Re: [CAD_CAM_EDM_DRO] Re: Les Newell servo current and voltage

turbulatordude wrote:

>Measure the AC input, not the DC.
>
>I'm not sure how the ripple from the drivers would effect the AC, but
>I would tend to think you can get a pretty good idea of the current
>by measuring before the transformer.
>
>

No, due to the switching action, you really don't. I test my servo amps
into
essentially a dead short. I can deliver 20 A to the ammeter shunt and only
draw about 2 A at 36 V from the bench power supply. (This, of course,
reduces the efficiency of the drive to practically zero, as you see.)
So, current in has little relation to current out. Current * voltage IN
(power)
is related to Current * Voltage OUT plus the losses in the drive.

Jon