Re: Power supply surge above the Va rating?

--- In CAD_CAM_EDM_DRO@yahoogroups.com, R Rogers <rogersmach@y...>
wrote:

> Yes, it happened one afternoon and not since as far as I know. I

put the 100volt 1000uF caps at each drive to protect them, machine
runs much better. I'm trying to size a transformer for a new control
and curious about surge. Will demand from the motors cause the
transformer to surge above the Va rating? With a proportional DC
voltage drop of course.

> Ron

Current draw for the motors will not cause the power supply voltage
to rise. But rapidly slowing motors down can cause a rise. As Jon
Elson reported you can expect a typical value of 2 volts.


Wally

>
> cnc_4_me <cnc4me@g...> wrote:
>
>
> Was it you who was telling us you were getting voltage spikes so

big

> you heard a cracking sound in your transformer?
>
> Wally
>
>
> --- In CAD_CAM_EDM_DRO@yahoogroups.com, R Rogers
> wrote:
> >
> >
> > A 55 volt secondary, 800 va toroid transformer should yield an

14.5

> amp output. Then when rectified It should be 78 volts DC at 8 amps
> max. Could the current surge above this value under a higher

demand.

> And if so, how much? How would it effect the DC voltage?
> >
> >
> >
> > Ron
> >
> >
> >
> > [Non-text portions of this message have been removed]
>
>
>
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