Power supply

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Makingtoothpicks
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Power supply

Post by Makingtoothpicks »

I need to get a new power supply. I am looking at a Means Well SE 450 36v 15A. This will be driving 4 280 oz stepper motors. If there is anyone that knows this stuff and could give me some advice ? The steppers are 8 wire.

Thank you
Don Murphy

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Re: Power supply

Post by usLEDsupply »

i used the Mean Well HRPG-600-48 (13A 624 Watt) on one of my machines with a Gecko drive running 4x 620oz/in motors.
they are a bit more expensive but a great supply with 5yr warranty

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Re: Power supply

Post by Makingtoothpicks »

Thanks for the reply. I will be ordering it.

Don Murphy

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Re: Power supply

Post by martin54 »

What power supply you purchase depends on what motors you have & what drivers you are using. You really need to balance the whole system if you want to get the best performance, if your using 8 wire Chinese motors, 23's or 34's probably then these generally handle 70 volts no problems at all so next look at the drivers you are using, my drivers are rated to 80v so just to be on the safe side my power supply kicks out around 70v. I could run the system on a 36v supply but it would be such a waste.
So basically try & match your power supply to what ever drivers you have if you want the machine to operate at it's best.

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Re: Power supply

Post by PaulRowntree »

I use the Gecko 540, and they have recommendations for the power supplies that are speced by the motor inductance

Vmax = 32 x sqrt( inductance in millihenries )

The html version here (http://www.geckodrive.com/support.html) is good, but the sqrt symbol looks like a V just after Figure 13. The pdf file is clearer.
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Re: Power supply

Post by Makingtoothpicks »

That is a very informative page. Lots of math and theory. Lol I did not understand one word. I have 4 Probiotix 280oz motors rated at 3a each. I could get all the specs on the motors but there really is no more there. They give no volt rating at all. I am using Probotix Uni-polar Stepper Motor Chopper Driver

3 Amp Current Limiting
Buffered Step and Directin Lines
Short Circuit Protection
Full, 1/4, 1/2, 8th & 16th Microstepping Resolution
up to 44V Supply
I am wiring the motors using all 8 wires. I believe it is uni polar series.


280 Oz In. Hybrid
1.8° /200 Steps Per Rev.
3 Amps Current Per Phase (Uni-polar)
8-wire Uni-polar or Bi-polar
NEMA 23 Frame
Factory Enameled Yellow Body
Dual Shaft

Thank you
Don Murphy

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Re: Power supply

Post by Makingtoothpicks »

PaulRowntree wrote:I use the Gecko 540, and they have recommendations for the power supplies that are speced by the motor inductance

Vmax = 32 x sqrt( inductance in millihenries )

The html version here (http://www.geckodrive.com/support.html) is good, but the sqrt symbol looks like a V just after Figure 13. The pdf file is clearer.
I looked at the Probotix site and the inductance is given as 2.2. So 32x2.3=70.4 So I am to believe that these motors are good up to 70 Volts at 2 amps. I think I have it all
wrong. But I think I am good to go with a 350 watt 9.7 36 volt power supply. This is after talking to Probotix. I wish I new something about electrical formulas to work this out
but I do not. I do have I think all the info just don't know how to use it.

Thank You
Don Murphy

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Re: Power supply

Post by PaulRowntree »

No, it is 32 x SquareRoot( 2.2 ) = 47.5 V max, according to the Gecko formulas that I used for my G540. It seems very high compared to the motor ratings because (I think) the drivers do not apply full voltage full time. They monitor the current & voltage, which does not jump up instantly because of the inductance of the windings. So they can play aggressively at first with higher voltages, knowing that the current will take some time to develop, at which point they reduce the power available to the motor.

I think.

Cheers!
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Re: Power supply

Post by martin54 »

Don it's not just down to the motors, you need to take the drivers into consideration as well no point wacking a big power supply in if you are going to blow up the drivers. What is the voltage rating of the drivers?
If it had a 36v supply before & the motor manufacturers have suggested a psu for you to use then maybe best to stick with that if your not sure how to work it all out yourself. If the machine worked fine before the psu failed then stick with what you know.

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Re: Power supply

Post by PaulRowntree »

Absolutely right Martin54!
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Re: Power supply

Post by Makingtoothpicks »

martin54 wrote:Don it's not just down to the motors, you need to take the drivers into consideration as well no point wacking a big power supply in if you are going to blow up the drivers. What is the voltage rating of the drivers?
If it had a 36v supply before & the motor manufacturers have suggested a psu for you to use then maybe best to stick with that if your not sure how to work it all out yourself. If the machine worked fine before the psu failed then stick with what you know.
The voltage of the drivers is in my post 44V. The motors are rated 3A no voltage given. This is not the same setup I had running. These are new motors and new drivers.

Thank You
Don

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Re: Power supply

Post by martin54 »

Sorry Don I missed that bit about the drivers when I read through the post but I would still stick with what I said about buying the PSU they have suggested. If the motors & drivers are from the same manufacturer & they have suggested a PSU for you then at least if you stick with that you have someone to go back to if you have problems.
My motors & drivers are not from the same manufacturer, with the help of people on other forums I matched the motors with suitable drivers & then built an unregulated PSU that was suitable so I knew the whole system was balanced. However I wouldn't have done this if I had not had an understanding of electronics.

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Re: Power supply

Post by m.marino »

I am agree with martin54. My drivers can handle 80V no problem and the motors 32 x sqrt(3.2) = 57.2433V. I built my unregulated power supply to provide 60V approx. Running 4 motors I ended up making sure I had enough current online if needed. The Router in it's current configuration runs in G0 mode at 12.5m/min on the X/C axis (long axis in the UK, Y axis in the US), 8.5m/min on Y axis (only 345mm of travel) and 5.75m/min on Z axis (165mm of travel currently usable). Right now I am looking at upgrading the spindle as that is the limiting factor and I am still getting reasonable feed rates from 4mm and 6mm bits as well as engraving bits, 3.8m/min to 4.8m/min is not really an issue. Though it rarely gets to those speeds due to cutting distances on some projects.

It is a lot of balance and it took a lot of learning for me to have gotten this far. Stick with Martin54's advice on that one and it should not do you any harm. -Michael
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