Re: Interference-SSTC

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

Original poster: "Jan Florian Wagner by way of Terry Fritz <twftesla-at-qwest-dot-net>" <jwagner-at-cc.hut.fi>


> << When you go down in frequency, remember to add more primary turns so that
>  you don't overpower the mosfets!
>   >>
> Could i try adding a power resistor in series with the primary instead of 
> more turns?

Ok you could. But efficiency will go down a lot. Shorter streamers even at
high power levels.

Say, you half the frequency but still use the same input voltage, and
want the same input power draw. Then the new series resistor to add has a
resistance equal to the impedance of the TC pri-sec system at your new
drive frequency (this could be some ten Ohms or so). 

That it turn means that half the power goes to the streamers, half to the
resistor. T.ex. if your SSTC would draw 400W then you will get 200W into
the TC and 200W into the resistor. 

The 200W into the resistor are "lost" power - heats up. 
I'm sure you want streamers, and not a finnish sauna... :o)

If you go to even less than half the original freq, even more power will
be dissipated in the resistor, and even less in the TC.

Without the resistor and just double the primary turns (to get the _same_
current as in the above scenario with the resistor) all power will be
applied to the secondary coil. So 400W will go as 400W into the TC, and is
not split over resistor and TC.


cheers,

 - Jan

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