Re: OLTC update - Poor seconadry Q

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

Original poster: "jimmy hynes by way of Terry Fritz <twftesla-at-qwest-dot-net>" <chunkyboy86-at-yahoo-dot-com>


how do you know the q is so bad? did you measure it or calculate it? can you
feel the secondary heating? also weak compared to other 300 watt coils you have
made or seen or are you comparing it to johns formula for input power and park
length? the formula might not be accurate at low powers, i doubt he looked at
alot of 300 watt coils when making the formula. my calculations said the q
should be around 200. i used the javatc to get a guess at the resistance. i
dont trust my calculations too much because i didnt find the equations. i
derived the equation myself, and i make alot of mistakes. 

Tesla list wrote: 
>
> Original poster: "Terry Fritz" 
>
> Hi All,
>
> I have adjusted my coil as best I can but the output still seems "weak". I
> think I now know why. My secondary Q is only 36. That works out to a
> secondary AC resistance of about 3300 ohms!! R = 2 x pi x F x L / Q
>
> Paul - The pinger file is here if your are interested.
>
> http://hot-streamer-dot-com/temp/OLTCsec.CSV
>
> The waveform is at:
>
> http://hot-streamer-dot-com/temp/OLTC08-30-01.gif
>
> Just to give an idea of how bad this is... I am pumping and quenching 317
> watts into the secondary system. 53 watts is going to streamers and a
> stunning 264 watts is going into heating up the secondary!!!
>
> So 83 percent of the power is "lost" :-((
>
> Some notes are at:
>
> http://hot-streamer-dot-com/temp/OLTCnotes.txt
>
> The entries at the last tell of the Q=36 case.
>
> So... I don't k! now if it is the SonoTube, surroundings, proximity effects,
> plastic wrap coating... Have to test some things... A small chance it
> could be the anti-parallel diodes...
>
> Of course, this is not a problem with the basic OLTC technology, that works
> great!, but rather an age old problem of making secondaries without really
> low Q...
>
> Of course, ideas on how I can fix this are more than welcome :-)) 
>
> The specs of the secondary system are:
>
> L = 480mH
> Wire gauge = #28
> Turns = 2760
> Winding length = 41 inches
> Diameter = 10.75 inches
> Q = 36.0 :-p
> Fo = 38.2kHz
> Csec = 35pF
>
> Torroid 24" diameter x 6.5" cord 
> Center or toroid 3.5 inches above last secondary turn.
>
> Cheers,
>
> Terry
>
>



JImmy



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