am i right ?

Hi everyone.
i have 4 stepper motors nema 17, i am driving them with polulu DRV8825 drivers, to control each motor i'm using a power supply 12v 0.85A, my intention is to control each stepper alone, which means there is one stepper movement at time, so i'm thinking to use my power supply for all my steppers, because if stepper one is moving, the stepper 2,3 and 4 are off, if 2 is moving ,the stepper 1,3 and 4 are off, and so on !
so the power supply will provide voltage and current for the working stepper only, CAN I DO THAT ? POWERING MY 4 DRIVERS FROM THE SAME POWER SUPPLY ?
Thanks in advnced.

You need to post a link to the datasheet for your stepper motors. There are hundreds of different Nema17 motors.

An 850mA power supply seems on the low side.

The normal way stepper motors are used they draw almost the full current even when stationary so that they hold position. In that situation you would need a power supply that can comfortably meet the needs of all the motors together.

If you are keeping motors in the disabled state when they are not actually moving then you cannot be sure that they won’t miss steps.

Stepper Motor Basics
Simple Stepper Code

Thank you Robin2

12V and 0.85A isn't enough for 4 NEMA17 steppers which each take perhaps 5W or so. Steppers
draw full power all the time.

If you want to save power you'll need to find some stepper drivers that support reducing current on
idle (steppers can function well with about 50% current when stationary, as there is more useful
torque at stationary than when moving).

Since power is proportional to current squared for a stepper, 50% current means 25% power - for
your situation this will have a definite effect as you only move one motor at once. However the
cheap convenient step-sticks seem not to support this.

Thanks MarkT !

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