Author Topic: Stubblefield coils (bifilar) and speculations (Read 410853 times)

jeanna · « **Reply #135 on:** April 22, 2008, 09:28:29 PM »

Quote from: resonanceman on April 22, 2008, 08:46:46 PM

Jeanna

I think what the image shows is what is called ring down
can you post the URL for it ?

gary

here is the calculator page. see you in a week.

the whole site is fun,

but please first, tell me again , what do you think?

there is a continuing frequency with 1.7R but to move to 17.7R there is only one peak? Please explain this ring down again.

Is that the thing / combo that we are looking for? I figured not.

Ringing is what I think we are looking for, isn't it?

please explain this , or give it a go anyway?

thanks

jeanna

http://www.coilgun.info/mark2/rlcsim.htm

Pirate88179 · « **Reply #136 on:** April 22, 2008, 09:59:49 PM »

@ Jeanna:

I copied and pasted this from your coilgun site in case you didn't see it. It speaks of ringing. I ran the simulator a few times. Very cool. Thanks for sharing it with us.

"Role of Resistance

The graph's shape is very sensitive to resistance. At rather high resistance it is the main limiting factor on the current in the inductor, and you see the capacitor merely discharges slowly. At medium resistance you will see one lump of coil current which quickly dies out. At very low resistance it will ring (oscillate) as the energy sloshes from capacitor to inductor and back again.

One goal during construction is to minimize the resistance. Don't be too worried about ringing in a coilgun, because the projectile should absorb most of the coil's energy, leaving only a small amount for ringing. If you use an SCR to switch the coil then it will cut off after the first half cycle leaving the excess energy stored in the capacitor again, helping to prepare it for the next firing."

Bill

jeanna · « **Reply #137 on:** April 22, 2008, 10:28:55 PM »

@Bill,
good addition, thanks. Yes, it is a good place to spend an afternoon.

The thing we really cannot do much about is resistance. We can use fat wire and that is all. Using fat wire does nothing for resistance between the 2 different wires, or the wire to bolt resistance or the earth resistance for that matter.

I think this is where I started wanting to know if there could be a way to tweek the magnetism and not have to deal with the resistance, hence I asked myself what role the thickness of the iron wire played in our coils. Also, I used a hollow steel pipe.

BTW that hollow steel pipe produces the best readings. It is the one that gave a steady 18.9 mA inside. That reading went down with the addition of the secondary as they all do, but it is still the best.

Who knows if it is the hollow-ness or the larger diameter that is doing this?

I am not finished with the triplet of coils that looks at the thickness of the wires vs. magnetism question. So, there is more to come.

jeanna

Pirate88179 · « **Reply #138 on:** April 22, 2008, 10:43:36 PM »

@ Jeanna:

I just now tried a trick I used on the electrode set-up in the very beginning. I stuck a very powerful neo magnet on the top of my core and took readings. NO changes of any kind were observed in volts or amps. In the electrode experiment, the volts went up a bit.

This, as you know, is over my head with the concept of ringing/oscillating. Were you suggesting that, assuming this concept does apply to our coils, this wave form peaks at the beginning and would peak again IF it had the chance to get to zero? (or equally below the baseline as it was at the peak) I have been thinking about that. It almost sounds to me like we could use, 1. a capacitor, and 2. possibly a transistor to accomplish this? What do you think? I was thinking along the Bedini line of thought.

Bill

jeanna · « **Reply #139 on:** April 22, 2008, 11:07:00 PM »

Quote from: Pirate88179 on April 22, 2008, 10:43:36 PM

neo magnet on the top of my core and took readings. NO changes of any kind

well I think a steady magnet won't do anything to this cuz i dunno.

Over your head? I guess we are all getting taller fast around here!

Quote

concept of ringing/oscillating.

I need to understand this more. no, I wasn't talking about that because I don't know enough... yet.

Quote

this wave form peaks at the beginning and would peak again IF it had the chance to get to zero?

But on the pic with the higher resistance, it stops oscillating all together. You can see that it was oscillating by looking at the other pic. and gradually the osc changed until it hit that higher resistance and it stopped. At the same time, the amperage goes down which is the bummer.

Quote

1. a capacitor

I have played with caps but I don't really know how to make a circuit with the RLC. I keep going back to those sites so some day I will get it. I think the spark gap thing folks were talking about is the result of the cap, but i dunno.

Quote

2. possibly a transistor to accomplish this? What do you think? I was thinking along the Bedini line of thought

.
I love transistors. I think the earth is going to see a lot of charge in the coming years. Sunspots etc. They could blast a transistor, esp one in the open air so, I want to avoid them only for that reason.

jeanna

resonanceman · « **Reply #140 on:** April 23, 2008, 02:13:47 AM »

Quote from: jeanna on April 22, 2008, 09:28:29 PM

here is the calculator page. see you in a week. the whole site is fun,

but please first, tell me again , what do you think?

there is a continuing frequency with 1.7R but to move to 17.7R there is only one peak? Please explain this ring down again.

