from t3t4

QuoteI don't quite understand why you're not receiving the same results as I am. Even my first demonstration showed well over a volt, and I did it sloppy. So, could you show me what your doing please? I'd really like to see it. I have no doubt whatsoever, that with your current understanding, you can far exceed me. All I ask, is that you look at what you see, don't hit the books every time you have a question. Just take it all for what it is. I will help in every way that I can.

I am not sure if you were addressing me?

I am certainly aiming to get resonance. It is the reason I bought the LC meter... so I can know what the heck the L part is. I am glad too, because with all the centertapped bifilars, I was really having a confusing time.

@gyula,
I also found the same numeric relationship between the inductance of the single parts and the full bifilar winding.
That is,
When measuring one of the filamants alone, I get a figure that is roughly 1/4 the amount of the entire inductance.
So, you get double your money back so to speak when using a center tapped bifilar on a toroid.
Xee2 pointed out that this is because you are dealing with N²turns rather than double.
I am not able to follow the reasoning on that formula yet, so I throw it out to you all for thoughts.

I have been watching prof lewin's reruns again and I have been looking at the 22-25 lectures, which are about LC and RC and RLC circuits. Now he is strapped with the 60 Hz but the interesting thing I caught today is that he shows how to back into resonance when the frequency is given.
In his case it is always about some cosine of something because it is about the wall 60 hz, but the point is that somewhere inside this is a way to find the L or C or both necessary to make the resonance sing from the air or the earth.

There are so many resonances that I wonder if we should pick one?
I see one high one at around 22khz.
The one at 2.4Mhz is a much lower amplitude, so maybe it is not the best to be aiming for.
As I have already said, I have not ever seen a wave at or around 7hz or the so called schuman resonance. So, My vote is against picking that one.
But who knows from what I learned today, if I raise the inductance I am aiming for a resonance that is lower than what I have at the moment.

I am wondering if I should look hard at the stubblefield coils I have made, and make a matched pair of a better LC amount.

I will be roofing my shed tomorrow. This ought to give my brain a break and some fresh air. I will check in in the evening.

I was very tempted to say galvanized when the tin man asked me if I wanted that or painted. I got dark green. BUT I now have a good source for a big galvanized panel I can stick up high if I want to do that in the future! 

jeanna

Quote from: xee2 on September 01, 2009, 07:54:52 PM
@ dllabarre

What seems strangest to me is that the inductor is a short circuit at DC and therefore I would expect it to short out any voltage in the capacitor.

I would agree if the positive was connected also.  Being only the negative is connected it performs differently.

Also, isn't the resistor going to want to use the current and drain the capacitor?  With the inductor replaced with the resistor I don't get any charge in the capacitor.

I now removed the inductor leaving just the capacitor. The capacitor is charging all alone with just one lead of the capacitor connected to the negative side of a 9V battery.


DonL

@Jeanna

I use this resonance calculator.
It's nice because you can supply any 2 of the 3 variables and it calculates the 3rd.  So I usually enter a capacitor value, and a frequency to see if the Henries are within my variable inductor.  If it is then I just hook my variable inductor to my meter and adjust it to the correct value from the calculator.

It's also great for "what if" problem solving.

http://www.whatcircuits.com/lc-resonance-frequency-calculator/

DonL

Thanks DonL,
It makes me laugh (with delight).
I have sooo many coils with unknown flux values and most of them are also toroids...
I am sooo glad I bought that meter.
happy

PLUS I can actually know what the L is for a stubblefield which is an inductor with one copper and one iron wire separated by wet cloth and driven into the earth at about 18 inches high... And that is not even the part you are supposed to use.

I like Barrys coil gun site with sliders so you can move one thing and see what happens to the curve. And they are all air core so there is no fooling with unknown fluxes, but there just is no substitute for actually knowing what the thing in the ground is.

Did you ever work out that odd reading on that toroid of yours?

After the roof is done, I could wind a little toroid like that and see what kind of reading I get, if you have not found out yet. It sure would be an easy way to get lots of Henries if you think they are real.

jeanna

@ dllabarre

Quote from: dllabarre on September 01, 2009, 11:28:06 PM
I now removed the inductor leaving just the capacitor. The capacitor is charging all alone with just one lead of the capacitor connected to the negative side of a 9V battery.

Well that is simple enough. I hooked one end of a 0.47 uF capacitor to the negative terminal of a 9 volt battery. I will check the voltage tomorrow.