Re: stepper driver help

--- In CAD_CAM_EDM_DRO@yahoogroups.com, "David G. LeVine"
<dlevine@...> wrote:

>
> At 07:28 PM 9/27/2007, you wrote:
> >Note that if the 50V was left on eventually the only thing limiting the
> >current through the motor would be the winding resistance and then it
> >would be like having a 50V supply across a 1 ohm winding (for example)
> >with 50W dissipation. Smell that magic smoke!
>
> John, technical correction:
>
> 50 Volts across 1 Ohm is 50 Amperes or 50V X 50A = 2,500 Watts. Much
> better magic smoke!
>
>
> David G. LeVine
> Nashua, NH 03060

But of course, we all know that the whole premise of a driver is to
monitor the current to the motor and pulse it, right ?

so a 70 volt power supply running the motor would send out pulses up
to the setting for that motor. most of us use something less than 7
amps and most of us use power supplies that are slightly larger than
the sum of the motors current, or in many cases, about 60% of the
total of the motors current.

thats what the current limiting in the design does for us.

Dave

>