Re: [CAD_CAM_EDM_DRO] quick EMC question

Yes Jon I took a look and that seems a good way to do it.
Very nice.

Actually two particular transistors would have to fail in a full bridge to
get a runaway as I think more about it.

I am an audio enthusiast and have about 3000 watts RMS in
the music room. Popped the output on one of the (linear) big amps and
well... there was smoke... and fire.

I just want a real belts and suspenders setup. I even have ace
shock absorbers on the ends of all axes. They are tuned so that 1/2mv^2
=integral force x distance dx.

I don't want to depend on amp overcurrent protection on inhibit circuitry
because it has to be working!

On the lm628/9 you just have to give them your best interpolation
calculation and wait for the first breakpoint interrupt in velocity mode.
Hopefully they will be close.The other axes can then be polled for position
and operated on by changing motion parameters on the fly. Or you can wait
for all
breakpoint reached or trajectory complete interrupts before updating but
this can be choppy. It of course slow to do all that communication but one
can sometimes manage 1ms servo updates. Data can be preloaded and multiple
axes can be fired with a single command (pretty much).

BUT.... the new tech80 site has moved my control boards to
the "legacy product" section. They will have limited support but will not be
made anymore. That is why I stopped writing code
and decided to give EMC my best try. If things don't work I can always go to
a PMD chip or something.

But it's starting to look like you guys are getting the EMC down
to a robust and reliable High performance control system. Hope so. I was off
list a long while building shops and moving dozens of tons of machines. As I
return it seems there is a lot less bandwidth about just getting EMC to work
at all. So that is a good sign for me.

I am just making sure that the computer mb is the right one to use. The
right candidate will be old enough to be known but
new enough to be available still. That goes for the software too. I of
course cannot use one of a kind (not easily replaceable) components.

If it works with a medium old commodity pc I will just go out and buy an
armload of them.


Les


Leslie Watts
L M Watts Furniture
Tiger, Georgia USA
http://www.rabun.net/~leswatts/wattsfurniturewp.html

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