Hi everyone,
I'm starting this topic as some of you may be interested in this video demo I made for a topic presently going on at the Energetic Forum http://www.energeticforum.com/renewable-energy/20366-your-basic-coil.html (http://www.energeticforum.com/renewable-energy/20366-your-basic-coil.html) on what causes a Generator Coil to Accelerate Under Load. I know this been discuss at this forum many times and I don't care to discuss it further or even at the EF topic for that matter.
This is mostly an information topic which I will moderate, so be careful what you post if you chose to do so.
This effect is far from being new as I found out from user Erfinder that The Great Nikola Tesla had developed this in 1894 and was granted a patent (see attached).
The effect can be tuned with the core distance between the magnet rotor and the coils.
A few years back when I finally understood the AUL effect was not just about the coil geometry but also had to do with the core length.
Since then, I've been wondering what's going on in the core that is assisting this effect.
So I built a test device to further study it with all the rest of the stuff I'm doing ::) , LOL
Here's the link to the video demo: https://www.youtube.com/watch?v=cr3x0xTqM_k (https://www.youtube.com/watch?v=cr3x0xTqM_k)
The coil used in the demo has 5.3 Ohms dc resistance and between 26 to 27mH at any point on the 1/2" round rod core.
Luc
Update,
most who have been experiencing this AUL (acceleration under load) effect may of noticed it's easier to achieve it with a higher impedance coil (more turns) then a low impedance coil and also using higher rotor rpm = higher frequencies.
Many, including myself (2 years ago) would of thought the coils Inductance was part of the effect seeing it happened with higher impedance coils.
I have now confirm (to myself anyways) that the effect is not based on the coils Inductance by testing the super low impedance coil I showed in my video.
It's inductance is 16uH with a resistance that's so low, it's unmeasurable.
With this special wounding geometry coil I can achieve AUL with the magnet rotor as low as 35Hz which is a new record for me.
The great thing about being able to achieve AUL at a lower frequency is, drastic reduction of core losses caused by eddy currents and hysteresis.
Just thought I would share my new findings
Luc
Very interesting video Luc. Thank you kindly for sharing it with us.
So what we think is happening is the magnetic field is propagating through the core material similar to dominoes falling and like any wave, there are nodes and valleys. When the coil is positioned in the proper location it creates a reflection back to the prime mover that is exactly in tune with its rotation.
This makes me think the coil and core is behaving somewhat like a transmission line and with a transmission line we also have impedance that must be matched. Gets a little confusing because we have magnetic properties as well as electrical properties both in play here.
Your demonstration certainly provides a lot of food for thought. Thanks again.
Quote from: gotoluc on January 15, 2016, 11:08:32 PM
So I built a test device to further study it with all the rest of the stuff I'm doing ::) , LOL
Here's the link to the video demo: https://www.youtube.com/watch?v=cr3x0xTqM_k (https://www.youtube.com/watch?v=cr3x0xTqM_k)
That's a pretty good experiment.
Note that the conductive rod core constitutes a shorted 1-turn coil that always brakes the rotor.
It is possible for the slidable multiturn coil to interfere with this braking action.
So for a clean experiment you'd need to use a non-conductive core.
Note that "non-conductive" does
not mean "without magnetic hysteresis", which is an unrelated property of a material.
P.S.
Do you have a non-inductive low ohm resistor to use as an input current sensor instead of the clamp-on current sensor ?
For every type of coil there is an ideal point where you can get acceleration under load. It can be done without the additional coil.
The best way is to maintain the same speed under load while the power generated is of a considerable amount.
This can be done using a small amount of power from an external source providing voltage while the coil itself will add the amperage resulting a magnification process.
This process can also be used in a solid state configuration.
The patent office .?
Never give a man a stick to beat you with !
Respectfully
Chet
QuoteThis can be done using a small amount of power from an external source providing voltage while the coil itself will add the amperage resulting a magnification process.
It simply doesn't work like that and there is no "magnification process" taking place. Plus the language being used does not make sense, coils don't "add amperage."
Every one of these setups needs to be evaluated on a case by case basis. There is no generic "advice" on how to see a rotor increase in speed when the configuration is changed.
And "configuration is changed" is the key phrase. I make a change to my system by adding a load. Therefore there are two configurations to analyze, without the load and with the load. All off the voltages and currents need to be measured and a complete power audit has to be done for each configuration, never forgetting to account for the waste heat. Countless times experimenters have been thrown off and they confuse "increased output" for what is really less waste heat.
If you really want to understand a setup then you should construct a
timing diagram with as much information as possible incorporated in the timing diagram. All of the answers explaining the how and why and when of the setup are revealed in the timing diagram.
MH
Sorry, but I think you are beginning to wander far off course. What possible connection does a composite video signal have to do with a coil causing or allowing a rotor to accelerate under a load?
Carroll
It's just an example of a timing diagram for illustrative purposes.
I found a more interesting timing diagram showing an operating mode for a 555 timer. A picture is worth a thousand words and the timing diagram for the 555 timer in conjunction with a schematic and a text description provides the reader with a complete understanding of what is going on. A pulse motor is typically more complicated than a 555 timer circuit and therefore you need a timing diagram, schematic, and text description to understand what is going on.
@gotoluc
Son of a gun. I just saw this thread and your video. hahahahaha Life is just so great sometimes when things just start falling into place.
