Re: [CAD_CAM_EDM_DRO] cap question

Mike Snodgrass wrote:

> Thanks for bringing the higher voltage factor into light Jon.
> I also have a trans. that will output 35V, which with your calculation,
> would give me 50V, and I would be able to use the same cap. The other way
> would be to use the same trans. And feed it from the "controversial"
> variac, being carefull to put a hard limit on the dial.

Using a variac alone is deadly. Using it with a standard transformer is
quite normal. The hard limit is a good idea to keep from having an
accident.

> My dillema
> is that I have 15 nema 34s,300inoz,3V,4A which I would
> like to use on several machines, which at max 20 times rated V would be 60V.
> But, I also have 4 Nema42s,6A,600oz,5V which I would like to use this driver
> setup with, which may require higher V.

No matter what voltage you use (that a Gecko can handle) the 5 V motors
will have a limited speed, due to inductance. But, they do have a lot
of holding torque. Set up for 70 to 75 V on the power supply, and they
should do pretty well.

> This is also the reason for the
> heavier current output of the trans. You
> are probably right that I would not be running at 25A, but
> I want that headroom.

Note that all of these unregulated power supplies can provide a momentary
surge capacity above the steady-state power requirements. So, you don't
have to provide a power supply that can continuously deliver the worst-case
peak draw of the drivers.

Jon