Re: [CAD_CAM_EDM_DRO] various types of AC/DC drives and their inputs?

Asim Khan wrote:

>Hi!
>
>I have seen a Milling Machine of MAHO, with a damaged control.
>It has Rotary table.
>The x, y and z axis drives are in a single yellow box. the 4th
>drive for rotary table is separate from this box. These drives
>are too from MAHO.
>I am intereseted in replacing its old control with EMC and STG
>but i am not sure about its drives (wether these are AC
>or DC)
>I have experience of EMC with STG and DC servo drives which
>had +/-10 V input signal to control the direction and speed of the
>DC motor. The motors had tacho output which was fed to the dc-drive
>and was handeled only by the dc drive.
>
>I am particularly afraid of AC drives? what kind of Inputs they
>have?
>

They can have any sort of input. Many have the traditional +/- 10 V
velocity command,
but some have other types of signals (CanBus, FieldBus, PWM, proprietary
signals, etc.)

> Can EMC with STG can handle all kind of AC and DC drives?
>

If it has the 10 V velocity command, then it sure can.

>I have heard that some of the AC Drives take some comutation
>signals (what are these?).
>

They tell the drive what currents to run through which windings.

> if yes then are these signals have to be
>generated by STG?
>

Never.

> or are all the required signals to run an AC
>Drives are handeled by the AC servo drive it self?
>
>

The motor should provide whatever signals the drive needs, if they are
from the same
system. You just have to be sure not to cut those wires. The AC motors
usually don't
have a tach, but use the encoder for this purpose. So, the encoder may
need to go to BOTH
the drive and the STG card.

Jon