Here is what I think needs to done next.
To simplify things, since the coil is showing an AC sine wave maybe consider just using a small rheostat and a bulb instead of your resistors. That will give you infinite load adjustment.
What you really want to know here is what is going on in that sliding coil. Taking a differential reading is like calling New York, then calling Los Angeles and then saying "I know what's happening in the USA". Very deceiving.
What we need to see is what is happening on each added layer of that coil. We think that the core to coil impress is making "electrons flow" (using regular terms here for now) through all of that coil which is a multi layer, mag wire type with tight turns and "no space between layers". I have just posted on this and such a situation I see know as producing what I call Coil Bypass. I think that is what you are seeing there.
If you can drill small holes on one side of that plastic coil spool up to the end turns of the coil and just send one pointy probe and scope it and see the difference from one layer or a few layers to the next few layers, this will give you so much more information then you ever had. hahaha
The other experiment is you take two lengths of identical wire and identical spools. You wind one length on one spool as usual, layer after layer, tight. The other you wind same way but you add a spacer between layers so the layers cannot touch each other. Then you do comparison studies of these two and this will again tell you a lot more then you knew before. Remember old transformers with paper between layers. WHY do we not see that anymore? Was is to efficient? hahaha
The point is this. There is technical process and there is reality process. We technically think the impress is "flowing" through that whole coil. But the coil really has three parts. First layer, mid layers and outer layer. The the coil has first layer starting near the magnet passage or far from the magnet passage. These are all important variables, but in most cases, regardless if you put the coil one way or the other you get the same result. WHY????? It is because the copper atoms don't care about layers. If the impulse on layer 1 can jump direct to layer 2 without going through the actual windings of layer 2, and then jump to layer 3 without going through the windings of layer 3 and so on, because there is more "resistance" in the winding of those layers then for the impulse to simple jump a few layers, this I call Coil Bypass. So I have found that pulse driven coils suffer from Half Coil Syndrome and pick up coils "may" suffer from Coil Bypass. Copper atoms are way smarter then us for now but if we can find their secrets, we will never wind coils the same way again. hehehe
The other thing is this. We need to develop a sure way to scope our devices with only the probe, while leaving the ground open to the atmosphere or connected to a floating coil of an accepted type to make the ground reference the same for all experimenters. If this can be done, then you will be able to see the direct waveform and not this damn differential wave form that says nothing but "Overall, things work like this or that". We cannot advance with overall, we need precise.
Great work as usual and sorry if this post is not the norm.
wattsup
This was posted on my youtube video and though of posting it here as it is the way I see the effect at this time.
Posted by deslomeslager (https://www.youtube.com/user/deslomeslager) 3 hours ago (https://www.youtube.com/watch?v=cr3x0xTqM_k&lc=z13mv35rzuq0cvcdf23hj5rixwafd1bdh)
First of all: nice build as usual! And thank you for sharing. I watched it with pleasure, and hope to see the next one soon. I think of the rod as a piece of elastic band. And the prime mover as an up-down shifting device as an analogy). The coil is the 'closed end' for the standing waves. As you move the coil you are actually shortening the piece of elastic band (or cord, perhaps it should not be elastic at all). I hope the analogy stands for a bit. What it does not explain or what is not in proportion is about the phase shift. There will be a point where the emf will help rotating the prime mover. On the other hand, if the closed end of a cord is changed in an open end, the amplitude can go to twice it's maximum value since there is a returning wave which adds up. Is this a bad comparison?
My reply:
I'm thinking of the core more like water. The magnet flux, like a wave on the water. The wave is first created by the magnets movement which moves through the core like a wave on water. The coil represent an obstacle to the wave. So if it's close to the beginning of the core the coil reflects the wave back to the magnet which happens to be the same pole the wave was created causing a braking effect to the magnets movement (Lenz Law). Now move the coil back far enough on the core and by the time the wave hits the coil and reflected back to the magnet, the magnet may have had enough time to rotate to the next pole (opposite) which will cause an attraction (acceleration) which is the reverse of Lenz.
As for why different coils cause different result is caused by the coils time constant (charge time) which will dictate on how much time it take for the wave to be reflected back the magnet.
Also, another variable is, If the coil is under load at the same time, this will dictate on how much of the waves force will be reflected back to the magnet, hence reducing its capability of assisting.
I would tend to think the most efficient energy transfer (using this effect) would be to adjust it so the time constant and load completely absorbs the wave and nothing is returned which will cause no lost in magnet movement and no gain.
Now, to say there are no losses to the magnets movement would not be completely correct, as we know Eddy currents in water cause losses and are also present in the core material. However, using the newest technology in thin core material will alleviate much of these losses.
Hope this helps.
Luc
When I read Lucs posts last night it all reminded me of Romeros thread.
Glad to see you chime in Romereo. ;)
Its good to see this come back to life. ;D
Going to shop to build some things. ;)
Mags
mh,
could you create such a timing diagram that you mentioned to the best of YOUR knowledge of what is happening in this video? I would love to see your comment in a way that builds constructively.
Fausto.
Quote from: MileHigh on January 16, 2016, 10:04:39 AM
It simply doesn't work like that and there is no "magnification process" taking place. Plus the language being used does not make sense, coils don't "add amperage."
Every one of these setups needs to be evaluated on a case by case basis. There is no generic "advice" on how to see a rotor increase in speed when the configuration is changed.
