Re: Stepper Motor Power supply Sizing.

Hi Jan, Mariss,

re-reading my post, I was thinking more than writing. the poster was
asking if he should use the nameplate or double it as he is using 2
drive circuits. ( a drive circuit would drive a coil. 2 circuits
would drive a pair)

My response was that amp rating for the total use of the motor was
nameplate, and not to double it. In his case, his math should start
with nameplate for the motor, and not double the amps then do the
math.

And, without trying to get overly technical in my post, I said the
current duty cycle in a stepper will drive power to one coil separate
from the other coil. That half of the nameplate amps per coil is
what is being used. My assumption.

In application, it is APPARENT that half of the nameplate is used per
coil. So with the question of selecting a power supply, it is use
nameplate, not double it. With chopper drives the ACTUAL current is
different than the apparent current.

Use 2/3 to determine the low end of the required amp for supply then
round up to what transformer/power supply is available.

Sorry for the unintelligible post, but if you were reading my mind,
you would seen what I was thinking, not what hit the keyboard.

And thanks for speaking up. I wholeheartedly agree that when someone
posts something that is unclear, incorrect or just plain wrong, that
the posts be corrected.

I will wait a day and then go back and delete the post. That way if
anyone wants to see my incomprehensible post, they can, but then it
won't be there in the archives for some future confusion.

Dave

--- In CAD_CAM_EDM_DRO@yahoogroups.com, JanRwl@A... wrote:
> In a message dated 5/29/2003 8:34:53 PM Central Standard Time,
> davemucha@j... writes:
>
> > Are you saying that you for a power supply, you double the
nameplate ?
> >
>
> This was for the OLD way of doing stepper-drives. With modern
CHOPPER-drives,
> you only have to insure the current rating is not exceeded, as the
> "duty-cycle" of the chopping handles the math! LONG story. Late.
Maybe Mariss can
> synopsize what I wish I had time to say about this!
>
>
> [Non-text portions of this message have been removed]