NEMA 23 + TB6560 + ATX power supply

Hello everyone.

I was wondering if I could run 3 NEMA 23 stepper motors each rated at 3.6V and 2A. The motors are 6 wires, with 1.8 ohms resistance. I have 2 ATX power supplies. one is 200W and the other is 300W. I am using TB6560 stepper drivers. The 300W power supply has a sticker on it with (i assume) output voltages and amperes, so here they go: +3.3V-28A,+5V-30A,+12V-15A,-12V-0.8A,-5V-0.3A,+5VSB-2A Those are for the 300W one, now for the 200W power supply: +5V-18A,-5V-0.5A,+12V-6.0A,-12V-0.8A,+3.3V-10A,+5SB-1.0A

Now if you could help me, I would want to know if I could power my stepper motors off of these. If you do know, you could provide me with a schematic of all the connections. Thanks for your time. And for your help.

Also if you need any more info, just ask and I'll try to provide it!

Ditch those supplies, you want 24V supply at least (34V is the maximum recommended for the TB6560, so 36V would be pushing it). I presume you want the motors to do more than 150rpm(!)

Stepper drivers are current controllers, stepper motors are current controlled, your motors true ratings are 2A, 1.8ohm, the voltage is not meaningful since back EMF will dominate totally. More supply voltage enables torque to be delivered at higher speeds, but its the current that provides torque.

Perhaps a 24V 4A supply should be enough (stepper drivers pull less current from the supply than they give to the motor, due to the switch-mode conversion). Anyway 5V or 3.3V is utterly useless.

[ if you are not looking for performance (I was assuming a CNC application), then 12V supply might be enough ]

I will try to use a 24 volt. with driver tb 6600. after I'll report. maybe we can share information

To echo some of what MarkT said:

Don't use an ATX power supply, it's 300W total, god knows what it actually produces per channel.

Since you're using a chopper drive (TB6560) you will get the best performance out of the motor and driver using a voltage near the max of what the driver can control.

The 3.6V@1.8 ohm is going to translate to about 2A, if you're using this for holding torque (motor stopped, just holding position) more than this and you're over-driving it for this particular application. Depending on the config of your driver, when the enable function is set, it will be applying this to your motor. If you want the motor to free-spin you must disable the driver.

Generally, the more voltage you have, the faster you can drive the motor, because you can drive more energy into the coils that overcome the back EMF of the last coils. However the maximum speed is largely dictated by the design and configuration of the motor, and generally it will not respond well to being over-driven.

24V is an easy to achieve voltage, and will give good performance across the range of what most Nema 23's are capable of. You can do test and setup with 12V, but the performance, torque, and other things will be much degraded.

Okay, So I need something like a 24V 4-6A switching power supply? I found some that are for LED-s but they look the same as the ones for stepper motors.

If you already have the PC power supplies you could try powering the motors using the 12v outputs. But as @MarkT says, a higher voltage will give better performance.

Be very careful to adjust the current limit on your stepper drivers so that the motors are protected. Even 12v would be enough to let the smoke out.

...R Stepper Motor Basics Simple Stepper Code

I found a 24V 5A power supply, so Ill order it and try it out! thanks for the help

Also do I need a separate 24V 4A Power supply for each stepper motor, or can I use one 24V 4A for all 3 of them?

It should be fine for all 3


ok thanks!

So, I cannot wait for my 24V power supply to arrive, could someone guide me through the process of wiring my current ATX power supplies? It would really help me...