Re: [CAD_CAM_EDM_DRO] SLA7062 and Re: New Article Posted

jeffalanp wrote:

> 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.
>

I blew up a couple of mine when I first powered up my HCNC board. In my
case I was using a temporary non-isolated power supply and blew up both
the laptop computer and the HCNC board. I was aware that it would
happen and had intended to run the laptop on batteries to avoid the
issue, but then forgot to do so and powered up with the laptop and
controller board both connected to the wall. Toasted a PCB trace killed
the computer (an old 486 laptop) and blew the direction inputs on two of
the 7062's.

After fixing the isolation issue and the the pcb trace I found that all
four axis on the controller board would power up and lock the motors
with the appropriate hissing noise, and that one of them worked fine,
two would step in one direction but not the other, and one wouldn't step
at all. I guessed that the direction inputs on two and at least step on
the other were blown. I bought three new chips, swapped them out and it
all worked as it was supposed to.

Dave K