Hi everyone,
It's been a while since I posted a new video!
Lately I've been thinking of applying what I personally learned while working with Thane Heins at the Ottawa University a few years back. I'm now considering of re-testing Thane's high Inductance coils with new core material and biasing magnets.
A little over a year ago a researcher named Eric YouTube user ericsclips: http://www.youtube.com/watch?v=PuzSkKlnCzc
He also shared his findings at this Forum: http://www.physicsforums.com/showthread.php?t=399801
What he found was that a coil wound on a Finemet toroid (nanocrystaline) core would increase in Inductance as much as 3 time when approached to a magnet (up to a certain point)
I do have 2 of theses Finemet toroids so I wound a coil on one to test it.
The idea here is to use Finemet as core material on Thane's delayed Lenz coil technique. This may give a huge advantage as we could achieve higher than expected Inductance using minimal wire lengths.
High Inductance is the key factor to Thane's coil effect and the benefit of using less wire is not just less cost but it reduces the coils resistance which in turn gives more current output.
Here is the video of my test so far: http://www.youtube.com/watch?v=_cCYKChCFqk
I also included (below) the two scope shots from the video demo test.
Please post your comments.
Thanks for looking
Luc
Quote from: gotoluc on September 07, 2011, 11:14:19 PM
Hi everyone,
It's been a while since I posted a new video!
Lately I've been thinking of applying what I personally learned while working with Thane Heins at the Ottawa University a few years back. I'm now considering of re-testing Thane's high Inductance coils with new core material and biasing magnets.
A little over a year ago a researcher named Eric YouTube user ericsclips: http://www.youtube.com/watch?v=PuzSkKlnCzc
He also shared his findings at this Forum: http://www.physicsforums.com/showthread.php?t=399801
What he found was that a coil wound on a Finemet toroid (nanocrystaline) core would increase in Inductance as much as 3 time when approached to a magnet (up to a certain point)
I do have 2 of theses Finemet toroids so I wound a coil on one to test it.
The idea here is to use Finemet as core material on Thane's delayed Lenz coil technique. This may give a huge advantage as we could achieve higher than expected Inductance using minimal wire lengths.
High Inductance is the key factor to Thane's coil effect and the benefit of using less wire is not just less cost but it reduces the coils resistance which in turn gives more current output.
Here is the video of my test so far: http://www.youtube.com/watch?v=_cCYKChCFqk
I also included (below) the two scope shots from the video demo test.
Please post your comments.
Thanks for looking
Luc
is the square part of the pulse the load time?
thanks for sharing.
Quote from: toranarod on September 08, 2011, 02:00:12 AM
is the square part of the pulse the load time?
thanks for sharing.
Yes, it is the on time. Both have the same on time.
Thanks for looking
Luc
Hi Luc
With regards to the increase of core inductance,This is quite normal.as these
cores are "Square Loop" .Bringing the core close to a bias magnet will push it into
a high permeability zone of the core.For your interest this effect will also occur in other non tape wound cores ,but are Square Loop..i know this having worked with square loop cores in the construction computer memory stores in the 1950`s.
You will find the toroid's make really good pulse motor drivers.
also check this out.
http://www.metglas.com/downloads/finemet_magamp.pdf
Just another point 3R1 cores are a lot cheaper than the tape wound.Here is some info.http://www.ferroxcube.com/appl/info/square.pdf
Also if you are in the UK you can get them from |Farnell
Best Regards Dave
Hi Luc,
lecture on kinetic inductance Lk. Pay notice to his remark about thin-films. This finemet inductors are made from thin-film-layers.
http://www.youtube.com/watch?v=MAHkYROmriY&feature=related
Besides this- there is no increase in the inductance as the negative spike amplitude is decreased. Also the area the first curve containes is also decrease meaning : the magnetic energy is reduced. The meter is fooled as the oscillation is damped as it is clearly seen in you vid. The higher fourier-components 2nd, 3 rd and 5 th are strongly damped. Look at the decreasing slope and the damping of the negative overshoot at the cut-off.
These finmet-core are especially designed for damping high frequencies running along conductors and doing their job well.
This physicist should know this.
These cores are interesting in that you can use them for delaying the collapse-time of the magnetic field whe used in series with the coils in a mull-generator - thus one will be able to control the point in time the anti-lenz appears.
