Re: 1/2 winding current selection ?

--- In CAD_CAM_EDM_DRO@yahoogroups.com, "John Guenther"
<j.guenther@v...> wrote:

> These are 6 wire Vexta PK-268M-02A motors, 400 step per rev, 2 AMP,

2.25 Ohm

> motors. I have tried running them using the full coil connections

and they

> do not perform well in my setup. I have now hooked them up using

1/2 coil

> mode, center tap and 1 end connection, for each phase and they work

fine.

> My concern is that 2 AMPs may be more than the windings can stand

in this

> mode.
>

I think the termonology is missing here.

a 4 wire motor has 2 coils, one on each phase. there is no way to
use half of one coil.

a 5,6 or 8 wire motor has 4 coils, 2 in each phase.

6 and 8 wire motors can be wired for a single coil, lower inductance
and higher amps, or it can be wired in series, using both coils on
each phase.

the series connection uses 2 coils, has higher inductance and uses
one half the current that a single coil does.

the tradeoff is that a series connection will use half the amps and
run much cooler, but the high speed power will be less.

the single coil connection uses full amps, the motors get much warmer
and the high speed is better.

of course, steppers are not noted for their high speed power anyway.

Hope that helps


Dave