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Author Topic: The Non-Sense Pulse Motor.  (Read 83466 times)

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Ok,so i was thinking about this some more,and i believe there would be a benefit in putting a slot along the length of the steel tube,so as it is not seen as a shorted turn.

At these low RPM,it may not have much effect,but every bit helps.

So if you have not built your drive coil yet,it may be something to consider ?


Brad

Just thinking, if it were not a slit tube, it could act as a shorted turn to the magnets on the rotor when they go by?

Mags
   

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Just thinking, if it were not a slit tube, it could act as a shorted turn to the magnets on the rotor when they go by?

Mags

That is what i was refering  to when i said-at these low RPM. O0


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It's not as complicated as it may seem...
What if it was just a solid iron core? Would it also be seen as a shorted turn by the rotor magnets?
   

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What if it was just a solid iron core? Would it also be seen as a shorted turn by the rotor magnets?
We can print any shape. If solid, same diameter all the way? Are there better structures that open up with 3D Printing iron PLA.Seems ferrite (non-conductive) like chacteristics. soft iron particles suspended in PLA.
   

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What if it was just a solid iron core? Would it also be seen as a shorted turn by the rotor magnets?

It would be seen as just a short,which would result in eddy current heating of the solid core.

The joule energy value of heat produced will be equal to the required energy to move the magnets past the core.


Brad


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It would be seen as just a short,which would result in eddy current heating of the solid core.

The joule energy value of heat produced will be equal to the required energy to move the magnets past the core.


Brad
Speaking of shorted coils, just realised that the bobbin I wound as the drive coil uses Copper PLA as the keepers which I thought was copper in colour only.... doh!
   

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Speaking of shorted coils, just realised that the bobbin I wound as the drive coil uses Copper PLA as the keepers which I thought was copper in colour only.... doh!

Hey Jim

Well Id try to put a meter to it. I dont suspect that the copper particles in the pla are all in physical contact to cause a problem. I believe there is more plastic involved than the metals it contains. could probably judge that by weighing the impregnated pla in comparison with the real deal, both having the same volume for the comparison, and even make the comparison with just raw pla to see the difference between it and the metalic pla. It would give you a good idea of the differences. Had messed with iron powders and resins. Its never as good magnetically as say a ferrite or solid magnetic metals. even tried super thin CA glue, hoping it would just soak in without increasing the distance between particles. The CA wouldnt soak in, like water on oil. Just seems better to use the real thing. The best I could do was thin resin and mixing till it was a stiff mud. But still doesnt compare to solid iron or ferrites, of which are a compressed and baked if I remember correctly.

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Thanks Mags, interesting. I've been reading up on powdered cores and their limitations in tranformers due to their round loop soft saturation characteristics. I'll b e testing different structures though, as the research I've read involves solid powdered cores. I'm thinking different infill structrures may create more complex paths for the flux resulting hopefully sharper saturation. I'm probably completely wrong but hey, won't stop me trying :) I would have thought I would see eddy currents though in a copper powered core like my bobin keeper. I thing my iron pla is up around 80% not sure about the copper. There's another which is up around 95% so I'll be getting some of that soon.
   

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Scope dramas still with CVR2  C.C

https://www.youtube.com/watch?v=7FIty_SgbZI


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Scope dramas still with CVR2  C.C

https://www.youtube.com/watch?v=7FIty_SgbZI

Damn I need a new scope?
   

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It's not as complicated as it may seem...
Thanks for the video Brad! (and thanks for not rubbing in your DMM results).

I am surprised indeed that the AVG measurements in the CVR's aren't the same.  >:( I don't have an explanation as to why.

Regarding the scope/meter discrepancy for a moment, what is the AVG CSR2 voltage by manual calculation?

If we assume that you are seeing about 750mVp across CSR2 and using a 5% duty, that would calculate to 37.5mV AVG. This is lower than your meters were indicating, and right around what the scope is saying.  :o

In either case, you are measuring more AVG current in CSR2 than in CSR1, so something is different there.

