Re: [CAD_CAM_EDM_DRO] Converter NC problems
Posted by
Charles VanLeeuwen
on 2000-03-10 09:45:21 UTC
It can definitely be a problem. With static and rotary phase converters,
the actual phase leg voltages can be off significantly from nominal. The
control electronics normally draw power from two of the three legs. If they
are pulling from a pair with "off" voltage, it may be off enough to mess up
the control power.
If you use and inverter type converter, the nominal outputs should be pretty
well balanced but they are made up of PWM snips of the DC buss at a few
thousand to maybe 20,000 hertz. Thus you have a lot of high frequency
noise, the emi of which can cause control problems so you may have to do
some control input power line filtering and shielding of any analog signal
lines.
CVL
. I also
the actual phase leg voltages can be off significantly from nominal. The
control electronics normally draw power from two of the three legs. If they
are pulling from a pair with "off" voltage, it may be off enough to mess up
the control power.
If you use and inverter type converter, the nominal outputs should be pretty
well balanced but they are made up of PWM snips of the DC buss at a few
thousand to maybe 20,000 hertz. Thus you have a lot of high frequency
noise, the emi of which can cause control problems so you may have to do
some control input power line filtering and shielding of any analog signal
lines.
CVL
. I also
> seem to recall that there can be problems with some NC machines
> when used with the wrong type of converter. Has something to
> do with deriving single phase power from the 3 phase to drive
> the electronics. Has anyone ever heard any thing about this?
>
> Drew
>