Regards
Kator01
Hello ,
please note the difference between square lopp cores and metglas:
the finemet core, see description : supressing surge in current and voltage
http://www.metglas.com/products/page5_2_2_3_3.htm
square lopp cores are designed for magnetic amplifier applications.
Do not get confused. Modern Electronic components are specifically designed for distinctive applications.
Damping and controlling by saturation is something of a big difference.
So using it for new exotic applications such as the muller-gen you have to know which is doing what.
Kator01
Quote from: firlight on September 08, 2011, 06:51:30 AM
Hi Luc
With regards to the increase of core inductance,This is quite normal.as these
cores are "Square Loop" .Bringing the core close to a bias magnet will push it into
a high permeability zone of the core.For your interest this effect will also occur in other non tape wound cores ,but are Square Loop..i know this having worked with square loop cores in the construction computer memory stores in the 1950`s.
You will find the toroid's make really good pulse motor drivers.
also check this out.
http://www.metglas.com/downloads/finemet_magamp.pdf
Just another point 3R1 cores are a lot cheaper than the tape wound.Here is some info.http://www.ferroxcube.com/appl/info/square.pdf
Also if you are in the UK you can get them from |Farnell
Best Regards Dave
Hi Dave,
thanks for looking at this topic and posting your comment.
I have this model of FERROXCUBE: http://uk.farnell.com/jsp/search/productdetail.jsp?SKU=3057010
However, I tried it before starting this topic and a magnet does not boost its Inductance. So I cannot accept your conclusion at this point that this happens in Square Loop cores. Something is different with the Finemet core.
Please try it yourself and report your findings
Thanks for sharing
Luc
Quote from: Kator01 on September 08, 2011, 09:53:38 AM
Hi Luc,
lecture on kinetic inductance Lk. Pay notice to his remark about thin-films. This finemet inductors are made from thin-film-layers.
http://www.youtube.com/watch?v=MAHkYROmriY&feature=related
Besides this- there is no increase in the inductance as the negative spike amplitude is decreased. Also the area the first curve containes is also decrease meaning : the magnetic energy is reduced. The meter is fooled as the oscillation is damped as it is clearly seen in you vid. The higher fourier-components 2nd, 3 rd and 5 th are strongly damped. Look at the decreasing slope and the damping of the negative overshoot at the cut-off.
These finmet-core are especially designed for damping high frequencies running along conductors and doing their job well.
This physicist should know this.
These cores are interesting in that you can use them for delaying the collapse-time of the magnetic field whe used in series with the coils in a mull-generator - thus one will be able to control the point in time the anti-lenz appears.
Regards
Kator01
Thanks Kator01 for looking at this topic and posting your comments.
I will look into this some more.
One thing is for sure that when a PM is close these cores delay the flyback. Just this effect could be worth something.
Do you know or can explain why it uses much less current when a PM field is applied?
Thanks for sharing
Luc
Quote from: gotoluc on September 08, 2011, 10:47:32 AM
Hi Dave,
thanks for looking at this topic and posting your comment.
I have this model of FERROXCUBE: http://uk.farnell.com/jsp/search/productdetail.jsp?SKU=3057010
However, I tried it before starting this topic and a magnet does not boost its Inductance. So I cannot accept your conclusion at this point that this happens in Square Loop cores. Something is different with the Finemet core.
Please try it yourself and report your findings
Thanks for sharing
Luc
Hi Luc
I measured the increase in inductance in Square loop cores about four
years ago when playing around with Steorns Orbo.Any way I did a quick test again
It was what I expected with the same core I used then.
26.5mH no magnetic bias 33.8mH with Magnetic Bias.With Square loop the increase
of inductance will remain until it is reset by a reverse bias.As you can see the increase is not as great as your tape wound core,but that is to be expected being made from a more exotic material.The answer to your question why is there a reduction in current when your core is biased,is because the inductance has increased therefore so has the impedance .When you bias your core as shown in your Vid, does the inductance remain high when you remove the bias magnet?
Regard Dave
Quote from: Kator01 on September 08, 2011, 10:21:00 AM
Hello ,
please note the difference between square lopp cores and metglas:
the finemet core, see description : supressing surge in current and voltage
http://www.metglas.com/products/page5_2_2_3_3.htm
square lopp cores are designed for magnetic amplifier applications.
