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News announcements and other topics => News => Topic started by: DeepCut on January 24, 2011, 08:15:41 AM

Title: Some interesting transformer experiments ...
Post by: DeepCut on January 24, 2011, 08:15:41 AM
http://www.youtube.com/user/Raselli1#p/u

Gary.
Title: Re: Some interesting transformer experiments ...
Post by: SchubertReijiMaigo on January 24, 2011, 01:10:26 PM
Very interesting --> pulsed DC transfomer, Kunel patent, Leedskalin PMH, variable reluctance phemomena in action !!!
Note: the experimenter use Ammeter not a digital, to reduce measurement errors due to the spike and square pulse.
Title: Re: Some interesting transformer experiments ...
Post by: the_big_m_in_ok on January 24, 2011, 03:52:51 PM
Quote from: SchubertReijiMaigo on January 24, 2011, 01:10:26 PM
Very interesting --> pulsed DC transfomer, Kunel patent, Leedskalin PMH, variable reluctance phemomena in action !!!
Note: the experimenter use Ammeter not a digital, to reduce measurement errors due to the spike and square pulse.
You're right.  It was analog, with a needle that pivoted.

The needle didn't move much, but it wasn't a very big light bulb, either.  Maybe his next experiment could use a bifilar wound coil?

--Lee
Title: Re: Some interesting transformer experiments ...
Post by: Nali2001 on January 26, 2011, 03:57:16 AM
Interesting thing is also, what (and how) is causing the output in transformers if you think about? In generators we want the fields of the magnets to 'cut' the coils. Or wipe the magnetic field over the coil, you know good magnetic interaction. But in transformers 95% of the field is contained in the core all the time and still the secondary 'generates' an output just fine. And in the video there is a huge distance from core to coil. So the secondary coil is not exposed to any magnetic field at all. Well maybe some 1% leak magnetism but still food for thought.

Video:
http://www.youtube.com/watch?v=XsrbaCJo3Qw&feature=related (http://www.youtube.com/watch?v=XsrbaCJo3Qw&feature=related)

Title: Re: Some interesting transformer experiments ...
Post by: mikestocks2006 on January 26, 2011, 01:54:25 PM
Quote from: DeepCut on January 24, 2011, 08:15:41 AM
http://www.youtube.com/user/Raselli1#p/u

Gary.
Hi Gary, Nali2001, interesting videos ,thx for posting.

In these experiments, from the same person,
Part1 http://www.youtube.com/user/Raselli1#p/u/5/SHbQXnXK6Xc
and Part2 http://www.youtube.com/user/Raselli1#p/u/4/BsN2sr3U0PY

It would also be interesting to see the behavior if the cores are made of non electricaly conductive material, eg soft ferrite. Is it the grain domain orientation, electric conductivity or both?
Title: Re: Some interesting transformer experiments ...
Post by: exnihiloest on January 27, 2011, 03:49:47 AM
Quote from: Nali2001 on January 26, 2011, 03:57:16 AM
...
But in transformers 95% of the field is contained in the core all the time and still the secondary 'generates' an output just fine.
...

It doesn't work this way.
The field is not permanently contained in the core. It enters and escapes, crossing the core:
A field is generated around a conductor carrying current. The field lines appear as circles around a conductor when current is flowing. These circles grow and expand when the current is increasing and they reduce and collapse when the current is decreasing.
When the wire is wound around a core, and the current is switched on or increasing, the field lines circling the conductor expand. When they (rapidly) attain the core, they concentrate in the core due to its much higher "penetrability" (higher permeability). At this moment, the field lines still encircle the conductor wire, but their path is through the core, not just around the wire.
As the expanding circles start outside the core just around the conductor, we see that they have to cross the core walls to enter the core.
A varying magnetic field in a core should not be thought as something permanently contained in the core and flowing along the core with an increasing and decreasing strength. It must be thought as an external field crossing the core walls each time its strength changes, depending on the varying current. This is the reason why we can apply to the transformer, the rule of flux crossing through the core section (near 100%) in order to calculate all what we need.
The ignorance of this phenomenon has led to many reasoning errors ending with the conception of fabulous FE devices but... not working.


Title: Re: Some interesting transformer experiments ...
Post by: SchubertReijiMaigo on January 27, 2011, 07:12:37 AM
So you are saying this experiment is not valid ? Why when he put his magnet bar on the trafo the current droop and the motor accelerate !? Measurement errors with an analogue Ammeter ? I don't undertsand here... ???