And "configuration is changed" is the key phrase. I make a change to my system by adding a load. Therefore there are two configurations to analyze, without the load and with the load. All off the voltages and currents need to be measured and a complete power audit has to be done for each configuration, never forgetting to account for the waste heat. Countless times experimenters have been thrown off and they confuse "increased output" for what is really less waste heat.
If you really want to understand a setup then you should construct a timing diagram with as much information as possible incorporated in the timing diagram. All of the answers explaining the how and why and when of the setup are revealed in the timing diagram.
Quote from: romerouk on January 16, 2016, 08:55:12 AM
The best way is to maintain the same speed under load while the power generated is of a considerable amount.
Well said. Getting output current 'without' affecting the speed of the driven rotor. Meaning that you get output without loading the rotor motion, thus not an increase in input to the rotor. :o ;D
Mags
Just a week or so ago I had posted that I went and read some of the beginning of the Muller Dynamo thread where Romero was putting his motor together. And I said it was still inspiring. Well today makes it even more.
Been playin with my motor setup and fiddling with magnet biasing the core to reduce cogging and it works well. Depending in the core used, magnet used and distances adjusted. Was just getting into rearranging those as the pickup coil is loaded. So it doesnt have to be a long core with a sliding coil to find the same effect. Just sayin there is more than one way to skin that cat, as Romero had shown some time ago. ;)
Mags
Quote from: plengo on January 16, 2016, 01:59:41 PM
mh,
could you create such a timing diagram that you mentioned to the best of YOUR knowledge of what is happening in this video? I would love to see your comment in a way that builds constructively.
Fausto.
How can I possibly create a timing diagram when it's not my experiment? The timing diagram would likely help explain the observed phase shift between the pancake coil and the movable coil.
The closer the movable coil is to the rotating magnet the more flux passes through the coil. In other words the coupling coefficient between the rotating magnet and the movable coil improves the closer they are together. Since the movable coil drives a resistive load let's assume that it is purely a resistive load relative to the rotating magnet. There is a phase shift issue which is not fully explained, but at least we can say that the resistance of the coil wire and the load resistor itself look like a purely resistive load at these low frequencies. When the movable coil is far away from the rotating magnet then a lot of stray flux leaks out the the sides of the shaft which should look like a reactive load to the rotating magnet. So as the movable coil moves back and forth there is an interplay between a reactive and resistive load from the perspective of the rotating magnet.
When you see a speed up in the Dremel when you add a load, all that you really have to do is make the measurements and calculate the total resistive power dissipation before and after the load is applied. Almost certainly, you will find that the total resistive power decreases when the load is added. You can't forget that when the total load resistance is very low, like this case where the coil resistance is 6 ohms plus the load resistor is 0.1 ohms, there may be an impedance mismatch. Assuming this is the case, then there is an impedance mismatch with the Dremel on the low side - and therefore the resistive power dissipated in (and transferred to) the load goes down and as a result the Dremel speeds up.
Several people are suggesting "exotic" explanations before the most basic number crunching is done - make measurements and calculate how much total resistive power is being dissipated in the load and relate that back to the observed RPM of the Dremel. You also have very good power consumption data for the Dremel itself which should not be ignored.
In the final analysis "acceleration under load," really "increased final RPM under load," is most likely because when you "add a load" you actually end up decreasing the mechanical load on the Dremel. Therefore the Dremel speeds up. If you can figure this out to your satisfaction you will realize that nothing special is happening and there is no "coil magic" taking place.
Quote from: MileHigh on January 16, 2016, 05:38:56 PM
You can't forget that when the load is only 0.1 ohms, let's assume that the coil resistance of 6 ohms plus the load resistance of 0.1 ohms results in an impedance mismatch with the Dremel on the low side - and therefore the resistive power dissipated in (and transferred to) the load goes down and as a result the Dremel speeds up.
Luc did say his coil resistance was so low it was not measurable with his equipment. Most meters go to .1 ohm. I have a coil that looks similar and is .53ohm reading with a meter that goes to .01ohm. His may have larger wire and fewer turns than mine.
Mags
Quote from: Magluvin on January 16, 2016, 05:54:08 PM
Luc did say his coil resistance was so low it was not measurable with his equipment. Most meters go to .1 ohm. I have a coil that looks similar and is .53ohm reading with a meter that goes to .01ohm. His may have larger wire and fewer turns than mine.
Mags
Yes Mags, the coil I showed in the video (but did not demonstrate) has too low of a resistance to measure.
I'm quite sure mine has finer wire then yours as I used the same gauge (23AWG or 0.6mm) wire, which is same gauge as the coil demonstrated. It's just wound in the most unusual way.
Using a wire resistance chart I was able to calculate the coil to be 0.00135 Ohm.
It has 16uH Inductance (on core)
With an amazingly low magnet rotor frequency of 45Hz and coil position at the furthest position on the rod core, 2.3 in. or 58mm away from magnet rotor, when shorting the coil with its own 10AWG 12 inch long wire leads = 0.002 Ohm load resistor, the magnet rotor goes to 46Hz and 37mV RMS is maintained across the coil = .685 Watt
Open coil voltage at 45Hz is 106mV
Luc
Quote from: gotoluc on January 16, 2016, 06:39:11 PM
Yes Mags, the coil I showed in the video (but did not demonstrate) has too low of a resistance to measure.
