Re: [CAD_CAM_EDM_DRO] Re: stepper vs. servo

Albee Tang wrote:

>Hi guys,
>
>Talking about Gecko G320 servo driver. Are they fit for any type of DC Servo
>motor? I have a National Servo motor but I could not find the Electrical
>specification.
>
>

Generally, they are designed for use with permanent magnet brush motors.
They could be used with wound-field shunt motors, as well, with a suitable
field power supply. They cannot be used with AC or brushless motors.

>By the way, instead of buying Gecko G320, can we just build one using some
>Power MOSFET construct it in H-Bridge? Wouldn't that be cheaper than buying
>a Gecko driver?
>
>

You also need the PWM modulator, position error counters, encoder interface,
safety circuits, PID compensation, etc. It is not just 4 FETS in a box.
I doubt
you could buy the parts for a Gecko 320 for $114 yourself. (Obviously, the
guy who is ripping them off is doing it by buying in quantity, though.)

I am working on a PWM input servo driver that moves all this stuff back into
the PC, and uses a variant of my Universal Stepper Controller to produce the
PWM waveform. It works REALLY well on the bench, but I want to see it
acutally moving a load before I'm sure it is satisfactory.

Jon