Do not get confused. Modern Electronic components are specifically designed for distinctive applications.
Damping and controlling by saturation is something of a big difference.
So using it for new exotic applications such as the muller-gen you have to know which is doing what.
Kator01
Hi Kator
Just looked at the link to Metglas ,I don`t quite get what you mean,about the difference,in the type of core.Metglas is the name of the Company.
It looks like to me Square Loop and surge suppression use the same core ,click on the the data link on that page.
Regards Dave
Naudin test
http://jnaudin.free.fr/2SGen/indexen.htm#hysteresis
http://jnaudin.free.fr/2SGen/indexen.htm
http://jnaudin.free.fr/2SGen/images/inductive_conversion.pdf
Hi Dave,
you are absolutely right, I just checked the BH-Curve of these finemet-core.
Now I might add some information concerning the current -reduction.
I have studied the old transductor-techniques ( 1930) now for about one year including extensive practical testing for power-level up to 1,5 KW. I mention this so that your know that I am speaking from practical experience about the following process:
If you look at the attached pic which I extracted from the Fe SquareLoop-Core-brochure, I have added 2 red arrows which mark the level of a static pre-magnetisation - done either by approaching a magnet ( like Luc did) or by a dc-current through an additional control-winding. Now the remaining magnetic loop oscillates between almost full inductance starting at the level marked by the arrows and low inductance in the right upper saturation-area. In such a way you have no reverse-magnetisation which takes place if you make the way around the full loop ( see the bottom--figure). Therefore you have no de-and remagnetisation-losses. You just use a smaller BH-Area of the curve. You just use a well known magnetic-amplifier-technique. I had the chance to visit a company here in germany which produces transductors ( part of a magamp ) and I was told the the losses using a normal transformer-lamination for 50 Hz for these devices is no more than 5 % of the maximum-power to be controlled. A 20 KW-transductor in the size of a small briefcase consumes 1000 W for controlling the power-out.
Using permagnet magnets just needs the kinetic energy for approaching the coil.
Regards
Kator01
Hello all,
just a remark on naudins experiment : he did not magnetize the core symmetrically like Luc did. So the curves can not be compared. Secondly there is a difference pulsing the coil without a counter-permanent-magnet like in the muller-setup. Here one static and one dynamic magnetic field work against each other including dc-puls in the coil.
Third the coils in the muller-gen are solenoid-coils with both ends facing high magnetic resistance ( air) alternating to a state of very strong magnetic fieldstrengh in the airgap if the magnet fly by.
So this process is much more complicated in the muller-gen.
Kator01
Quote from: firlight on September 08, 2011, 03:16:38 PM
Hi Luc
I measured the increase in inductance in Square loop cores about four
years ago when playing around with Steorns Orbo.Any way I did a quick test again
It was what I expected with the same core I used then.
26.5mH no magnetic bias 33.8mH with Magnetic Bias.With Square loop the increase
of inductance will remain until it is reset by a reverse bias.As you can see the increase is not as great as your tape wound core,but that is to be expected being made from a more exotic material.The answer to your question why is there a reduction in current when your core is biased,is because the inductance has increased therefore so has the impedance .When you bias your core as shown in your Vid, does the inductance remain high when you remove the bias magnet?
Regard Dave
Hi Dave, thanks for posting your additional comments and new test results.
I'll try again to see if I can get a small Inductance change in the FERROXCUBE.
Concerning the current drop when the core is biased. You believe there is an inductance gain! ... how interesting. Kator01 says there is no Inductance gain. I don't know what an Inductance gain would look like on the scope. So I started this topic to see if anyone has the answers. So far we have a split.
Not sure why you ask "does the inductance remain high when you remove the bias magnet?"
I think the answer is no but I show the differences in the video (with and without magnet)
Thanks for sharing
Luc
Quote from: Kator01 on September 08, 2011, 08:03:21 PM
Hi Dave,
you are absolutely right, I just checked the BH-Curve of these finemet-core.
Now I might add some information concerning the current -reduction.
