Stubblefield coils (bifilar) and speculations

[jeanna]

That page is a lot of fun. I have trouble tearing myself away from just one more slide.
So, here are 2 pics that will show what I am talking about.

The picture itself shows what the sliders are set to and the name of the file is telling the slider that I changed.

all right no pdf here they are as gif to read here

jeanna

[Pirate88179]

@ Jeanna:

Wow!  that is interesting...I think those curves look a bit familiar almost.  But, what is this telling us?  I do not understand all of the relationships on that program.  What do you think we are seeing here?  Thanks.

Bill

[jeanna]

  What do you think we are seeing here?  Thanks.

Bill

the short answer is I dunno; but I have a couple of ideas.

As you said the curves look familiar.

Here is how I got those 2 curves.

The applet starts at a certain point and I put the voltage to what I see .8vdc is close enough. then I moved the R to 1.7R because that is the resistance in the iron wire. no other reason. a place to start.

Changing the capacitance changes it slowly so I just left it.

Then I changed the L to get an amperage that is in range 86mA. --- but look at the frequency. 8KHz.

I don't know what a meter can see etc, so I move the resistance slider up 10x (a click away) and there is no longer any oscillation. It is just one peak then the line slowly decreases to off the chart small.

So, I think this is what we are seeing.

My plan:

Inside I don't get a Resistance to the bolt. It is infinitly high, I guess. When I go outside I will check my R to the bolt .
[Edit:
I do get voltage to the bolt. and a loud crackling with the sound detector. I keep thinking THIS is the connection that will give us the make and break. Not 5.6 or the 10's - but the wire to the bolt. so it may be where the capacitance is best expressed in this coil.]

Then I will plug that figure into this applet. Then I have only to move the L slider til I get this point of no oscillation.

The next step will be to go to that wire/inductance applet that you found on that radio site, and back into the number of turns and wire size and I think that may give us a starting place!

jeanna

[resonanceman]

I  spent  alot of time  last night   trying to rebuild my  original  coil into   a pancake  .

It turns out that my  idea  of  using  dental floss or  sting  to  sew  the  wires to  the  backing  didn't work out .

Dental floss is not near  strong enough .........and  it  slips  more than I expected ............so  it  turns  out to be a nightmare of  trying to get the  next  stitch  in place   without  the last  few stitches loosing  up  to much ........

HOWEVER .......  I went out  and   got  some  small   ( 4 in )  wire ties .

It is  going to take a bunch of them ........but it is easy  and allows   for  very  accurate  placement of the  wires .

The  ties  work MUCH  better than I  hoped .........and the  coil  will not  be  delicate   ...... It looks like  I could  toss the finished  coil across the room   with no damage .   


I am going to  take a break from  winding  a while .............. got some other things I want to do today .....  ( its nice  outside         )

I  hope  to  have a few readings   from  my new pancake  coil  before I go to bed tonight.


gary

[resonanceman]

Jeanna


I  think what   the  image shows is   what is called  ring down

If you hit a resonant  circuit   with a pulse  it  rings like a bell .

As  you  have  already noticed .....resistance  can dampen  this  ringing  very quickly. 



I  found  a  calculator  for    resonance ......but yours  is  better .   can  you  post the  URL for it ?


gary