Re: drsstc

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

Original poster: "Jan Wagner" <jwagner-at-cc.hut.fi> 

Hi,

On Wed, 27 Oct 2004, Tesla list wrote:
>Original poster: "Bob (R.A.) Jones" <a1accounting-at-bellsouth-dot-net>
>>Original poster: "Jan Wagner" <jwagner-at-cc.hut.fi>
>> >to cool them!! LOL
>>
>>Well the capacitor doesn't appear to have low ESR exactly ;)
>>They used Z_esr as Z_esr = R_esr = k/C = 1.35E-4 ohm/F / 126E-6F ~= 1.1
>ohm
>
>I think you may have done that wrong it should be
>.35E-4 ohm/F *126E-6F = 44E-10ohm

Oops sorry, I just made a typo with the units. Checking the paper, [k] = 
ohm*Farad and not ohm/F. 1.1 ohm turns still out ok. If it really _is_ ok, 
awfully lossy capacitor and all that ;-)
(http://www.hut.fi/~jwagner/electr/tmp/01296120.pdf, page IV)

>Does it make sense that a 1F cap has series R of 0.000125 ohms
>and a smaller cap of 0.000126F is 1 ohm????

If it's the same "k", then nope! ;)
Not that "k" seems very useful in estimating capacitor ESR's... usually the 
ESR is measured and stated by the capacitor manufacturer, as with different 
capacitance or voltage ratings the cap structure/dimensions also may change 
and thus may make any specified "k" pretty useless for estimating ESR of 
different capacitors...

>Oops I just noticed its your paper.
>Sorry no offense intended.

No offense taken!
I'm not from South Korea, and that's not my paper either :-)) I just got it 
from IEEExplore some time ago and now put it on my website as I thought the 
original poster might find some helpful infos (or at least something where 
to start from), for designing his induction heater or calculating the 
currents and losses in a DRSSTC/OLTC/xTC.

cheers,
  - Jan

-- 
****************************************************
  Helsinki University of Technology
  Dept. of Electrical and Communications Engineering
  http://www.hut.fi/~jwagner/ - jwagner-at-cc.hut.fi