Is that the thing / combo that we are looking for? I figured not.

Ringing is what I think we are looking for, isn't it?

please explain this , or give it a go anyway?

thanks

jeanna

http://www.coilgun.info/mark2/rlcsim.htm

Jeanna

I think it is a pretty good example of ring down and how resistance affects resonant ciruuits .

think of the top chart as ringing a large bell

Now ............think of the second chart as ringing the same bell while holding your hand on the bell

thanks for the URL I will look at it later .

I ended up working on my new coil rather than going out earlier today

The readings are not very good .

I can't remember the dry readings .......I took some but didn't write them down ..... I wasn't very impressed .

Wet it is at .369 V DC
The first current reading was .194 mA I will wait a few minutes and see what it goes down to .

gary

resonanceman · « **Reply #141 on:** April 23, 2008, 02:25:21 AM »

Quote from: jeanna on April 22, 2008, 11:07:00 PM

I love transistors. I think the earth is going to see a lot of charge in the coming years. Sunspots etc. They could blast a transistor, esp one in the open air so, I want to avoid them only for that reason.

jeanna

I am trying to avoid transisters too .

gary

resonanceman · « **Reply #142 on:** April 23, 2008, 02:32:13 AM »

Quote from: resonanceman on April 23, 2008, 02:13:47 AM

The first current reading was .194 mA I will wait a few minutes and see what it goes down to .

gary

Isn't the current supposed to drop after the first surge ?

my pancake is at .274 mA after about 20 min ...... it has been wet over an hour

gary

jeanna · « **Reply #143 on:** April 23, 2008, 03:06:42 AM »

Quote from: resonanceman on April 23, 2008, 02:13:47 AM

I think it is a pretty good example of ring down and how resistance affects resonant ciruuits
think of the top chart as ringing a large bell

Now ............think of the second chart as ringing the same bell while holding your hand on the bell

So, does this mean that the magic of the ringing is to find the combo of all the parts that allows a coil to resonate?

At all?

It isn't that there are regular resonances and then there are those that ring?

learned another new thing today.

please confirm for me if this is right. thanks.

jeanna

resonanceman · « **Reply #144 on:** April 23, 2008, 03:26:19 AM »

Quote from: jeanna on April 23, 2008, 03:06:42 AM

So, does this mean that the magic of the ringing is to find the combo of all the parts that allows a coil to resonate?

At all?

It isn't that there are regular resonances and then there are those that ring?

learned another new thing today.

please confirm for me if this is right. thanks.

jeanna

Jeanna

There are different kinds of resonance ...........but resonance is resonance ........it is all about ringing

Another way I have heard resonance described ........it is like electrons " sloshing " back and forth between the cap and the coil . anything that can affect the sloshing will effect the resonance, but in general resistance is usually a big factor

HHHhhhhmmmm I have been watching the current on my pancake for a little over an hour ..........it is .714 mA now .
and still going up

gary

Pirate88179 · « **Reply #145 on:** April 23, 2008, 03:29:30 AM »

@ Gary:

Up is the right direction, I hope it keeps going.

Bill

jeanna · « **Reply #146 on:** April 23, 2008, 03:33:30 AM »

Quote from: resonanceman on April 23, 2008, 03:26:19 AM

HHHhhhhmmmm I have been watching the current on my pancake for a little over an hour ..........it is .714 mA now .
and still going up

gary

Nice.

How are you doing this? just probes on either end?
And it is growing with the help of nothing?

did I miss the whole circuit here? just the pancake?

jeanna

serveradministrator · « **Reply #147 on:** April 23, 2008, 05:45:05 AM »

i guess i posted in the wrong thead for this topic

resonanceman · « **Reply #148 on:** April 23, 2008, 06:51:12 AM »

Quote from: jeanna on April 23, 2008, 03:33:30 AM

Quote from: resonanceman on April 23, 2008, 03:26:19 AM

HHHhhhhmmmm I have been watching the current on my pancake for a little over an hour ..........it is .714 mA now .
and still going up

gary

Nice.

How are you doing this? just probes on either end?
And it is growing with the help of nothing?

did I miss the whole circuit here? just the pancake?

jeanna

Jeanna

I don't have any core at all .......I am just measuring between the copper and iron .
doesn't seem to matter what end .

The only thing I did is get it wet

The reading for the current isn't changing much anymore . It is on 1.124 mA
If I leave it set for voltage it starts around .340 and slowly goes up to around .505 V DC

There doesn't seem to be any AC ..... that is strange because when I was winding it there was more AC than DC

I will try to get a picture online tomorow

gary

Pirate88179 · « **Reply #149 on:** April 24, 2008, 02:52:49 AM »

@ Gary:

More ac than dc? Yes, I would like to know more about this. This was while winding? I wonder what might have changed? I look forward to your pictures.

Bill

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