Storing Cookies (See : http://ec.europa.eu/ipg/basics/legal/cookies/index_en.htm ) help us to bring you our services at overunity.com . If you use this website and our services you declare yourself okay with using cookies .More Infos here:
https://overunity.com/5553/privacy-policy/
If you do not agree with storing cookies, please LEAVE this website now. From the 25th of May 2018, every existing user has to accept the GDPR agreement at first login. If a user is unwilling to accept the GDPR, he should email us and request to erase his account. Many thanks for your understanding

User Menu

Custom Search

Author Topic: Rotating Magnetic Field's and Inductors.  (Read 177944 times)

tinman

  • Hero Member
  • *****
  • Posts: 5365
Re: Rotating Magnetic Field's an Inductors.
« Reply #15 on: December 15, 2015, 05:56:00 AM »
The word "timing" does not only mean frequency and the time when a pulse begins (like the timing of a spark in a gasoline engine) - in electronics it also means how the entire signal varies in time and how it varies in time compared to other signals.

I am sure MH meant the above.

I have no idea what MH meant, his statement makes no sense. The current trace shows the current starts to flow at the same time, and stops at the same time. The amplitude of the wave changes simply because the current value changes in the two different cases. Now why dose that current value change?--what causes the current increase? , thats right, the removal of the magnets. MH says that I should just believe he is right--> are you serious?. MH says its all down to timing, without explaining what he means about timing,-then says -just believe me, as im right. This is comedy at it's best-thats what that is.


Brad

tinman

  • Hero Member
  • *****
  • Posts: 5365
Re: Rotating Magnetic Field's and Inductors.
« Reply #16 on: December 15, 2015, 06:04:25 AM »
Hi Brad,

I really enjoyed that video.  It is interesting.  I can think of one thing that might explain some of the effect you are seeing.  I do believe the moving magnets are playing an important part in what you are seeing.  I think because they are alternating they are helping to put some power back into the coil.  I also think the presence of the magnet when the coil is turned on probably affects the impedance of the coil causing it to use less current.  Just some random ideas from working with coils and magnets.  Keep up the good work.

Carroll

Yes, I have set the duty cycle so as the inductor just reaches the point of field saturation, and this is when the transistor is opened. Unlike MH's statement, this is the optimal pulse duration for this particular inductor-the best timing you could have as far as an on time for thevinductor go's. Any less time, and the magnetic field dosnt reach maximum amplitude--any longer, and you start to produce unnecessary heat--wasted power, while the magnetic fied gain no more amplitude.

Brad

EMJunkie

  • Hero Member
  • *****
  • Posts: 3322
Re: Rotating Magnetic Field's and Inductors.
« Reply #17 on: December 15, 2015, 07:01:16 AM »
Yes, I have set the duty cycle so as the inductor just reaches the point of field saturation, and this is when the transistor is opened. Unlike MH's statement, this is the optimal pulse duration for this particular inductor-the best timing you could have as far as an on time for thevinductor go's. Any less time, and the magnetic field dosnt reach maximum amplitude--any longer, and you start to produce unnecessary heat--wasted power, while the magnetic fied gain no more amplitude.

Brad


Brad,

An Inductor will take 5 Time Constants to charge to 99.3% of its Current Carrying Capacity. Why they chose 99.3% I don't know. This is sometimes conflicting, 99.3 and 99.7 are common numbers for the same thing. Many sites conflict on this actual number. I got 99.3% from an old Steinmetz Book and stuck with that.

This can be calculated: T = L / R

Where:
T = One Time Constant,
L is Inductance,
and R is of course Resistance.

This curve can be seen on your CSR as a Current Curve. Peak Current is 100% and is seen as a Flat Line for the period of On Time after the 5 Time constants have completed. To give you an idea, the below picture shows approximately 99.3% - It is interesting to note: In a pulsed System, the Magnetic Field is no longer changing in Time after this point! It is very likely that it is not much use to have any On Time past this Time in some systems. However, not always the case though.

There is a Frequency to this time as you can see. In some Systems, a longer On Time is just wasting Power. The Grey Rectangle represents this Time that you may not want to keep the Applied Voltage High.

