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Re: MMC Survivability
Original poster: Vardan <vardan01@xxxxxxxxxxxxxxxxxxxxxxx>
Hi,
Although a lower voltage thing, the SISG pushes RMS currents to the
35 Arms region!! At that point, fully metalized MMCs become the
dominate choice. Far higher capacitance but lower peak currents
while still having considerable RMS current... The CD 940C20P47K-F
at 451 amps peak at 13Arms is a choice. One needs to consider the caps at:
http://cde.com/catalogs/940C.pdf
Easily available from rell.com or mouser.com... If you can handle
the "tech", ScanTesla easily resolves the current details:
http://drsstc.com/~scantesla/scantesla800(beta).zip
Cheers,
Terry
At 07:19 PM 8/29/2006, you wrote:
Hi Gerry,
Yes, it might be ok. But it is still riding the edge. Running the
spice model would be ideal for the situation as this will at least
give a model to go by (sure beats trial and error). When it comes to
pigs in common STR mode, Cp is a good thing to spice up if one is
thinking of using MMC's. The voltage capability of an MMC string
becomes important as we near resonance, so the further we are away
the better (in either direction). What is nice about high kva
transformers is STR is still significant energy which helps the MMC
compete with professional pulse caps in that range from a cost
standpoint. However, to get a seriously robust MMC from a voltage
standoff rating, pulse caps are a less expensive upfront cost
(replacement cost is always on the side MMC's). I think for pig
MMC's, we still need a larger value MMC cap to get the cost down.
The 0.15uF's are just too low (I would really like to see a 0.5uF
MMC available). 5kva is still in range of MMC's, so Jim just needs
to decide what he is comfortable with.
Take care,
Bart