Re: [CAD_CAM_EDM_DRO] Stepper Motor Power supply Sizing.

Peter Homann wrote:

>Hi,
>
>I have been looking at Marriss's White paper on Power Supply's where it
>states that the current requirements for a stepper motor is 2/3 of the
>motors rated current in Parallel and 1/3 when in series.
>
>So, If I have a 4ohm, 4A/phase 8 wire stepper and I wire it in parallel, is
>the current requirements for the motor 4*2/3 = 2.66A or is it 2*2.66 =
>5.333A as the motor has 2 phases.
>
>

The 66% comes from the fact that a microstepping drive never puts full
rated current on
BOTH phases at a time. So, don't multiply by 2, and the 2.66A is the
right value. Actually,
you'd only see this current drawn by the driver when accelerating the
motor at near full
load. The current draw at idle and low speed would be much less, due to
the chopping
action of the driver.

Jon