   Chris Sykes
       hyiq.org

Magluvin

  • Hero Member
  • *****
  • Posts: 5884
Re: Rotating Magnetic Field's and Inductors.
« Reply #18 on: December 15, 2015, 07:01:47 AM »
It looks like one of the scope shots that is with the rotor is showing the rotor producing some generating in the waveform.  Im not sure i understand all of the stepping in the waveform without the rotor.

Mags

Magluvin

  • Hero Member
  • *****
  • Posts: 5884
Re: Rotating Magnetic Field's and Inductors.
« Reply #19 on: December 15, 2015, 07:12:01 AM »
Yes, I have set the duty cycle so as the inductor just reaches the point of field saturation, and this is when the transistor is opened. Unlike MH's statement, this is the optimal pulse duration for this particular inductor-the best timing you could have as far as an on time for thevinductor go's. Any less time, and the magnetic field dosnt reach maximum amplitude--any longer, and you start to produce unnecessary heat--wasted power, while the magnetic fied gain no more amplitude.

Brad

One thing on saturation of the coils core and magnets....

If a core is magnetically biased opposing the field made by the coil, saturation point of the core becomes higher than without the magnetic bias from the rotor. If the magnet is in attraction with the coil, the coils core will saturate much sooner than without the magnetic bias from the rotor.

I suppose that is why Bedini most always had used repulsion from coil to rotor magnet.

There are companies that make magnetic biased inductor/transformer cores. It allows for more storage in the core before saturation vs a core that is not magnetically biased.

Mags

EMJunkie

  • Hero Member
  • *****
  • Posts: 3322
Re: Rotating Magnetic Field's and Inductors.
« Reply #20 on: December 15, 2015, 07:23:28 AM »


Nice Video too!!!

Induction, Time Rate of Change of the Magnetic Field in the proximity of a Conductor. Little bit of both emf = Bvl and also emf = dPhi/dt all there I would say.


   Chris Sykes
       hyiq.org

tinman

  • Hero Member
  • *****
  • Posts: 5365
Re: Rotating Magnetic Field's and Inductors.
« Reply #21 on: December 15, 2015, 10:50:04 AM »
It looks like one of the scope shots that is with the rotor is showing the rotor producing some generating in the waveform. Im not sure i understand all of the stepping in the waveform without the rotor.

Mags

You mean as the scope shot below show's.
I would say that my FG is unable to supply enough current to the base of the transistor to switch it on hard enough when the current reaches a certain level flowing through the collector/emitter junction-->maybe we could call this transistor slip lol.. If the transistor is switched on hard enough,then the voltage across the collector/emitter should be zero during on time--either that,or the transistor is not so good anymore  :D. I would be better off using a mosfet,which i will be changing to from now on.

But that is just a guess.


Brad

verpies

  • Hero Member
  • *****
  • Posts: 3473
Re: Rotating Magnetic Field's and Inductors.
« Reply #22 on: December 15, 2015, 11:48:42 AM »
An Inductor will take 5 Time Constants to charge to 99.3% of its Current Carrying Capacity. Why they chose 99.3% I don't know. This is sometimes conflicting, 99.3 and 99.7 are common numbers for the same thing.
It is 99.32620530% because 1 - (1/e5) is that much

Also, it should not be called a "Current Carrying Capacity" but a V/R limit - a consequence of the Ohm's Law.
The V/R limit is a completely different concept than the core saturation limit.
It is all described in detail here.


tinman

  • Hero Member
  • *****
  • Posts: 5365
Re: Rotating Magnetic Field's and Inductors.
« Reply #23 on: December 15, 2015, 02:04:07 PM »
With a few minor adjustments,we have managed to increase the efficiency even further.
I have the duty cycle set spot on now,and not only did that decrease the P/in (as it would),it also increased the P/out.

So now it is time to put it together as a pulse motor,where we will now use the trigger coil to fire the transistor. Lets see if we can break the 50% efficiency barrier as far as electrical P/in and P/out go's.


