Re: Tank Circuit L/C ratio

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "by way of Terry Fritz <twftesla-at-uswest-dot-net>" <Mddeming-at-aol-dot-com>

Hi Zoran & All, 

>Original poster: "Zoran Tukovic by way of Terry Fritz 
<twftesla-at-uswest-dot-net>" <ztukovic-at-globalnet.hr> 
> 
>Hi All, 
> 
>How can we calculate and about what depending optimal L/C 
ratio in primary tank 
>circuit ? 
> 
>Regards, Zoran 
> 

I believe that optimization is achieving a balance between several constraint 
equations: 
1)     L1C1=L2C2         (resonance) 1=primary, 2=secondary 
2)     R1<2sqrt(L1/C1)       Where R is total resistance of primary circuit 
at res.freq. (ie DC  resistance, AC resistance, eddy currents, skin effect 
etc.) Otherwise circuit does not oscillate. 
3)     0.5*C1Vin^2 = 0.5*C2*Vout^2 ==> Vout (max)= Vin (max)*sqrt(C1/C2) 
4)     For a given resonant frequency, L1*C1=const. Therefore increasing C1 
to store more energy will require decreaseing L1, but this lowers the 
impedance, increases the primary current (gap losses) and decreases the 
coupling by reducing the promary's magnetic field. 
5)     If Co is the capacitance that would resonate with the power supply 
secondary winding, then at 120 bps the voltage on C1 ~V max *Sin(pi/2 
*sqrt(Co/C1)).   

The result of all this is usually to constrain C1 to between 1.5 and 2.5 
times Co. 

I believe this is correct but will welcome other input/enlightenment. 

Matt D.