Tb6600?

[jtar40]

I got another question, I never really thought about it but should I be buying 3 power supplies instead of using just one? The reason I ask is that I just notice in a lot of the pictures on here, the prepared kits people buy online typically come with 3 power supplies, one for each axis. I'm just not sure if there's a greater purpose having the 3 instead of just using one if it still meets the required amperage and voltage ratings for the motor and driver.

The power supply I have is 20 amps, and 24-26 vdc, I'm buying the dm542t motor driver which requires 20-50 vdc. Also I have 3 nema 23's each 3amps. I know I can be using a higher rated power supply (closer to 50 vdc) for optimal torque but if it's not a problem to use only the one, I think I'd stick to my 24-26 vdc power supply.

In short;... is it a problem to run all three axis' on a single power supply if the power supply meets the requirements of the motor driver and motor? And is there a reason kits sell 3 power supplies instead of just the one?

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[Ger21]

No, there's no problem using just one power supply. A single power supply is preferable, imo.

I know I can be using a higher rated power supply (closer to 50 vdc) for optimal torque

Higher voltage gives you more speed, not more torque.
your machine will be twice as fast with 50V as it is with 24V.

You usually see kits with multiple power supplies when the current requirements are higher, as large high current power supplies can be expensive.

[Neale]

If you are using the common switch-mode power supplies (these are generally contained in a single box, lighter weight, and cheaper) then it is very important not to exceed the rated current. If you do, you trip the over-current protection mechanisms, the PSU shuts down temporarily, and things can go wrong. I don't think I've seen kits with multiple PSUs but it's probably to make sure that there is enough current capability. The stepper drivers actually draw current as a series of relatively short pulses; if your three drivers all demand a pulse at the same time then the sun of these might be too much for the PSU. No reason not to use a single supply as long as it can handle the peak current.

A better technical solution is to use a so-called linear power supply. Heavier and a bit more expensive but easy to build yourself from available components (plenty of examples on this forum). The advantage is that they can be rated for the average current draw and can deal with short pulse loads without a problem.

I would disagree with Gerry about voltage and torque. Stepper motors are driven by short pulses. When a pulse begins the current in the motor winding starts to rise, ramping up to its maximum. The higher the supply voltage, the faster the current rises and as it's current that translates into torque, the quicker the torque is developed during the pulse. The overall effect is higher average torque, which helps acceleration. Highest voltage that the driver can stand will give the best overall performance.