Quote from: EMJunkie on August 11, 2016, 09:11:23 PM


I did see that, yes! I thought I had responded?

Sorry, looks like I may have lost a post somewhere...

Nice Work, it is simple experiments like this, that we can learn the most from!

   Chris Sykes
       hyiq.org

now that you mention it , yes you did, I was having a seniors moment... I will be 81 end of this month, so I can get away with a lot, LOL


Ron

Quote from: i_ron on August 11, 2016, 07:01:34 PM

Sort of confirmation is a test I did with the zero force coil.


Ron

Now test top to bottom with the hall arrow pointing to the right. As in the hall face outward from the coil/magnet.

It is not that all of the N face flux goes all the way to the S face. Some reenters the sides. You can see this with the hall. Once you get the grip with XYZ of the hall orientation you will be able to map out the fields of the coil/mag.

Mags

Quote from: i_ron on August 11, 2016, 09:19:25 PM

now that you mention it , yes you did, I was having a seniors moment... I will be 81 end of this month, so I can get away with a lot, LOL


Ron

Totally understand Ron, no problem! Me too some days!


   Chris Sykes
       hyiq.org

Quote from: Magluvin on August 11, 2016, 09:31:28 PM
Now test top to bottom with the hall arrow pointing to the right. As in the hall face outward from the coil/magnet.

It is not that all of the N face flux goes all the way to the S face. Some reenters the sides. You can see this with the hall. Once you get the grip with XYZ of the hall orientation you will be able to map out the fields of the coil/mag.

Mags

Quite true Mags, there is a definite north and south demarcation when oriented so.


However, as the question pertains to the zero force motor, the right question to ask is what is the orientation of the force that drives the external magnet. In this case the motion would be radially into and out from the coil so is it not safe to stick with the longer looping flux lines?
They seem to be the ones doing the work.


You can see these short lines in the jpg but I think it is the longer loops that we need to watch


Thanks, Ron

@tinman

QuoteLets look at the picture below-->what color line has the highest total magnetic flux flowing through it in one direction ?

Okay I see where your going, however the textbook picture you posted below is inaccurate and the actual total field at the center (blue line) can extend many feet to the side as can the total field past the poles (red line).

QuoteWhat part of the field would cause the greatest induction to occur in a secondary coil?.

The poles I think because while there may be slightly less lines (less flux) the line density is greater (greater field density). In reality a coil will never be induced by all the flux lines at the center red line unless your coil is two feet in diameter which is impractical. On the other hand a small coil covering the whole pole face/end will be induced by nearly all the flux having a very much greater flux density.


You did try covering the whole pole face/end of the core/coil with a secondary coil of identical wire length to your center coil to determine the difference in inductive properties didn't you?. The problem we know all too well is that most of the time our best laid plans are foiled by reality. We see a picture in a textbook or run a simulation and say hey this looks easy. Then we hit the bench and all hell breaks loose and nothing is as it seemed, that's reality and it's a bitch.


Meanwhile I noticed an anomaly in the hall sensor scans I did a year or so ago which EMJ referred to that may prove interesting...back to the bench.


AC