I'm quite sure mine has finer wire then yours as I used the same gauge (23AWG or 0.6mm) wire, which is same gauge as the coil demonstrated. It's just wound in the most unusual way.
Using a wire resistance chart I was able to calculate the coil to be 0.00135 Ohm.
It has 16uH Inductance (on core)
With an amazingly low magnet rotor frequency of 45Hz and coil position at the furthest position on the rod core, 2.3 in. or 58mm away from magnet rotor, when shorting the coil with its own 10AWG 12 inch long wire leads = 0.002 Ohm load resistor, the magnet rotor goes to 46Hz and 37mV RMS is maintained across the coil = .685 Watt
Open coil voltage at 45Hz is 106mV
Luc
Well I just wanted to make it clear that your coil was no where near 6ohms along with your resistor. Wasnt a clear comparison.
Funny so far with using the magnet to bias the core that Im working with at the moment, there doesnt seem to be much of a change at all in voltage output of the coil but has less drag on the rotor, when it is set up right. This seems to be a positive thing. Now to check while loaded. And readjust, etc.
Mags
Quote from: verpies on January 16, 2016, 07:32:02 AM
That's a pretty good experiment.
I did it because I know many cannot build things but they like to see these effects.
Quote from: verpies on January 16, 2016, 07:32:02 AM
Note that the conductive rod core constitutes a shorted 1-turn coil that always brakes the rotor.
It is possible for the slidable multiturn coil to interfere with this braking action.
Yes, a real bad core isn't it!... again, it was quick and dirty, just to show the effect.
I may build a better version using Metglas cores... will see if the time permits.
Quote from: verpies on January 16, 2016, 07:32:02 AM
So for a clean experiment you'd need to use a non-conductive core.
Note that "non-conductive" does not mean "without magnetic hysteresis", which is an unrelated property of a material.
Yes, of course ;)
Quote from: verpies on January 16, 2016, 07:32:02 AM
P.S.
Do you have a non-inductive low ohm resistor to use as an input current sensor instead of the clamp-on current sensor ?
Again, quick and simple. When the real time measurements come the input will most likly be DC which is easy to measure. I should of just used DC since that Dremel is a universal motor.
Thanks for your comments.
Luc
Quote from: Dog-One on January 16, 2016, 06:50:35 AM
Very interesting video Luc. Thank you kindly for sharing it with us.
So what we think is happening is the magnetic field is propagating through the core material similar to dominoes falling and like any wave, there are nodes and valleys. When the coil is positioned in the proper location it creates a reflection back to the prime mover that is exactly in tune with its rotation.
This makes me think the coil and core is behaving somewhat like a transmission line and with a transmission line we also have impedance that must be matched. Gets a little confusing because we have magnetic properties as well as electrical properties both in play here.
Your demonstration certainly provides a lot of food for thought. Thanks again.
Thanks, you seem to understand it very well!
Luc
Quote from: wattsup on January 16, 2016, 12:05:26 PM
@gotoluc
Son of a gun. I just saw this thread and your video. hahahahaha Life is just so great sometimes when things just start falling into place.
Here is what I think needs to done next.
To simplify things, since the coil is showing an AC sine wave maybe consider just using a small rheostat and a bulb instead of your resistors. That will give you infinite load adjustment.
What you really want to know here is what is going on in that sliding coil. Taking a differential reading is like calling New York, then calling Los Angeles and then saying "I know what's happening in the USA". Very deceiving.
What we need to see is what is happening on each added layer of that coil. We think that the core to coil impress is making "electrons flow" (using regular terms here for now) through all of that coil which is a multi layer, mag wire type with tight turns and "no space between layers". I have just posted on this and such a situation I see know as producing what I call Coil Bypass. I think that is what you are seeing there.
If you can drill small holes on one side of that plastic coil spool up to the end turns of the coil and just send one pointy probe and scope it and see the difference from one layer or a few layers to the next few layers, this will give you so much more information then you ever had. hahaha
The other experiment is you take two lengths of identical wire and identical spools. You wind one length on one spool as usual, layer after layer, tight. The other you wind same way but you add a spacer between layers so the layers cannot touch each other. Then you do comparison studies of these two and this will again tell you a lot more then you knew before. Remember old transformers with paper between layers. WHY do we not see that anymore? Was is to efficient? hahaha
The point is this. There is technical process and there is reality process. We technically think the impress is "flowing" through that whole coil. But the coil really has three parts. First layer, mid layers and outer layer. The the coil has first layer starting near the magnet passage or far from the magnet passage. These are all important variables, but in most cases, regardless if you put the coil one way or the other you get the same result. WHY? ??? ? It is because the copper atoms don't care about layers. If the impulse on layer 1 can jump direct to layer 2 without going through the actual windings of layer 2, and then jump to layer 3 without going through the windings of layer 3 and so on, because there is more "resistance" in the winding of those layers then for the impulse to simple jump a few layers, this I call Coil Bypass. So I have found that pulse driven coils suffer from Half Coil Syndrome and pick up coils "may" suffer from Coil Bypass. Copper atoms are way smarter then us for now but if we can find their secrets, we will never wind coils the same way again. hehehe
The other thing is this. We need to develop a sure way to scope our devices with only the probe, while leaving the ground open to the atmosphere or connected to a floating coil of an accepted type to make the ground reference the same for all experimenters. If this can be done, then you will be able to see the direct waveform and not this damn differential wave form that says nothing but "Overall, things work like this or that". We cannot advance with overall, we need precise.
