[Mr.Ed]

Hi guys,

Building my own machine. EdingCNC is up and running. Now mounting and testing electronics. I have three G201's. The steppers are rated 4.7A (I guess per phase that is). I have read the manuals at geckodrive.com extensively.

My questions:
1. The G201 is rated 7A and phase current can be selected up to this 7A with the current setting resistor. How is it that selecting 4.7A is safe for the driver when some moments in time two phases are fired at the same time? Or are they not?
2. Stepper rating would be amperage in RMS, how is that with G201 output? Chopping voltage and current more or less constant?
3. 2. What is the total current used at that time?

Can somebody explain this to me?

W.B.R.

Ed.

[ger21]

1) I can't explain it, but it's a 7 amp drive. You can set it at anything up to 7 amps.
2) I believe that you set it to the peak current, but I'm not positive.
3) The Gecko will never draw more than 2/3 of the current setting, or about 4.66 amps.

[Mr.Ed]

Gerry,

Thanks for the quick reply.

In a nutshell, my thoughts were, that if the G201 takes 80V/7A max, you can't drive two 4,7A phases needing a total of 9,4 amps. I know it works so there must be a better explanation.

Either the phases are not firing at the same time, or the phase current from G201 to stepper motor is not a true RMS value. It can't be because of the chopping principle.

All this resulting in stepper motors not reaching rated power. Or do they?

Anybody?

Thanks,

Ed.