standing wave coil frequency

[gyulasun]

Hello all

I should also add that the inductance of coil A can be changed by shorting a contra-wound coil B. (I have measured this with an induction meter.)

Yes but my understanding in that case is that you waste power by using up some part of the magnetic flux for "heating" the counterwound coil wire.

[Montec]

Hello gyulasun

Yes but my understanding in that case is that you waste power by using up some part of the magnetic flux for "heating" the counterwound coil wire.

True, but speaking in Amp-turns you could change the inductance of a 10 amp 100 turn coil with a 1 amp 1000 turn coil; or change the resonant frequency of a tank circuit with just a switch (or modulate the tank circuit with an electronic switch).

[Montec]

Hello and Happy Holidays to all

"Slow" wave or Phase coupling between two air coils can be accomplished by matching the phase velocity (Vp) of the coils. This will maximize the coupling. Basically you are just matching the ratio of the pitch and coil diameter.
     P1 = Pitch of coil 1 (Distance between adjacent loops in the coil)
     D1= Diameter of coil 1
     P2 = Pitch of coil 2.
     D2 = Diameter of coil 2.
Then
    P1/D1 = P2/D2

Since P1/D1 is (when looking at a right triangle) the tangent (opposite over adjacent) of the acute angle then Vp = CsinÓ¨ = Csin(arctan(P1/Ï€D1))
  where
    Vp = Phase velocity of the signal within the coil
     C = Speed of light
     Ó¨ = Acute angle

When using two wires of different gages (wire diameter) then the gage of the wire can replace the pitch in the above equation if the coil is wound tightly.
     G1 = gage of wire 1
     G2 = gage of wire 2
  then
      D1 = G1((G2+G1)/(G2-G1)) Diameter of coil 1
      D2 = G2((G2+G1)/(G2-G1)) Diameter of coil 2

The diameter of the form used to wind the inside coil is
       D = G1((G2+G1)/(G2-G1) - 1)

A thin layer of tape may be used to separate the inside and outside coils, or they may be contra-wound.

[Tito L. Oracion]

Hi good day 


But This is what Tesla said:
                                               â€œToday's scientists have substituted mathematics for experiments, and they wander off through equation after
                                                equation, and eventually build a structure which has no relation to reality.”


    But still the formula of the vibration is missing. 


        At least your a scientist . joke




But i believe you a little 

[verpies]

Yes but my understanding in that case is that you waste power by using up some part of the magnetic flux for "heating" the counterwound coil wire.

If the counterwound coil is shorted by a capacitor than this capacitor will give back the energy induced in that coil during the next quarter of the cycle.  The resistive RI^2 losses in that coil do not have to be high if the induced current is low and voltage is proportionally high (this is the same voltage that appears across that shorting capacitor).