The bifilar pancake coil at its resonant frequency

[AlienGrey]

Ahhh ! One of the best things i ear in that topic   Good shot synchro1 , sometimes someone need to say some trues , to some fellows that simple not show nothing all this years but only open so large their mouth to criticize the nice work of persons like TheOldScientist without even think they not contribute in nothing make that type of considerations . Seems they have special pleasure put dislike in videos and make bad considerations about valid works. Real sad see that type of behavior .

really sad

Hi Nelson well it looks like we are on a learning curve here for through's coil winders who didn't know and the mothers who didn't teach manners and respect off other inner souls into there kids.

[MileHigh]

Ahhh ! One of the best things i ear in that topic   Good shot synchro1 , sometimes someone need to say some trues , to some fellows that simple not show nothing all this years but only open so large their mouth to criticize the nice work of persons like TheOldScientist without even think they not contribute in nothing make that type of considerations . Seems they have special pleasure put dislike in videos and make bad considerations about valid works. Real sad see that type of behavior .

really sad

No Nelson, that was a fair criticism of TheOldScienist.  I take no pleasure in it, but it is a service to people that may not know for themselves.  If you want to buy a car and you know nothing about cars you get your friend that knows about cars to help you make a purchase.  This makes sense, correct?  The same thing applies here.  Like it or not, TheOldScientist's clip is a bad clip.  When you excite a coil with sine waves, the response from the coil should be sine waves.  This is FACT, and clearly there was a MAJOR PROBLEM in TheOldScientist's clip and he did not even mention it.  So you need to understand and acknowledge this.  No person's work is free from critique and I have looked at many of TheOldScientist's clips and I have not been impressed by most of them.

Back to coils.  Why is the inductance of a coil proportional to the square of the number of turns?  I did the experiment a long time ago, and I am not going to do it today.

You can also use your intellect to answer the question and actually understand WHY, and not just accept it as another "rule."  This clip answers the questions HOW and WHY:

https://www.youtube.com/watch?v=Z85J5eW1C1A

[gyulasun]

synchro1,

If you have a bifilar coil and you measured 1.45mH for any one of the windings out of the two and then you measure 5.81mH for the two windings in series connection as you wrote then there is nothing wrong: you are correct with this.

The problem is not this but as follows:
if you make a single wire coil with the same amount of wire you used for the two bifilar windings  i.e. the DC resistance of this single wire coil would be also 5 Ohm (same wire length and same wire OD like the two windings together have in the bifilar) and the mechanical sizes such as the diameter and the length of this coil would be nicely comparable to that of your bifilar coil,
then what L inductance do you think you would measure for this single wire coil?

Because this is the real question here to answer, right?

The answer is you would measure pretty close to the 5.81mH L value. 

I built two such coils, one with a single wire from say 10m long piece of wire, label it as coil A and then I made a bifilar coil from 2 x 5m long wires guided in parallel and connected the two wires in series as you wrote, label this as coil B. I measured very nearly identical L inductances for coil A and coil B. Back then this comparison was done not only by me but Magluvin and TinselKoala: we demonstrated this and you continuously criticised all 3 of us, often with rude words. Three persons separately cannot have crappy L meters. 

Remember what you wrote in your post #33 above:

"Tesla bifilar coils have twice the inductance of single wire coils of the same gauge and copper weight" 

why I quoted this (though the first part of it is not correct) is that it shows you are aware of the condition: the single wire coil should have the same copper weight as the two windings have in the bifilar coil, hence this should mean the length of the wire used for the single wire coil and the added length of the two windings in the bifilar coil should be equal and of the same wire gauge. 

Please demonstrate the measured L inductance of your single wire coil wound with the conditions above.
It is fine you tested your bifilar coil inductance for the individual windings and for their series connection. This latter nicely justifies that if you double the number of turns you get 4 times the inductance, right?

Gyula

[nelsonrochaa]

No Nelson, that was a fair criticism of TheOldScienist.  I take no pleasure in it, but it is a service to people that may not know for themselves.  If you want to buy a car and you know nothing about cars you get your friend that knows about cars to help you make a purchase.  This makes sense, correct?  The same thing applies here.  Like it or not, TheOldScientist's clip is a bad clip.  When you excite a coil with sine waves, the response from the coil should be sine waves.  This is FACT, and clearly there was a MAJOR PROBLEM in TheOldScientist's clip and he did not even mention it.  So you need to understand and acknowledge this.  No person's work is free from critique and I have looked at many of TheOldScientist's clips and I have not been impressed by most of them.

Back to coils.  Why is the inductance of a coil proportional to the square of the number of turns?  I did the experiment a long time ago, and I am not going to do it today.

You can also use your intellect to answer the question and actually understand WHY, and not just accept it as another "rule."  This clip answers the questions HOW and WHY:

https://www.youtube.com/watch?v=Z85J5eW1C1A

MH Solenoids coils and pancake coils have different behavior because their self induction are different , so you simple can not compare in the same perspective when measure a solenoid normal coil or bifilar pancake coil .
About you saying  TheOldScientist's are feeding the coils with a sine wave how you have so sure about that ? Could be a square wave and is for sure . He talk about the resonance frequency coil , and to me is clear that if we feed a pancake bifilar coil  even with a square wave when is in resonance frequency , the output will be a sine wave even ljagged scope traces like you say .
like you told   "Sorry, but I personally have very low confidence in TheOldScientist" i feel exactly the same in relation to you .
What is depreciate is you say He is free energy clickbait when he share some of the best videos explanation that you could find in youtube .
Maybe because comments like yours he close the channel only to a particular subscribers this is clickbait ? I think not .
There you have a jagged scope feed by a square wave .
https://www.youtube.com/watch?v=J1wMalWqa7o

[skycollection 1]

https://www.youtube.com/watch?v=uiLgM3EkQBE
With this bifilar pancake coil i can charge the 12 v battery without magnet rotor, can you describe this experiment...?