Great work as usual and sorry if this post is not the norm.
wattsup
Okay wattsup,
thanks for your post.
I don't know how much I'm going to work on this. It was a quick slap together so some who can't build can see this effect.
Also, to test a special super low impedance coil I've been thinking of building for this effect ,which I built and tested and posted the results.
I may or may not build something better. My priority is still the Motor with flyback assist motor. I'm just waiting for the last parts to come in.
All the best in your research
Luc
Quote from: MileHigh on January 16, 2016, 05:38:56 PM
...There is a phase shift issue which is not fully explained,...
Thanks MH.
Can you expand on this comment? You mean not fully explained scientifically or on the experiment itself?
Fausto.
@All,
what measurements and experiments would you guys propose to measure this at a provable point? Whatever is the point. Sometimes I see people arguing about the "no free energy" on the apparatus and other times it is just implied. In this experiment I did not see or hear the words "free energy" but only "more efficient motor".
MH presented a possible explanation but it is too vague to conclude anything. Gotluc did an amazing job in nailing this effect down into a very simple experiment that we all can replicate (I am about to do it too).
I think we NEED a set of tests and measurements that can scientifically be explained into a MODEL, whatever that model is, so it becomes very clear the whats and hows.
Ideas?
Fausto.
Quote from: plengo on January 17, 2016, 04:03:17 PM
Thanks MH.
Can you expand on this comment? You mean not fully explained scientifically or on the experiment itself?
Fausto.
I mean that it is not explained in the experiment itself. Luc stated that it was just a quick demo of the "effect" and he would not be doing any more for this testing.
About one or two years ago ConradElectro wanted to see "acceleration under load" and quickly reproduced the effect. But we went one step further, we actually measured the power being dissipated on the load side - the pick-up coil and the load resistor. We measured the initial power dissipation and then the power dissipation after the "acceleration." The second measurement showed
less power was being dissipated and therefore that's why the rotor sped up.
You can expect the same thing would happen in this clip with the Dremel. The only rational reason for the Dremel to speed up is if there is
less of a mechanical load on the motor. You can determine the mechanical load by measuring the total electrical load. So it's not "acceleration under load" it's actually "acceleration under less of a load." I am sure that you can find dozens of clips of "acceleration under load" and I bet you that you will not find anyone actually measuring the power dissipated in the total load before and after. The entire concept is not true. In effect, what's happening is an inversion of what the expectation is: People think that they are adding a load, but in fact what they are really doing is reducing the load. So the whole thing is a mistake that took on a life of it's own.
Okay, we can stop this now, it's gone far enough.
MH is mostly right. I must admit the reality of AUL effect is not as good as it looked in my video demo, which I purposely did to demonstrate what many are seeing in their tests and as a learning tool for those who play around with this stuff.
I know better not to use a solid steel rod, a bolt, welding rods, or even for that matter transformer laminations. Unless you want to show or demonstrate this effect just to waste power ???
Core Hysteresis is exactly what causes AUL :o and it comes at a cost to the prime mover.
When you use quality cores like Metglas, 90% or more of AUL goes away. So MH is right about that.
However, the phase shift you saw in the video by sliding the coil further away on the core still remains and I would suggest this is what needs to be further tested (obviously with the right cores) to see if this has any advantages.
I will post a new video demonstrating the reality of AUL when using Metglas core compared to a solid steel core.
Some of you will be surprised of how drastic the change is.
I'm sorry if this has caused some people grief or trouble. My intention is to bring awareness on the subject which has been highly debated over the years.
Stay tuned for the comparison test
Luc
Quote from: gotoluc on January 17, 2016, 07:47:39 PM
However, the phase shift you saw in the video by sliding the coil further away on the core still remains and I would suggest this is what needs to be further tested (obviously with the right cores) to see if this has any advantages.
Thanks for the note gotluc. I see MH point and your emphasis on the phase shift which is very significant since this is the area between apparent power and real power manifestation (usage). Removing load (MH argument) is logical but does not explain indeed the phase shift which seams to be the main variable here.
Fausto.
Luc:
If you claim core hysteresis is the main cause of "AUL" and if you one day choose to pursue this further then you have back up that claim with solid data. Right now I am not smelling that at all, and it would probably not be trivial to measure core hysteresis losses and it would only be one part of the load on the prime mover.
My feeling is that the electrical load due to the coil + resistor in any before/after configuration analysis is the main agent that is causing a mechanical load on the prime mover, and hysteresis losses would be secondary. It's just a feeling with no measurements to back it up.
It's hard to say where the phase shift is coming from exactly because I don't know exactly how to model the setup. The model might be as simple as a coil (stray inductance) and a resistor (pickup coil driving resistive load) in series. Without being sure, it would at least appear there is a decent chance that the stray inductance leaking out of the core when the movable coil is far away is the main cause of the phase shift. I seriously doubt the phase shift is having a large impact on the final RPM but one more time you never know. Like I said before, the best way to approach that would be to do a timing diagram analysis where you plot the estimated back-torque on the prime mover during a full revolution.
