Re: Clarifications needed -

Weyland:

If you're more interested in combating voltage fluctuations than
running your mill during a blackout, you might want to look at a
voltage regulator rather than a UPS. They generally keeps the
voltage at about 120, over a pretty broad voltage range (87v-140v
for the one I checked):

http://www.tripplite.com/products/conditioners/index.cfm

15 amp = about 1380 watts or about 1500 volt-amperes

A unit this size will cost significantly less than a UPS and should
adress what you're looking for. I'd call Tripplite on Monday and
speak to an engineer as a sanity check because of the inductive
nature of the load and the motor surges and ask for their guidance.
For sure, your Rong-Fu will cause a surge when you sart it, but I'm
not sure that the AC side of your stepper PS will see much of a
surge when you use the steppers. I think not, but could be wrong.
By the way, APC has similar products, but I've always felt that
Tripplite was a better value, equivalent quality and their tech
support is very good (despite that, my customers buy 50 times as
many APC units as Tripplite units -- no substitute for good
marketing I guess).

Regards,
Jeff

--- In CAD_CAM_EDM_DRO@yahoogroups.com, Weyland <weyland@v...> wrote:
> On Friday 12 September 2003 09:44 pm, washcomp spake:
>
> > I'm going to assume that Mariss Freimanis of Gecko would have
> > labeled them 90 volts instead of 80 volts if it was safe to use
90
> > volts. You're not pushing the envelope, you are probably outside
> > the box and may let the smoke out of your Geckos.
>
> Ah, yesssss... okay.
> Don't wanna let the smoke out.
> They usually don't work after they lose the smoke.
>
> How could I limit the voltage to 79, then?
>
> > > ...do I get that +5V from the computer power supply
> > > or does it come from somewhere in the parallel port?
> >
> > Assuming you are using a parallel port breakout board, it should
be
> > supplying the appropriate five volts. As parallel port output is
> > 5volt TTL level, <snip>
>
> Now I'm confused.
> I thought it was either ground from the parallel
> port, or +5V from the compueter power supply?
>
> > I don't think its a problem (a decent UPS will output a pretty
good
> > sine wave so the PS should see it as AC). Most small UPS's will
> > only run off the inverter when the AC power is cut. Be aware
that
> > if you are trying to give yourself time to shut down during a
> > blackout, keeping the steppers moving, but letting your spindle
stop
> > could create a load and flashy demise for your machine, your
work or
> > anyone standing nearby.
>
> I'm not so much looking for "...30 seconds of run-time..." as much
> as I'm thinking to try and overcome the *NOTORIOUS* and _frequent_
> brown-outs around South Florida.
> The half of a second of free spin on the spindle won't really
> be horrible, but I'd like to not lose steps and such during one.
>
> > The UPS should be sized to carry all the
> > loads for the designed battery life.
>
> Again, just to be clear, I'm not looking to run off of battery
power,
> but rather avoid lost moves during brief but frequent low voltages.
>
> > If your motor is 3 phase, then
> > youl'd need a 3 phase UPS.
>
> 110V Rong Fu. (very old Rong Fu)
>
> > They are available, but if the cost of a
> > parallel breakout board bothers you, your safer letting the PS to
> > the steppers shut off with the spindle than the shock to your
heart
> > of the price of the UPS.
>
> Not that the price of a breakout board bothers me, just that this
project got
> sidetracked for a year already, and I'm looking to use what I've
got, right
> now, as I know it's useable.
>
> I've no aversion to purchasing things I find that I
> may need to upgrade or otherwise improve upon
> afterwards, but want to get things going after such a delay.
>
> Thanks for the input~!
>
> Weyland