Brad

https://www.youtube.com/watch?v=4leXKDz7D8c

tinman

  • Hero Member
  • *****
  • Posts: 5365
Re: Rotating Magnetic Field's and Inductors.
« Reply #24 on: December 15, 2015, 02:56:34 PM »
Below are the two scope shots that are from the last video(post above),along with the P/in P/out calculations.


P/in with rotor is
180mA @ 12.47v = 2.246 watts
P/out is 74mA @ 12.48v
Efficiency is 41.22%

P/in without rotor
240mA @ 12.47v
P/out is 12.49v @ 74mA = 2.992 watts
Efficiency is 30.88%

Once again-with the duty cycle set at optimum coil performance,the rotor and spinning magnets increased the efficiency by 10.34%.


Brad

tinman

  • Hero Member
  • *****
  • Posts: 5365
Re: Rotating Magnetic Field's and Inductors.
« Reply #25 on: December 15, 2015, 03:18:49 PM »
In the video below,i have hooked up the trigger coil,and now am running the DUT as a pulse motor.

Straight off the bat,we have smashed the 50% efficiency barrier,as far as electrical P/in and P/out go's. In fact,we have beaten the 60% efficiency barrier<--how's them apples MH,much more than the 30% you once claimed to be about the limit.

P/in
200mA @ 12.49v = 2.498 watts
P/out
119mA @ 12.69v = 1.51 watts.

Electrical efficiency = 60.45%

https://www.youtube.com/watch?v=zTf4Bl79NZk


Brad

EMJunkie

  • Hero Member
  • *****
  • Posts: 3322
Re: Rotating Magnetic Field's and Inductors.
« Reply #26 on: December 15, 2015, 09:07:35 PM »
It is 99.32620530% because 1 - (1/e5) is that much

Also, it should not be called a "Current Carrying Capacity" but a V/R limit - a consequence of the Ohm's Law.
The V/R limit is a completely different concept than the core saturation limit.
It is all described in detail here.


Thanks Verpies!!!

Yes I used the wrong term, V/R limit, simply because the Applied Voltage determines the Current because of R. Higher the Applied Voltage the Higher the Current will go. As you point out, this is Ohms Law.

Thank You for correcting this!

   Chris Sykes
       hyiq.org

gotoluc

  • elite_member
  • Hero Member
  • ******
  • Posts: 3096
Re: Rotating Magnetic Field's and Inductors.
« Reply #27 on: December 16, 2015, 12:27:14 AM »
Here you go mate, a second party confirmation with a suggestion how to further boost your results.

Link to video demo: https://www.youtube.com/watch?v=TwKd7UG1Wb8

Enjoy ;)

Luc

verpies

  • Hero Member
  • *****
  • Posts: 3473
Re: Rotating Magnetic Field's and Inductors.
« Reply #28 on: December 16, 2015, 01:28:56 AM »
Yes I used the wrong term, V/R limit, simply because the Applied Voltage determines the Current because of R. Higher the Applied Voltage the Higher the Current will go. As you point out, this is Ohms Law.
...and on the scope the V/R limit and the core saturation look like this:

verpies

  • Hero Member
  • *****
  • Posts: 3473
Re: Rotating Magnetic Field's and Inductors.
« Reply #29 on: December 16, 2015, 01:34:20 AM »
Here you go mate, a second party confirmation with a suggestion how to further boost your results.
Link to video demo: https://www.youtube.com/watch?v=TwKd7UG1Wb8
Yes, keeping the low resistance of the coil and wiring is very important.

Keeping the "resistance" of the recovery capacitor as low as possible, is very important, too.
The trick is that a discharged capacitor has lower "resistance" than a charged capacitor.  This is the reason why a discharged capacitor is a better receiver of the "inductive spike" than a charged capacitor.  This is also the reason why the capacitor should be emptied before each "spike" for the most efficient energy recovery*

The third method to increase efficiency is to keep the coil's ON pulse time below its Tau constant (L/R).


Cheers

*MH & TK - please do not admonish me for this colloquiality - I know that the ESR does not change and I know how to analyze that decreasing current of a charging capacitor in a proper technical jargon, but I'm trying to simplify the vernacular as much as possible.