgapped rotor piece. The gap is of course getting less and less when the alignment increases but by the time the gaps are so close that the magnet will switch over, the forces have become tangential and add nothing to the rotation. 

[Nali2001]

Ah, but this is unlike any conventional motor, as the magnet does not move, and does not induce any back EMF in the coil.
The coil is already induced with the static magnetic field of the PM, and when the coil is switched on, it is producing the very same field that is already induced within it from the PM, not the opposite field like in the pulse motor example.

I will be doing a video on this soon.
Brad

Hi Brad, fair enough but I would like to add that anything that can dynamically change the inductance of a coil in any way will cause a loading effect. That is also the reason why reluctance motors still have loading effects despite 'no magnet' is influencing the coil, since the making and the braking of the core structure heavily influences the inductance the coil. If you put an inductance meter on the coil and you rotate the wheel and the inductance changed then a loading effect will manifest.

Also to me when you fire your coil it needs to repel the field from the magnet right? If so that means it needs to completely reverse the field that is statically put in there by the stationary magnet if not then it would be attracting it. But since you repel it, it is the opposite polarity and this reversion of field will also cost you since in order for the repelling field you want to manifest you first have the invest the energy to 'drive the field of the magnet out' and flip the polarity so that they repel.

All in all I have seen too many threads go under by people criticizing things, I do not want that to happen so I will build it as instructed!

[tinman]

Hi Brad, fair enough but I would like to add that anything that can dynamically change the inductance of a coil in any way will cause a loading effect. That is also the reason why reluctance motors still have loading effects despite 'no magnet' is influencing the coil, since the making and the braking of the core structure heavily influences the inductance the coil. If you put an inductance meter on the coil and you rotate the wheel and the inductance changed then a loading effect will manifest.

Also to me when you fire your coil it needs to repel the field from the magnet right? If so that means it needs to completely reverse the field that is statically put in there by the stationary magnet if not then it would be attracting it. But since you repel it, it is the opposite polarity and this reversion of field will also cost you since in order for the repelling field you want to manifest you first have the invest the energy to 'drive the field of the magnet out' and flip the polarity so that they repel.

All in all I have seen too many threads go under by people criticizing things, I do not want that to happen so I will build it as instructed!

I welcome any input, and when it comes to this motor, and i understand that most will be thinking in conventional terms.

I will try to explain as best i can what happens in this situation.
I took the time to run my test motor with and with out the PM-nothing else was changed, and took scope shots to show the change.

!please note that this is a different coil i am trying out, to that of the one i used in the static test. Larger wire with less turns-to get the voltage down.!

The first thing you will see, is how quickly the coil reaches it's peak current of 2 amps with the magnet in place. (the CVR is 1 ohm)
When the coil is switched on, an apposing field starts to build in the coil. This causes a rapid exponential magnetic field expansion through the windings of the coil, which in turn, causes a rapid flow of current through the coil. This is why the coil can reach it's peak current of 2 amps faster than would be normal. You do not see this in the scope shot of the motor running without the magnet.

The next thing you see, is a rapid drop in voltage across the coil, right as the current hits its peak.
This is the point where the combined magnetic fields in the core, see a rapid decrease as the fields flip from the coil core, and latch onto the torque plate.
At the same time, the coils inductance is increasing, which is why the current flatlines at 2 amps, and the voltage remains low.
As you can see, the voltage drops from 6v slowly for 2ms, and drops rapidly to below 4v for the duration of max current flow.
You will also see this does not happen when the motor is run without the PM, and the current rise time is much greater.

You will also see that when the PM is removed, the motor consumes more power, the current rises slower and higher, and even after 5 minutes running, could not reach as high rpm, as can be seen by the time constant on the scope shots

The inductive kickback energy is greater for the motor running without the magnet, and that is because both the current through the coil, and the voltage across the coil was higher, and so the coil had more stored energy to release.

It is interesting that most say PM's cant do useful work, as the only thing we did, was remove the PM, and lost a lot of efficiency in the motor.

So all in all, the motor without the PM consumes more power for less rpm and torque.
Seems like the PM is doing useful work to me, as that is the only thing we changed between the two runs.


Brad

[Nali2001]

I welcome any input, and when it comes to this motor, and i understand that most will be thinking in conventional terms.

I will try to explain as best i can what happens in this situation.
I took the time to run my test motor with and with out the PM-nothing else was changed, and took scope shots to show the change.

!please note that this is a different coil i am trying out, to that of the one i used in the static test. Larger wire with less turns-to get the voltage down.!

The first thing you will see, is how quickly the coil reaches it's peak current of 2 amps with the magnet in place. (the CVR is 1 ohm)
When the coil is switched on, an apposing field starts to build in the coil. This causes a rapid exponential magnetic field expansion through the windings of the coil, which in turn, causes a rapid flow of current through the coil. This is why the coil can reach it's peak current of 2 amps faster than would be normal. You do not see this in the scope shot of the motor running without the magnet.

The next thing you see, is a rapid drop in voltage across the coil, right as the current hits its peak.
This is the point where the combined magnetic fields in the core, see a rapid decrease as the fields flip from the coil core, and latch onto the torque plate.
At the same time, the coils inductance is increasing, which is why the current flatlines at 2 amps, and the voltage remains low.
As you can see, the voltage drops from 6v slowly for 2ms, and drops rapidly to below 4v for the duration of max current flow.
You will also see this does not happen when the motor is run without the PM, and the current rise time is much greater.

You will also see that when the PM is removed, the motor consumes more power, the current rises slower and higher, and even after 5 minutes running, could not reach as high rpm, as can be seen by the time constant on the scope shots

The inductive kickback energy is greater for the motor running without the magnet, and that is because both the current through the coil, and the voltage across the coil was higher, and so the coil had more stored energy to release.

It is interesting that most say PM's cant do useful work, as the only thing we did, was remove the PM, and lost a lot of efficiency in the motor.

So all in all, the motor without the PM consumes more power for less rpm and torque.
Seems like the PM is doing useful work to me, as that is the only thing we changed between the two runs.


Brad

Hi Brad, from what I see, I agree that running it your way indeed is more efficient than the conventional way.
You sure that the voltage drop at 2amp is not caused by the 2 amp max control on your power supply? And that you did not had the 2amp max set on the 'without magnet' run? Just wondering.
Do you have a cap on the flyback capture circuit? What is clamping its voltage?
Kind regards,
Steven

[Kapalek]

Hi,
I am not sure what is the radius of this rotor but if you could check the NewtonOmeter (grams of pull x radius) value and then estimate at what rotational speed this pulse still has its kick power (about 10Hz maybe?).
So power should be (rotational speed) x (grams pull x radius) = (mech power)
(400 rpm) x (300g x 5cm) = mech power rotor. (Just an example of calculation idea)
Question is what would be pulse duration of 2A@10V ?