Re: SLA7062 technical stuff

Dave,

Good to know. Problem in my case and I suspect that of many others
who have had similar problems is that we were expressly told by HCNC
that we could use up to 42vdc and the circuit board is even
silkscreened to show that voltage. Further we were told the closer
to 42vdc we got, the better as that would insure maximum power/speed
from the steppers.

Oh well, live and learn...

Tom

--- In CAD_CAM_EDM_DRO@yahoogroups.com, "turbulatordude"
<dave_mucha@...> wrote:

>
> --- In CAD_CAM_EDM_DRO@yahoogroups.com, "jeffalanp" <xylotex@>

wrote:

> >
> >
> > Hi,
> >
> > >--- In CAD_CAM_EDM_DRO@yahoogroups.com, "turyga1963"

<TIntruder@>

> > >wrote:
> > > Being that a great number of postings on the HobbyCNC group

are by

> > > customers who need replacement 7062s, perhaps Dave kicked me

out

> > > because I disrupted a major source of income for him??? I'm
> > > guessing the $3 reduction is costing him a couple hundred a

month.

> > > At least.
> >
> > So it would appear that the SLA7062 is perhaps not as robust

as has

> > been previously suggested. I guess they do go 'pop' as well, if

they

> > are abused, similar to an abused A3977SED.
> >
> > This would most likely be to shorting of phases to one another

or

> > ground, as the disconnect is generally covered by the internal

diodes

> > I mentioned before.
> >
> > Jeff
> >
>
> Mariss has done some of the research. it's been awhile, but IIRC,
> spinning a stepper near max and then decelrating it relativly

quickly

> will/can result in about a 20% over voltage.
>
> That would mean the A3977 with it's 35 volts max would mean 28

volts

> is the best power supply voltage. and the 7062 with it's 44 volts
> would best be powered by a 36 volt supply.
>
> Since Mariss uses a 20% safety factor on his drives, I think it

would

> be a safe bet to use the same rating.
>
> Dave
>
>
>
> Dave
>