If you have indeed managed to extract some energy from the magnet, perhaps you might consider pausing at this time and investigating further to see if a SS device is possible.
   
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Perhaps doing a differential measurement with two probes across the CSR2 could shed some more lights on the voltage amplitude (just to widen the measuring possibilities). 

Gyula
   

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Thanks for the video Brad! (and thanks for not rubbing in your DMM results).

I am surprised indeed that the AVG measurements in the CVR's aren't the same.  >:( I don't have an explanation as to why.

Regarding the scope/meter discrepancy for a moment, what is the AVG CSR2 voltage by manual calculation?

If we assume that you are seeing about 750mVp across CSR2 and using a 5% duty, that would calculate to 37.5mV AVG. This is lower than your meters were indicating, and right around what the scope is saying.  :o

In either case, you are measuring more AVG current in CSR2 than in CSR1, so something is different there.

If you have indeed managed to extract some energy from the magnet, perhaps you might consider pausing at this time and investigating further to see if a SS device is possible.

ATM,i am still not 100% sure about the DMM reading--we have to remain open minded.
The scope is what is bugging me. Why dose ch2(CSR1) always give the correct reading,and ch1 on CSR2 always change with the number of cycles displayed on the screen ?.

If the scope is having trouble reading CSR2,then the DMM maybe as well.


Brad


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It's not as complicated as it may seem...
The two wave forms are very different.

The peak-to-average ratio in CSR1 is very low compared to that of CSR2. CSR1 has a high DC initial average already, and the peak amplitudes are on the order of the avg level. CSR2 on the other hand has a 0V DC initial average, with a relatively high/short duration peak, so it is going to be more challenging for any measuring device than CSR1, even though it should be no problem for either the meter or the scope.

What I might suggest is to perform some tests on a few different meters, AND the scope to see when/if they ever agree. Just pipe the FG signal straight in to all at the same time. Keep about 10 to 20 pulses on the scope display, and vary the PW from 1% up to 50% duty. Write down the levels of each at a number of PW's. So that you have minimal variability from the scope's trigger, use the FG output to trigger the scope. That will keep it constant so it can be factored out of the test.
   

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Perhaps doing a differential measurement with two probes across the CSR2 could shed some more lights on the voltage amplitude (just to widen the measuring possibilities). 

Gyula

OK,so how would i go about that?,as in ,my scope and FG share a common ground,and so one probe would then be connected directly to ground,as one side of CSR2 is the ground connection.



Brad


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For differential voltage measurement, you do not need to connect any of gnd clips of the probes to the circuit, they are left floating.  Just attach the two input pins of the two probes across CSR2.  I meant to do separately this measurement for both CSRs

See this video on differential measurement but I think you know it https://www.youtube.com/watch?v=VWodjUSkYVE 

Gyula
   

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 author=poynt99 link=topic=3684.msg71663#msg71663 date=1548597094]

Quote
Thanks for the video Brad! (and thanks for not rubbing in your DMM results).
Regarding the scope/meter discrepancy for a moment, what is the AVG CSR2 voltage by manual calculation?

Quote
If we assume that you are seeing about 750mVp across CSR2 and using a 5% duty, that would calculate to 37.5mV AVG. This is lower than your meters were indicating, and right around what the scope is saying.  :o

In the video,i was using a 7% duty cycle,which gives an average of 52.8mV.
The meter was showing at 46mV.

Quote
I am surprised indeed that the AVG measurements in the CVR's aren't the same.  >:( I don't have an explanation as to why.

Well,if you are interested in my thought's,here they are.

With a standard coil,having a steel or ferrite core,when we send a current through the coil the magnetic field is built from a 0 value up. So we start with no field,and then that field begins to build and cut through the windings as the current begins to flow. When we disconnect the current,the field collapses back through the winding's and the current continues to flow in the !same! direction<--this is important to remember.

