3 phae Stepper Motor??

[RajeevCell]

I need to design a drive for testing a 3-phase stepper motor.

I was familiar with 2-phase PM stepper motors, and desgined drives for them (7 years ago). Never worked with these after finishing BSc. I am confortable with full-step/half-step driving of steppers. However, now I see that micro-stepping has become very common in the mean time. Never heard of it in the college.

The motor in question is a Berger Lahr VRDM368. Used in an ink injection pump in our production line. It is a 24V, micro-stepping, 3-phase(!) stepper. I have to admit that, I've never before heard of three-phase stepper motors. The documentation shows simple 3-phase SCIM-like connection of the stator (in delta).

I have a suspiscion that a simple 3-phase, scalar, V/F controlled (without feedback) PWM techniques would do. But like to study more before starting design. Searched Google and this site, but no help about the actual waveshapes.

Can anyone help me? Advice from experience will be a big help. Links to resources will be great, too. Thanks in advance.

Yeasir Rahul

Yeasir Rahul

http://www.voltsmith.com

 

[fsmyth]

These motors were quite common in some full-size 8"
floppy disk drives and a few printers. I have used
them in the past in robotics applications, and still
have a few notes left (including designs cobbled up
for the particular task). They are generally quite
easy to drive using regular TTL logic, and there are
probably still some 3-phase driver chips still
available (haven't checked in a while).
als