RE: [CAD_CAM_EDM_DRO] to Low ESR or not to Low ESR, that is the ... ( was Re: GECKOS 201

Dave,

The 470 uf cap is not just a "safety valve". It's primary function is to
the internal 100 uf cap from getting too hot due to it's ESR when you
are running the drives at high amperage, a long distance from the power
supply, or with fuses between the power supply and the drive. Mariss
explained this to me when I had a customer which had G201's that were
getting very hot when connected to a NEMA 42 motor. The problem was that
the current drawn at the chopper circuit frequency was high enough that
the ESR of the internal 100 uf cap was causing it to cook. Adding a 470
uf at the drive cured the heating problem.

Tim
[Denver CO]
Sherline Products at Deep Discount
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> -----Original Message-----
> I do understand the ESR, but the 470uF at the input on the Gecko is
> there to filter the ripple from the drives, or rather from the motors
> as they are switched off. The 470uF is there as a safety valve so to
> speak and will not enhance or detract from the performance of the
> Gecko or the power supply.
>
> I just don't see any major benefits from a low ESR vs. a more common
> cap.
>
> Dave