I have studied the old transductor-techniques ( 1930) now for about one year including extensive practical testing for power-level up to 1,5 KW. I mention this so that your know that I am speaking from practical experience about the following process:
If you look at the attached pic which I extracted from the Fe SquareLoop-Core-brochure, I have added 2 red arrows which mark the level of a static pre-magnetisation - done either by approaching a magnet ( like Luc did) or by a dc-current through an additional control-winding. Now the remaining magnetic loop oscillates between almost full inductance starting at the level marked by the arrows and low inductance in the right upper saturation-area. In such a way you have no reverse-magnetisation which takes place if you make the way around the full loop ( see the bottom--figure). Therefore you have no de-and remagnetisation-losses. You just use a smaller BH-Area of the curve. You just use a well known magnetic-amplifier-technique. I had the chance to visit a company here in germany which produces transductors ( part of a magamp ) and I was told the the losses using a normal transformer-lamination for 50 Hz for these devices is no more than 5 % of the maximum-power to be controlled. A 20 KW-transductor in the size of a small briefcase consumes 1000 W for controlling the power-out.
Using permagnet magnets just needs the kinetic energy for approaching the coil.
Regards
Kator01
Hi Kator01,
thanks for posting this additional information.
Regarding your explanation on the current drop when the core is biased with the magnet. Unfortunately I don't have any schooling!... so I can't grasp anything that would require this knowledge. What I'm trying to tell you is, after reading your post I don't understand it any better as to why the current drops then before. If you can explain it in a layman way maybe I'll get it.
What I have learned to date is all through physical experiments, trial and error.
ADDED
One thing I would like to add is, if we compare both scope shots, one is no magnet and the other is with magnet. You say there is no increase in Inductance when the magnet is added since the flyback spike at off time is flattened. However, I would like to bring to your attention that with no magnet the current is 230uA and with the magnet it drops to 80uA which is about 75% less current used. So one could expect a change in flyback output. Another thing to consider on the core with magnet is, even though the flyback does not have a long high voltage spike after the off time but notice how much wider it is. See the off time waves I posted below. The core with magnet may have just as good of an RMS value on the off time flyback then the narrow high voltage spike. If we compare each wave after the off time by surface area (RMS) I find they look to take about the same surface. So if one is taking 75% less current and the fyback is about the same RMS value then is this not something to consider?
Thanks for sharing
Luc
Hi Luc,
unfortunately I have not so much time to go into great length of explanation. But I will try to make it understandable.
You have to somehow find some literature to understand the BH-diagram. because It is essential for further understanding what is going on.
First: comparison of areas of both curves
Your coil is running idle in both cases. This does not show a real situation. It will be different under load that is current draw by a secondary coil or physical movement towards a pm or away from it.
Second: you do not know where the zero-line is in the second curve because you have the static pre-magnetization left in the core ( after puls off ) due to your pm attached to it. I am sure the curve is above the zero-line, meaning in the positive area of induced voltage. It must be so. If you would remove the pm from your coil after switching off the puls, only then will you see the whole picture.
But this is impossible to to.
If you look at the pic I attached to my post , the full BH diagram is the dynamic path of sinuswave-current flowing in the coil. For a DC-Puls - as you have applied it - only that part of the curve is valid which is above the horizontal zero-line ( Middle diagram) As the fieldstrength rises ( Ampere Turns per Meter ) while the puls increases the current in the coil so does the induced Voltage per second = B. It rises steep first and enters the saturation-area where the curve gets more flat.
If puls is cut off the the upper left part of the BH-curve is valid. At that time current from your puls-generator stops and the magnetic field collapses creating the negative spike. So the current you had to spent is 230 mA as you stated. You have not spent current for reversal of magnetization because you just stopped the current while an ac-current would continue to demagnetize to zero and further on to the negative side consuming more power
Now if you magnetize your core with a permanent-magnet the BH-curve starts at the level of the arrows either in the positive side ( above the horizontal level) or the negative side depending on the pm-pole facing your coil. Lets assume your pre-magnetization has shifted the level above zero. Then this means your puls-current starts here and does not have to magnetize up to this arrow- level in the first place thus not using so much current. You reach the saturation level with less current.
As I said before symmetric pre-magnetization like you did in a torus-core will bring about a different behavior than in a solenoid which is magnetized along its axis. It can not be compared.