The real moral of the story for the people that this was being presented to is to make proper measurements and do your best to properly interpret your measurements and analyze them. Full schematics, measurements, interpretation and analysis, and then trying to draw the proper conclusions. That's the way for experimenters to properly share data and work together in a synergistic manner. However, a good first start would be to simply measure the electrical power dissipated on the coil + load resistor for the "before" and "after" configurations. If the power dissipation data is leaping out at you as an explanation for the "effect" then that should be sufficient. People can still work on measuring the core losses if they want to see where that leads them.
It may all sound like a big pain in the ass but this is real electronics. Taking shortcuts is too dangerous and can lead to improper conclusions.
MileHigh
@gotoluc
OK but listen,
you already did the experiment right and at around 13 min you showed the cogging. So the cogging proves you found a good slide position on the core no matter the material, cogging is a good sign. So what is the cogging saying to you? Maybe it's saying "Hey man, I want to give you some good amps and all you want with that fat single coil is volts."
Now how could you increase amps instead of volts? Maximum output has always been a dance between volts and amps. Is it possible that you can output more watts when working to output more amps? Or a mix of both that come together parallel. These are not bad questions to answer again regardless of the core if you are getting cogging on the drive motor that becomes a base.
wattsup
Okay everyone, I made the video as promised but like TinMan says, better make some popcorn cause it's a long one. Actually the longest video I have ever made!... 45 minutes of boring measurements ;D
Hope this helps bring a better understanding on this effect.
Link to the movie: https://www.youtube.com/watch?v=NYGM4UlnqTM (https://www.youtube.com/watch?v=NYGM4UlnqTM)
Enjoy
Luc
@gotoluc
As usual good work in trying to define that effect. I made a post but forgot to post it before I left for the office, so I will make this quick.
The metglass lams are placed horizontal in your set-up and the rotating magnet is also horizontal but smack dab aligned to the center of the metglass. What I think is happening is the center 3rd of the metglass icore which is closest to the magnet passage is getting all the impress leaving very little to the top and bottom 3rds which are the ones the coil will see and react to as change. Maybe realign the magnet so its closest point is aligned with the top or bottom 3rd and try your test again. See if the metglass now does the same as the rod.
Thanks for your works man.
Added: I forgot to also mention this.
You did not talk about that vertical pancake coil next to the magnet. It is also probably affecting the metglass as an impress brake more then it does on the regular rod, so maybe try connecting and disconnecting that coil as well.
wattsup
Quote from: wattsup on January 19, 2016, 10:14:18 AM
@gotoluc
As usual good work in trying to define that effect. I made a post but forgot to post it before I left for the office, so I will make this quick.
The metglass lams are placed horizontal in your set-up and the rotating magnet is also horizontal but smack dab aligned to the center of the metglass. What I think is happening is the center 3rd of the metglass icore which is closest to the magnet passage is getting all the impress leaving very little to the top and bottom 3rds which are the ones the coil will see and react to as change. Maybe realign the magnet so its closest point is aligned with the top or bottom 3rd and try your test again. See if the metglass now does the same as the rod.
Thanks for your works man.
Added: I forgot to also mention this.
You did not talk about that vertical pancake coil next to the magnet. It is also probably affecting the metglass as an impress brake more then it does on the regular rod, so maybe try connecting and disconnecting that coil as well.
wattsup
Hi wattsup,
it makes no difference to the effect if I raise or lower the rod in relation to the center of the magnet rotor.
Luc
Well, I am baffled because the clip shows that the "effect" is exactly what I said it was. It has nothing to do with the choice of core material and everything to do with the magnitude of the mechanical load on the prime mover. In this experiment all that you have to do is measure the electrical load due to the coils and load resistors and that becomes the mechanical load on the prime mover. Eddy current losses and hysteresis losses also simply become more of a mechanical load on the prime mover and also act to slow it down.
Starting at about 20:00 minutes into the clip you have the most dramatic "acceleration under load" when the 10-ohm resistor gets changed to the 1-ohm resistor. Luc even acknowledges that the electrical load decreases when he does this.
With the 10-ohm resistor, the total electrical load is about 1.58 watts.
Then the load resistor is changed to 1-ohm, the prime mover speeds up, and the total electrical load is about 0.98 watts.
So, "acceleration under load" is really "acceleration (to a higher final RPM) under reduced load." In that sense there is no "effect."
Quote from: gotoluc on January 18, 2016, 10:55:34 PM
Okay everyone, I made the video as promised...
Link to the movie: https://www.youtube.com/watch?v=NYGM4UlnqTM (https://www.youtube.com/watch?v=NYGM4UlnqTM)
Good video! I agree with your experimental methodology and manner of analysis and reasoning.
I see a mathematical mistake in it though.
There are several 2-variable formulas for calculating average power, such as:
P=V*i
P=V
2/R
P=R*i
2...and there seems to be confusion when to use an RMS value and when to use the arithmetical MEAN value, in these formulas.
The distinction is very simple:
- If you see a
squared current or voltage in the formula, then you should use the RMS value for it.
- If you see a non-squared current or voltage in the formula, then you should use the MEAN value for it.
IMPORTANT: In the formulas above,
only one variable can vary in time and the second variable must be constant (it cannot vary in time).
If both variables vary in time, then you must use an oscilloscope and its MATH function to calculate power one instance at a time, by multiplying 2 channels and averaging the results, unless the current and voltage have exactly the same shape and you know their exact phase offset.
