# Thread: stepper drive power supply

1. ## stepper drive power supply

Hi ,

I need help with choosing the 24V power supply for my CNC machine.
Iam using 4 stepper drives in my machine.

The stepper motor spec is : bipolar hybrid stepper motor : ( 2Nm, 2.8A, rated voltage : 3.2V )

Iam using 24V power supply to power the motor/drives.

What should be the current rating of my power supply?

Will : 3.2V * 2.8A * 4(motors) == 36 Watts power.

So will a 24V, 2A ( 48 watts ) SMPS power supply be sufficient ?

Or do I need : 3.2V * 2.8A * 4(motors) * 2(phase) == 72 Watts power. ( 24V, 3A )

Or do I need : 24V * 2.8A * 4(motors) == 268 Watts power. ( 24V, 12 A)

What is the current rating I need for my 24V supply to drive 4 stepper motors ( 2Nm, 2.8A, rated voltage : 3.2V )

I read that analog power supplies are better for driving steppers. But I see lot of machines now using SMPS supply also. How big an issue is this analog vs SMPS power supply?

regards

2. What type of drive are you using? That will make a big difference.

3. ## power supply rating for stepper drives .

Hi,

Iam using bi-polar microstepping drives from DPM hongkong.

My question is :

I need help with choosing the 24V power supply for my CNC machine.
Iam using 4 stepper drives in my machine.

The stepper motor spec is : bipolar hybrid stepper motor : ( 2Nm, 2.8A, rated voltage : 3.2V )

Iam using 24V power supply to power the motor/drives.

What should be the current rating of my power supply?

Will : 3.2V * 2.8A * 4(motors) == 36 Watts power.

So will a 24V, 2A ( 48 watts ) SMPS power supply be sufficient ?

Or do I need : 3.2V * 2.8A * 4(motors) * 2(phase) == 72 Watts power. ( 24V, 3A )

Or do I need : 24V * 2.8A * 4(motors) == 268 Watts power. ( 24V, 12 A)

What is the current rating I need for my 24V supply to drive 4 stepper motors ( 2Nm, 2.8A, rated voltage : 3.2V )

regards

4. Originally Posted by CNCpatriot
Or do I need : 24V * 2.8A * 4(motors) == 268 Watts power. ( 24V, 12 A)
This one, I believe

5. Geckodrive's guidelines are

2/3 * 2.8 *4 = 7.46 amps.

I am quite certain you can get away with 4 amps if you want to spend less. You only have 24v so it's very unlikely you will be able to get full power out of the motors. Even with 34v, I cannot get my motors to draw more than 40W even when heavily loaded.