For any valid test you have to repeat this pre-magnetization and pulsing using a solenoid which is at the same time moving by another magnet, as in the muller device
It does not make sense this way â€" of course depending if you like to find something out about muller-principle or some basics about torus-core-coils with different materials.
Regards
Kator01
Quote from: gotoluc on September 08, 2011, 09:16:43 PM
Hi Dave, thanks for posting your additional comments and new test results.
I'll try again to see if I can get a small Inductance change in the FERROXCUBE.
Concerning the current drop when the core is biased. You believe there is an inductance gain! ... how interesting. Kator01 says there is no Inductance gain. I don't know what an Inductance gain would look like on the scope. So I started this topic to see if anyone has the answers. So far we have a split.
Not sure why you ask "does the inductance remain high when you remove the bias magnet?"
I think the answer is no but I show the differences in the video (with and without magnet)
Thanks for sharing
Luc
Hi Luc
Will try and explain again what is happening which causes a reduction in current.It is called Inductive Reactance.I suggest you study this ,read the bit inductive reactance.http://www.ndt-ed.org/EducationResources/CommunityCollege/EddyCurrents/Physics/selfinductance.htm
With your core you are increasing the permability which increases the inductance.
You can test this with a Air coil.Take one Air coil connect to a function generator use some frequency and connect in series with a current meter,note the current then insert a piece of
ferrite rod and you will see a current reduction Caused by more reactive current.
Lenz`s Law ,or "For every action there is a equal and opposite reaction" Which opposes the primary current.
Regards Dave
Quote from: Kator01 on September 09, 2011, 11:34:16 AM
Hi Luc,
unfortunately I have not so much time to go into great length of explanation. But I will try to make it understandable.
You have to somehow find some literature to understand the BH-diagram. because It is essential for further understanding what is going on.
First: comparison of areas of both curves
Your coil is running idle in both cases. This does not show a real situation. It will be different under load that is current draw by a secondary coil or physical movement towards a pm or away from it.
Second: you do not know where the zero-line is in the second curve because you have the static pre-magnetization left in the core ( after puls off ) due to your pm attached to it. I am sure the curve is above the zero-line, meaning in the positive area of induced voltage. It must be so. If you would remove the pm from your coil after switching off the puls, only then will you see the whole picture.
But this is impossible to to.
If you look at the pic I attached to my post , the full BH diagram is the dynamic path of sinuswave-current flowing in the coil. For a DC-Puls - as you have applied it - only that part of the curve is valid which is above the horizontal zero-line ( Middle diagram) As the fieldstrength rises ( Ampere Turns per Meter ) while the puls increases the current in the coil so does the induced Voltage per second = B. It rises steep first and enters the saturation-area where the curve gets more flat.
If puls is cut off the the upper left part of the BH-curve is valid. At that time current from your puls-generator stops and the magnetic field collapses creating the negative spike. So the current you had to spent is 230 mA as you stated. You have not spent current for reversal of magnetization because you just stopped the current while an ac-current would continue to demagnetize to zero and further on to the negative side consuming more power
Now if you magnetize your core with a permanent-magnet the BH-curve starts at the level of the arrows either in the positive side ( above the horizontal level) or the negative side depending on the pm-pole facing your coil. Lets assume your pre-magnetization has shifted the level above zero. Then this means your puls-current starts here and does not have to magnetize up to this arrow- level in the first place thus not using so much current. You reach the saturation level with less current.
As I said before symmetric pre-magnetization like you did in a torus-core will bring about a different behavior than in a solenoid which is magnetized along its axis. It can not be compared.
For any valid test you have to repeat this pre-magnetization and pulsing using a solenoid which is at the same time moving by another magnet, as in the muller device
It does not make sense this way â€" of course depending if you like to find something out about muller-principle or some basics about torus-core-coils with different materials.
Regards
Kator01
Thanks Kator01 for taking the time to better explain this.
It is beginning to make more sense! I'll let it digest for some time and reread again later.
Thanks for sharing
Luc
Quote from: firlight on September 09, 2011, 11:43:03 AM
Hi Luc
Will try and explain again what is happening which causes a reduction in current.It is called Inductive Reactance.I suggest you study this ,read the bit inductive reactance.http://www.ndt-ed.org/EducationResources/CommunityCollege/EddyCurrents/Physics/selfinductance.htm
With your core you are increasing the permability which increases the inductance.
