Power Supply Ripple and Noise?

[mtrobregado]

Hi,

I am trying to figure out which is the best 48V 10A power supply for Gecko G201x stepper motor drivers. My choices are below.

The Meanwell NDR-480-48 is cheaper and but has a ripple noise of 150 mV Peak to Peak

The Meanwell SDR-480P-48 is a little bit more expensive but has ripple noise of 120 mV Peak to Peak.

I worry if I choose Meanwell NDR-480-48 it will affect the performance of stepper motors. But is also a cheaper option.

From my 2 choices, which would be a better power supply.

Best Regards,

Markel Robregado

 

[zombieengineer]

From Geckodrive's G201X product page:

The power supply voltage must be between 18 VDC and 80 VDC. The maximum power supply current required is 67% of the motor s rated phase current. An unregulated power supply may be used as long as the voltage stays between the limits; keep the ripple voltage to 10% or less for best results. The drive has a 2 second power-on reset time before the motor is energized.

150mV ripple is about 0.4% which is less than the 10% recommended ripple voltage so either is a valid option.

The Geckodrive stepper motor drivers actually act something like a switch mode power supply (constant current output instead of constant voltage output) - therefore fairly immune to input voltage fluctuations.

NOTE: Geckodrive have a recommended power supply limit based on the stepper motor phase inductance: (Max) Power Supply Voltage = 32 * (?mH inductance)

The above limit is a "rule of thumb" to avoid overheating stepper motors due to excessive core losses (by running them very, very fast). If your phase inductance is > 2.3mH then using a 48V power supply is acceptable.

 

[mtrobregado]

Hi ZombieEngineer,

Thanks. that is a great answer. I am designing a CNC controller using MASSO, and I am sort of new to this. I am more of a microcontroller board engineer. Here is my current connection diagrams.

 

[zombieengineer]

@mtrobregado Looks like a reasonable configuration

With the 2nd power supply (24V for fans) - Have you considered a small "step-down" regulator rather than an additional switch mode power supply?

The following is for a board that can take 60V in and provide 12V/1A & 5V/1A

https://www.ebay.com.au/itm/60V-55V...415523?hash=item4b22bddd63:g:rgQAAOSwgGdZl9Lc

 

[mtrobregado]

Hi ZombieEngineer,

Actually the 24V Power Supply is not only for the fans. It also supplies the MASSO CNC Controller, Homing Sensors, E-Stop, MPG Pendant, and a 4 channel Opto-Isolated Relay. I have separated the wiring diagrams so its understandable for the regular people.

For the fans I have thought of stepping down the 24V to 12v or 5V. Then just use either 12v fans or 5v fans. So, I do not need to do that I just use 24V fans and connect it to 24V 5A power supply.

This design is based from the CNC Controller Project by Peter Oakes.

Regards,

Markel Robregado

 

[testyourdesign]

I have mine running with MEAN WELL SE-600-48 AC to DC Power Supplies. I have three of them to power 7 stepper drives which control the 5 axis motion plus 2 Umbrella controls. I bought them on Amazon for $53 back in May but I see that they are now selling for $77 here in the States. The KL5060D and KL8070D stepper drivers run all axes perfectly on those 48V 12.5 amp power supplies. I find it best to pick a power supply that has a bunch of headroom above the stepper motor at maximum amperage rating.

I have 4 older Gecko G201 on my CNC router running on a single KL-6020 power supply. It's a linear open frame toroidal type power supply that puts out 48V at 20 amps but the load on those affects the actual voltage. I have 4 motors 570oz Nema 23 motors connected to the single KL-6020 power supply and have never had issues with it.

Regards, Stephen Brown

 

[zombieengineer]

@testyourdesign - 570 oz-in stepper motors are quite a beast.

I have been writing a guide (still working on the final tuning write-up) on how to tune stepper motors for maximum performance (speed vs acceleration). From some calculations a 570 oz-in stepper motor should be good for a mill cutting steel (20 ft/min) with a 5 kW spindle motor assuming it uses a lead screw (0.1"/rev lead), double the spindle power for an equivalent ball screw. You won't be loosing steps with that setup.

When tuning the stepper motors on my mill (Sherline mill, ball screw upgrade, 140 oz-in steppers) I run into high speed resonance before I hit the maximum speed of the stepper motor (resonance occurs around 4200 mm/min or 165"/min). The construction of the Sherline mill makes them susceptible to resonance in the lead screws - only supported at one end.

Attached is a copy of the draft of the guide with the final tuning omitted. It has been a challenge to write this at a level that a workshop machinist can understand so apologies if it is too theoretical.