Now,when we have a PM as the core we already have a magnetic field that exists through the winding's,but where that field is opposite to that of which the coil will produce once energised.
So now when we energise the coil the existing  field must first collap's through the windings before the opposite field can be built by the induced current through the coil.

Now,the question is-->when the existing PM field is collapsing,which way will the induced current flow?
Well we know that when the current to the coil is cut off,the inductive kickback current keeps flowing in the same direction. This can only mean that the current produced by the collapsing PMs field through the coil must produce a current flow in the opposite direction to that of the induced current.

Why can we see this reversed current?
Well we can,we just dont know we are looking at it via the extra current at CVR2.
One side of CVR2 is X amount above 0,and the other side of CVR2 is X amount below 0,instead of being a 0 value.

It would seem to me that we have two opposite flows of current meeting at CVR2,or the potential across the coil becomes opposite to that of the supply for a brief period of time.

If we look at the scope shot below,how is the inductive kickback period nearly twice as long as the current input time?.

Anyway,they are my thoughts for what there worth.

Quote
In either case, you are measuring more AVG current in CSR2 than in CSR1, so something is different there.

If you have indeed managed to extract some energy from the magnet, perhaps you might consider pausing at this time and investigating further to see if a SS device is possible.

I did post a design for a SS version some pages back on this thread.
I am not sure anyone took up the !theoretical! project?.
Perhaps i will take the time today to give it a shot,while waiting for the rotor to be perfected by Jim.


Brad


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For differential voltage measurement, you do not need to connect any of gnd clips of the probes to the circuit, they are left floating.  Just attach the two input pins of the two probes across CSR2.  I meant to do separately this measurement for both CSRs

See this video on differential measurement but I think you know it https://www.youtube.com/watch?v=VWodjUSkYVE 

Gyula

I understand that Gyula,but my FGs ground is between the two CVRs,and shares a common ground with the scope.
This means that leaving the scope grounds floating makes no difference,as the SGs ground will be attached to the circuit between the two CVRs,and thus the scopes ground will also be attached to the circuit between the two CVRs.

This also means that one of the scopes probes will be attached directly to ground,regardless of whether or not the scopes ground leads are left floating.


Brad


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It's not as complicated as it may seem...
In the video,i was using a 7% duty cycle,which gives an average of 52.8mV.
The meter was showing at 46mV.
OK, that makes sense.

Quote
So now when we energise the coil the existing  field must first collap's through the windings before the opposite field can be built by the induced current through the coil.

Now,the question is-->when the existing PM field is collapsing,which way will the induced current flow?
Well we know that when the current to the coil is cut off,the inductive kickback current keeps flowing in the same direction. This can only mean that the current produced by the collapsing PMs field through the coil must produce a current flow in the opposite direction to that of the induced current.
In terms of the collapsing field and direction of current, I don't think anything changes with the magnet scenario, other than the core is pre-biased with flux in the opposite direction the coil is going to take it when it is energized. Since the PM field is static, as far as the coil is concerned it is starting off at "0" so to speak. So the prebias allows for more flux swing, in theory twice the amount. There may also be a commensurate increase in the average current in CSR2.

Quote
If we look at the scope shot below,how is the inductive kickback period nearly twice as long as the current input time?.
The length of IK time is not the relevant issue; it can be shorter or longer than the ON time of the switch. The important question is: is the energy in the ON phase and IK phase roughly equal? I think you can do a rough calculation on the IK phase to see if the area under each curve is equal (of course there will be some losses).

Quote
I did post a design for a SS version some pages back on this thread.
I am not sure anyone took up the !theoretical! project?.
Perhaps i will take the time today to give it a shot,while waiting for the rotor to be perfected by Jim.


Brad
Yes I saw that SS idea way back too, but I guess no one ran with it yet. Looking forward to your next video on it.
   