You can test this with a Air coil.Take one Air coil connect to a function generator use some frequency and connect in series with a current meter,note the current then insert a piece of
ferrite rod and you will see a current reduction Caused by more reactive current.
Lenz`s Law ,or "For every action there is a equal and opposite reaction" Which opposes the primary current.
Regards Dave
Hi Dave, thanks for posting your explanation.
It is very simple. I don't need to test an air core coil and adding a core to see the effect as I know the current will drop. However, I find it interesting that you seem to be saying the PM is raising the cores permeability therefore we have a drop in current.
Kator01 explanation seems to be quite different!
Interesting
Thanks for sharing
Luc
Hey Luc
I think the answer as to how and why is more complicated than just saying it increases inductance. To test, run a slow freq sweep to the coil, no magnet , then sweep with the mag, and watch the scope. There may be differences at different freq than just measuring a larger inductor.
Have you tried the magnet to the outside of the core, like I did on the orbonbon? I even had multiple mags on the outer core that gave it an advantage for different configs.
Good to see ya back in action. ;]
Mags
Quote from: Magluvin on September 09, 2011, 08:16:04 PM
Hey Luc
I think the answer as to how and why is more complicated than just saying it increases inductance. To test, run a slow freq sweep to the coil, no magnet , then sweep with the mag, and watch the scope. There may be differences at different freq than just measuring a larger inductor.
Have you tried the magnet to the outside of the core, like I did on the orbonbon? I even had multiple mags on the outer core that gave it an advantage for different configs.
Good to see ya back in action. ;]
Mags
Hi Mags,
thanks for dropping in a line.
Inductors sure have all kinds of interesting characteristics ;D
I'll play around with it and see if I can make a bonbon ;)
The magnet on the outer of the toroid does not do much, so position is important. It's at its best in the center of the toroid but not penetrating the opening.
Luc
Quote from: gotoluc on September 08, 2011, 10:47:32 AM
...
I have this model of FERROXCUBE: http://uk.farnell.com/jsp/search/productdetail.jsp?SKU=3057010
However, I tried it before starting this topic and a magnet does not boost its Inductance. So I cannot accept your conclusion at this point that this happens in Square Loop cores. Something is different with the Finemet core.
...
Hi Luc,
Reading back last weeks posts I notice your link above shows a 3E5 material type core which has no square loop curve... so maybe this explains why you have not got increase in inductance with it?
Dave referred to 3R1 material type that has square loop curve, Farnell has it:
http://uk.farnell.com/ferroxcube/tn23-14-7-3r1/ferrite-core-toroid-3r1-24mm/dp/179443
They have with OD 36 mm too but at a much higher price:
http://uk.farnell.com/ferroxcube/tn36-23-15-3r1/ferrite-core-toroid-3r1-37mm/dp/179444
Gyula
Quote from: gyulasun on September 12, 2011, 06:31:50 PM
Hi Luc,
Reading back last weeks posts I notice your link above shows a 3E5 material type core which has no square loop curve... so maybe this explains why you have not got increase in inductance with it?
Dave referred to 3R1 material type that has square loop curve, Farnell has it:
http://uk.farnell.com/ferroxcube/tn23-14-7-3r1/ferrite-core-toroid-3r1-24mm/dp/179443
They have with OD 36 mm too but at a much higher price:
http://uk.farnell.com/ferroxcube/tn36-23-15-3r1/ferrite-core-toroid-3r1-37mm/dp/179444
Gyula
Thanks for looking at the topic and posting your reply Gyula
I thought these ferroxcube were the same other than size. I'm not going to buy more just to see if Dave is right. Also his Inductance gain was minimal so I don't know why it would be worth it.
What do you think of the Finemet test I did? do you see anything worth testing any further?
Do you agree with Kator01 explanation?
Do you agree with Dave's explanation?
Do you have your own explanation?
Do you think I should take apart the Finemet toroid tape and cut strips to make a solenoid style coil as Kator1 suggests to test it as motor or generator coil?
Sorry for all the questions but I need a little help on which direction to take next :P
Thanks for sharing
Luc
Quote from: gotoluc on September 13, 2011, 10:47:55 AM
Thanks for looking at the topic and posting your reply Gyula
I thought these ferroxcube were the same other than size. I'm not going to buy more just to see if Dave is right. Also his Inductance gain was minimal so I don't know why it would be worth it.
