DC Servo PS Wattage

[michaelthomas]

Is there a simple rule to figure out the proper sizing of a PS for a DC Servo system like I have seen for stepper systems.

I intend to use the Keling KL34-170-90 servos and Gecko 320x's. The motors have a continuous amperage rating of 7.5. I will be using 3 of them.

I seem to have the option of a 70V 1000w or a 70v 1500w supply from Antek.

Just using the continuous amperage rating and adding them, it would suggest the 1500......Is this overkill?

The PS's seem to have some pretty good headroom, and I'm sure the servos will seldom operate at their continuous rating all at once.

Worst case scenario, I'll just buy the 1500watter.......but if it isn't necessary, I'd like so spend the money elsewhere.

[Bubba]

From what I have read, you add up the continuous amperage and multiply by .667 to get the needed power supply so in you case, 3*7.5*(2/3) would be 15 amp or about 1050 VA at 70V
As you state, you will seldom if ever work all three axis hard at the same time.

[michaelthomas]

OK....that was the formula I had read that i thought was for steppers. Same deal for servos?

[Bubba]

Hope so as that is what I used to design my power supply about 10 years ago for my mill drill!
Been working fine for me all these years.

[michaelthomas]

OK......lol......that would seem to confirm the formula.

[Al_The_Man]

Remember to use the AC voltage for VA calc, (.707xDC).
Al.