According to the rules above, it was perfectly fine to use the RMS voltage in the formula P=V
2/R to calculate the average power dissipated in a 10Ω resistor, because its resistance was constant (10Ω) while the voltage across it was variable and
squared in the formula.
But it was not OK to use the RMS current to calculate the power supplied to the "JobMate" motor according to the formula P=V*i although the supply voltage was constant at 28VDC, because the current in this formula was not squared .
P.S.
Some multimeters are capable of calculating the RMS values of non-sinusoidal waveforms ...up to a certain frequency.
e.g. my Fluke 87 can do it and I just recently verified it on a 330Hz sawtooth waveform.
Quote from: wattsup on January 19, 2016, 10:14:18 AM
You did not talk about that vertical pancake coil next to the magnet. It is also probably affecting the metglass as an impress brake more then it does on the regular rod, so maybe try connecting and disconnecting that coil as well.
That coil does not exert any influence on the rotor because no significant current is allowed to flow through it.
A coil without current might not as well exist at all.
Hi verpies,
you may not of noticed but the meters measuring the supplied voltage and current for the prime mover (jobmate) are set up as a Low Pass Filter.
I call it my cap bank meters which are permanently setup as a low pass filter (see pics) where the current (right DMM) is measuring the DC voltage across a 0.1 Ohm resistor which is connected between the right 3,900uf capacitor to the left 3,900uf capacitor. The left DMM is measuring the voltage across the left capacitor which includes the voltage drop.
Knowing this I now believe you would agree the test data to be correct?
Thanks for your help
Luc
Quote from: gotoluc on January 22, 2016, 11:56:45 AM
you may not of noticed but the meters measuring the supplied voltage and current for the prime mover (jobmate) are set up as a Low Pass Filter.
Indeed, I have not noticed.
A low Pass Filter with low enough cutoff frequency is effectively an averaging circuit.
But I would add small ceramic or film capacitors in parallel with the big electrolytic caps because big caps can have a high ESR at higher frequencies that lets those through.
Quote from: gotoluc on January 22, 2016, 11:56:45 AM
The left DMM is measuring the voltage across the left capacitor which includes the voltage drop.
So the energy flows form the right cap to the left cap?
Quote from: gotoluc on January 22, 2016, 11:56:45 AM
Knowing this I now believe you would agree the test data to be correct?
Yes, the input power of the prime mover was correctly calculated.
Quote from: verpies on January 22, 2016, 12:15:21 PM
So the energy flows form the right cap to the left cap?
No, the Left cap is the DC input filling Right cap (through resistor) and why I mentioned the left DMM is measuring the voltage across the right cap since there will be a voltage drop caused by the resistor.
I also had a 100000uf cap between the prime mover and the low pass filter output cap to make sure there was a smooth transition between the two.
I agree on adding a 0.1uf across the low pass filter output cap. But for the low frequency the prime mover was I'm sure it was adequate.
I'll add it in case I use it for high frequency work.
When ever DC is being switched on and off, I always use this low pass filter metering system.
I suggest everyone to build one for this purpose which makes measurements simple and accurate.
Thanks for your help
Luc
Quote from: gotoluc on January 22, 2016, 12:38:30 PM
No, the Left cap is the DC input filling Right cap (through resistor) and why I mentioned the left DMM is measuring the voltage across the right cap since there will be a voltage drop caused by the resistor.
That's wrong. For input power measurements purposes, the voltage should be measured AFTER the voltage drop caused by the CSR.
Otherwise you are also measuring the power dissipation of the CSR.
Quote from: verpies on January 22, 2016, 01:54:08 PM
That's wrong. For input power measurements purposes, the voltage should be measured AFTER the voltage drop caused by the CSR.
Otherwise you are also measuring the power dissipation of the CSR.
I don't know where the confusion is but I tried my best to describe the voltage is measured after the CSR voltage drop!
re-read the below
Quote from: gotoluc on January 22, 2016, 12:38:30 PM
No, the Left cap is the DC input filling Right cap (through resistor) and why I mentioned the left DMM is measuring the voltage across the right cap since there will be a voltage drop caused by the resistor.
Luc
@gotoluc
Below is an image I grabbed from your first video showing the position of the magnet versus the iron core.
What I am just curious to know is what was the process you used to finally decide to position your spinning magnet at that particular location? I think everything starts with that one consideration since nothing in the other variables could compensate for any loss of impress caused by a potential faulty fixed magnet/core position, maybe faulty is not the right word, maybe saying less favorable would be more appropriate.
Another way of asking this is..... how sure are you that the magnet-to-core position is the optimal position for this type of experiment where the initial premise is that the core is receiving the maximum degree of magnetic change in order to impart that change to the coil? If that one consideration is optimized, would that optimal performance leave any room for any acceleration under load or is the acceleration due to the fact that the magnet to core relation was not optimized and hence any other change on the core now has room to influence the drag level on the prime mover. Again hard to explain. hahaha
Instead of making a video I am just posting another image showing a simple pair of magnets in attraction mode so their N/S poles are facing out secured on a simple drill shaft and a compass. With these two simple toys you can very quickly do micro tests for core to magnet positioning. The magnet is very easy to turn with your fingers and see some pretty crazy differences in effects when held horizontal or vertical to the compass or when the compass itself is held horizontal or vertical to the magnet. You soon realize that one or the other relative to the Earth plane also makes for some very curious and contradictory effects.
