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Re: MMC cap bank



Original poster: "Terry Fritz" <teslalist-at-qwest-dot-net>

Hi Jimmy,

Suppose we have 10 amps RMS at 100 BPS and our caps are 0.05 ohm of 
internal resistance (typecal for a 15/60).  From P=I^2R the power lost as 
heat in the caps is 5 watts.  Now lets hook it to a pole transformer and 
run it at 1000 BPS for 100 amps RMS:

P = I^2 x R  == 100^2 x 0.05 = 500 watts.

  The array can run all day at 5 watts.  But 500 watts it will die 
fast!!  Probably like 15 seconds.

Cheers,

         Terry

At 09:07 PM 7/3/2003 -0700, you wrote:

> > Second, keep the BPS rate LOW.  Capacitor current is
> > directionally
> > proportional to BPS.  3000 BPS has 10X the current
> > of 300 BPS and 100X the
> > cap heating!!!
>
>Hi Terry,
>
>I "think" the heating should only be 10x as much. If
>it were 100x then each burst would have to waste 10x
>the power, and I don't see how that is possible. The
>average current will be 10x as much, but the RMS will
>only be SQRT10x as much because the duty cycle is
>greater. Check me on this because it's getting late
>for me ;-)).
>
>=====
>Jimmy