SLA7062 technical stuff

--- 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