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 author=poynt99 link=topic=3684.msg71686#msg71686 date=1548646601]

Quote
In terms of the collapsing field and direction of current, I don't think anything changes with the magnet scenario, other than the core is pre-biased with flux in the opposite direction the coil is going to take it when it is energized. Since the PM field is static, as far as the coil is concerned it is starting off at "0" so to speak. So the prebias allows for more flux swing, in theory twice the amount. There may also be a commensurate increase in the average current in CSR2.

Well lets have a good think about this.
We agree that there is a static field from the PM core cutting through the coil windings-yes?
Now,the coil produces a magnetic field that is opposite that of the PM field.
In order to induce a current through the coil,the magnetic field must change with time.
Would you not agree that when a small amount of current flows through the coil,the PMs field through the windings will change with time. So the PMs field must be removed from the coil windings before the opposite induced magnetic field from the coil can cut through the windings.

Please know that this is only my understanding,and could quite easily be incorrect.


Brad


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author=poynt99 link=topic=3684.msg71663#msg71663 date=1548597094]



I did post a design for a SS version some pages back on this thread.
I am not sure anyone took up the !theoretical! project?.
Perhaps i will take the time today to give it a shot,while waiting for the rotor to be perfected by Jim.


Brad

Sure, been tinkering with some ideas. Still waiting to turn out a decent print on my machine. Just watching they way it prints though some of the threads may need a bees dick more centring. Wishing there was a Permalloy filament now too :) EDIT : Successful print yay
« Last Edit: 2019-01-29, 05:21:52 by JimBoot »
   

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It's not as complicated as it may seem...
author=poynt99 link=topic=3684.msg71686#msg71686 date=1548646601]

Well lets have a good think about this.
We agree that there is a static field from the PM core cutting through the coil windings-yes?
Now,the coil produces a magnetic field that is opposite that of the PM field.
In order to induce a current through the coil,the magnetic field must change with time.
Would you not agree that when a small amount of current flows through the coil,the PMs field through the windings will change with time. So the PMs field must be removed from the coil windings before the opposite induced magnetic field from the coil can cut through the windings.

Please know that this is only my understanding,and could quite easily be incorrect.


Brad
The way I see it is:

- The polarization of the field from the core/coil/magnet will decrease then change polarity through the process.
- Pre-bias allows one to utilize the full B-H curve of the core, rather than only half.
- All else remains the same.

I might try to play with a saturable core in spice and see where that goes.
   

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The way I see it is:

- The polarization of the field from the core/coil/magnet will decrease then change polarity through the process.


During this decrease,will a current be induced through the windings that adds to the current flowing through the windings that causes the decrease in the first place?.

I
Quote
might try to play with a saturable core in spice and see where that goes.

I would be interested in seeing your results from that  O0


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I made a similar magnet cored coil as Brad uses, and redid my tests.

I have 10  5mm / 12mm ceramic magnets stacked together isolated by PVC tubing and a steel tube with a slot over it.
A coil wiht about 200 turns in 3 layers (0.7mm) was wound around this, measuring 1.3mH and 0.8 Ohm.

Same circuit as before, C1 10000uF, C2 470uF, UF4007 diode, power led, IRF530 MOSFET, 100 Ohm gate resistor,
CSR1 and CSR2 1 Ohm 1% inductionfree resistors.

Battery operated FG running at 86Hz square wave (DC) at 7% duty cycle.

Result is still that both CSR's have the same average current going through them measured by DMM's and the scope.

Not sure if Brad still uses a transistor or MOSFET.

 
Video here:  https://www.youtube.com/watch?v=s1FlYIm-4FE


Itsu
   

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i used my magneto sensor (MLX90393) to sense/show the magnetic field of the BMCC (Brad Magnet Cored Coil).

The FG frequency was lowered to 1Hz @ 6% duty cycle.

It seems to work nicely allthough somehow the flipovers stall for some time, then continues again.
Guess the caps need to be filled up faster.

The magneto sensor and application was discussed here:
http://www.overunityresearch.com/index.php?topic=3588.msg70836#msg70836


Video here:  https://www.youtube.com/watch?v=kGftPqiOTTI

   
Itsu
   
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