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Re: MMC resister problem



Original poster: "Jim Lux by way of Terry Fritz <twftesla-at-qwest-dot-net>" <jimlux-at-earthlink-dot-net>

>
> I think the assumption that the voltages are being equalized by virtue of
> the bleeder resistors is invalid.  A 0.15uF cap with a 10 Meg resistor
> across it will have a time constant of 1.5 seconds.  About 180
> charge/discharge cycles will have occurred in this timeframe.  For the
case
> where there are no bleeder resistors, the residual charge problem is most
> evident.  When using reasonable-valued bleeder resistors (or none), the
cap
> voltages will divide based just on the capacitance values.

I wouldn't worry about equalization of voltages (that's more of a value
tolerance vis a vis how close to the max voltage you run the cap issue).
The point of separate bleeders is to make sure that the caps in the middle
of the string also discharge to (close to) zero after a while.  If it takes
30 seconds for one cap, and 25 seconds for the adjacent one, that's not a
big deal.

Also, what's the tolerance on the resistors... 10%?