I also use this on my drill to test other effects in angular spin. I use another pair as this but having both poles out as north and another with both out as south. Very easy tools for magnetic effects.
The final diagram I have made is to show something else. I have a very bad feeling that when a round magnet passes in front of a round core and coil, the actual passage generates more cancelled impress then the impress that can actually produce output, output which is only occurring because through this very complex magnet to core to coil interchange that is happening on on such circular geometries.
The diagram shows several coil geometries relative to the same magnet passage. The second group shows ways of keeping the magnet only on one half of the core/coil so that the massage can generate a more "directional" impress that would favor more "directional" output, versus the standard method we use where the magnet arrives at the coil/core from the left side first, (ok - good), then splits to the top and bottom of the coil (bad - causing extreme cancellation) then leaving them on the other side (good - but not great).
The coil/core #7-8 and #9-10 are the ones I believe will be the most productive because each only receives one constant and directional impress so the cancellation should be held to a minimum.
This is just theory right now but I wanted to put this out there in case others are consider any line of experimentation where such considerations could be easily added as tests in the same process.
wattsup
PS: Hope this is not tooooooo of topic.
Quote from: gotoluc on January 22, 2016, 02:02:57 PM
I don't know where the confusion is
Probably from the lack of a diagram. As you probably heard - a picture is worth a 1000 words.
Did you have Diag.5B in mind ?:
Quote from: verpies on January 23, 2016, 11:39:05 AM
Did you have Diag.5B in mind ?:
Close but the below is the exact setup of metering of the DUT
Now it should be clear for anyone to build one of these for their own accurate input power tests.
Luc
Quote from: wattsup on January 23, 2016, 10:58:53 AM
@gotoluc
Below is an image I grabbed from your first video showing the position of the magnet versus the iron core.
What I am just curious to know is what was the process you used to finally decide to position your spinning magnet at that particular location? I think everything starts with that one consideration since nothing in the other variables could compensate for any loss of impress caused by a potential faulty fixed magnet/core position, maybe faulty is not the right word, maybe saying less favorable would be more appropriate.
Another way of asking this is..... how sure are you that the magnet-to-core position is the optimal position for this type of experiment where the initial premise is that the core is receiving the maximum degree of magnetic change in order to impart that change to the coil? If that one consideration is optimized, would that optimal performance leave any room for any acceleration under load or is the acceleration due to the fact that the magnet to core relation was not optimized and hence any other change on the core now has room to influence the drag level on the prime mover. Again hard to explain. hahaha
Instead of making a video I am just posting another image showing a simple pair of magnets in attraction mode so their N/S poles are facing out secured on a simple drill shaft and a compass. With these two simple toys you can very quickly do micro tests for core to magnet positioning. The magnet is very easy to turn with your fingers and see some pretty crazy differences in effects when held horizontal or vertical to the compass or when the compass itself is held horizontal or vertical to the magnet. You soon realize that one or the other relative to the Earth plane also makes for some very curious and contradictory effects.
I also use this on my drill to test other effects in angular spin. I use another pair as this but having both poles out as north and another with both out as south. Very easy tools for magnetic effects.
The final diagram I have made is to show something else. I have a very bad feeling that when a round magnet passes in front of a round core and coil, the actual passage generates more cancelled impress then the impress that can actually produce output, output which is only occurring because through this very complex magnet to core to coil interchange that is happening on on such circular geometries.
The diagram shows several coil geometries relative to the same magnet passage. The second group shows ways of keeping the magnet only on one half of the core/coil so that the massage can generate a more "directional" impress that would favor more "directional" output, versus the standard method we use where the magnet arrives at the coil/core from the left side first, (ok - good), then splits to the top and bottom of the coil (bad - causing extreme cancellation) then leaving them on the other side (good - but not great).
The coil/core #7-8 and #9-10 are the ones I believe will be the most productive because each only receives one constant and directional impress so the cancellation should be held to a minimum.
This is just theory right now but I wanted to put this out there in case others are consider any line of experimentation where such considerations could be easily added as tests in the same process.
wattsup
PS: Hope this is not tooooooo of topic.
Hi wattsup,
It's just tooooooo much to read. Please ask one question at a time. I've lost interest in this effect some years back and even more now that I've been able to test it with a quality core like Metglas.
I'll answer your first question:
The reason the core is placed on the end of the magnet is for mechanical reasons. For example is it was on the opposite end it would cause much more pull on the shaft of the Dremel tool which causes flex and at a certain rpm can cause vibration aka harmonics.
Luc
Quote from: gotoluc on January 23, 2016, 01:00:18 PM
Close but the below is the exact setup of metering of the DUT
All is clear now.
This system is accurate if the caps are huge (yours are) and have low impedance at all the frequencies generated by the DUT.
The brush noise of a universal motor can contain frequency components well in the MHz region.
Hello guys, I'd like to let you know I'm uploading a lot of your interesting videos in a youtube channel here:
https://youtube.com/channel/UCueT6f8K_BYW_BJ4vVqdO6Q
and also a Facebook page here: https://facebook.com/AccelerationUnderLoad/
If you have any other interesting videos of accelerating devices, please let me know! I'm building a machine that will be released in Open Source soon.
Stefan Danov