Re: [CAD_CAM_EDM_DRO] Re: Clarifications needed -

Weyland wrote:

>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?
>

Why do you need it so high? What is to be gained by this? Are you having
performance problems with the motors as it is now?

There are autotransformers used to run 230 V air conditioners and similar
equipment in buildings where only 120/208 V is available. They can be
used to either step up or down the voltage by roughly 10%. If you are
getting
82 V now, you should be able to step it down to 74 V or so, which should
be saver for the Gecko drives.

>
>
>
>>>...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?
>

A breakout board can't supply 5 V, unless it is getting it from some other
connector on the computer. Since your box has all in one, just pull it
from a
hard drive connector.

>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.
>
>

OK, the capacitor bank on the power supply should ride through that.
I had a power fail here while machining, and it went completely dark.
I was reaching behind me for a flashlight when the power came back on.
I saw to my amazement that the machine was still chugging away.
The VFD on the 1 Hp spindle motor rode through the outage, supplying
power all the time, the servo amps, axis motor supply and everything
continued without noticing the power dip. I was pretty amazed.
If you use a somewhat oversized PC power supply, it will have longer
ride-through. And, I do have a LOT of capacitors in my servo motor
power supply.

Jon