What do you think of the Finemet test I did? do you see anything worth testing any further?
Do you agree with Kator01 explanation?
Do you agree with Dave's explanation?
Do you have your own explanation?
Do you think I should take apart the Finemet toroid tape and cut strips to make a solenoid style coil as Kator1 suggests to test it as motor or generator coil?
Sorry for all the questions but I need a little help on which direction to take next :P
Thanks for sharing
Luc
Hi Luc
Why don`t you use your toroid as a pulse motor driver they don`t half
motor you can get up to 10000 rpm no problem,use it edge on.
Regards Dave
Quote from: firlight on September 13, 2011, 04:54:23 PM
Hi Luc
Why don`t you use your toroid as a pulse motor driver they don`t half
motor you can get up to 10000 rpm no problem,use it edge on.
Regards Dave
Hi Dave,
not sure I know what you mean by "they don`t half
motor" and "use it edge on"
Can you post more details, illustration or link so I can see what it looks like.
Thanks for sharing
Luc
Quote from: gotoluc on September 13, 2011, 10:57:31 PM
Hi Dave,
not sure I know what you mean by "they don`t half
motor" and "use it edge on"
Can you post more details, illustration or link so I can see what it looks like.
Thanks for sharing
Luc
Hi Luc
English slang sorry! "Dont half motor" means moves fast,speeds up.
have to go to the dentist now,will post pic later.
regards Dave
Here is pic of toroid motor looking down edge of toroid facing magnets on rotor.
Quote from: gotoluc on September 13, 2011, 10:47:55 AM
I thought these ferroxcube were the same other than size. I'm not going to buy more just to see if Dave is right. Also his Inductance gain was minimal so I don't know why it would be worth it.
Hi Luc,
Ok on the above quote, I meant to explain why the L did not increase for your 3E5 material (Dave has 3R1 material), that is all.
Quote
What do you think of the Finemet test I did? do you see anything worth testing any further?
Do you agree with Kator01 explanation?
Do you agree with Dave's explanation?
Do you have your own explanation?
Do you think I should take apart the Finemet toroid tape and cut strips to make a solenoid style coil as Kator1 suggests to test it as motor or generator coil?
Sorry for all the questions but I need a little help on which direction to take next :P
Well, I think the inductance really increases for the Finemet core in your setup shown in the video. The scopeshots can be explained as follows:
The moment you switch off the current in the magnetless case, it behaves as it should, the collapsing field induces a voltage with opposite polarity than the input voltage to the coil and then this changing voltage excites the LC circuit where L is your Finemet coil of 7.8mH or so and C is the stray and self capacitance of the coil. Because there is no any load across the the coil (except your scope probe) the voltage spike rings down as usual, its oscillating frequency is defined by L and C, and mainly coil losses dissipate the energy of this LC tank it got from the collapsing field.
Now on the scope shot with the magnet: the same happens at switchoff as before but there are two significant differences.
First, the input current is much less into the coil (as you measured it too) due to the nearly 4 times as high L value (due to the 4 times higher inductive reactance of L).
Second, the LC tank circuit has a much lower self resonance frequency than in the magnetless case, also due to the increased L. This involves the ring down frequency is at a lower frequency now and this is why the scope shot shows a wider curve. AND the lower spike's amplitude for the higher L comes from the much less input current: the energy content of the collapsing field is also less of course.
At the moment, all I could suggest is to somehow test the alleged Orbo principle: introduce a certain input current into the coil with its Finemet core and arrange for a permanent magnet to appear the moment the input current is switched off in the coil, then the collapsing field "should see" a nearly 4 times as high L inductance than the input current "saw". I am not saying this gives energy gain, just a possibility... To make the appearence of the permanent magnet motionless, I would suggest using an enhanced electromagnet (in front of the Finemet core), suggested by DMMPOWER here:
http://www.overunity.com/index.php?topic=4624.msg96814#msg96814
This electromagnet adds together the flux of a permanent and that of an electromagnet. placing your two Finemet cores in front and behind of such electromagnet helps utilize the output flux at both of its ends.
rgds, Gyula