"Robert Baer" wrote in message
link.net...
colin wrote:

seems to be a reasonable solution, just need to have 1 winding with twice
the impedance, and one with half the impedance of the other 2 wich means
1/sqrt(2) turns, shame its not half the number of turns, as I could just
put them 4 parts of the windings in series / parellel. oh and one phase
voltage needs to be slightly higher.

I just played about with the values.

Colin =^.^=
Four phase? Where?
If you have a motor with 5 or 6 wires and have determined that each
winding has a tap (common tap in the 5 wire case), you have a stepper
motor - *not* a "four phase" motor.
BTW, theer is a way of running it with 2 phase 90 degree drive (using a
resistor and a capacitor); the secrets are usually published by the
stepper motor company.

its a 4 phase motor I wound it myself, well im in the procees of doing so
....
it had 16 slots so trying to fit 3 phase windings in seemed awkward so I hit
upon 4 phase,
where each winding is shifted by one slot or 45 electical degrees on the
stator,
making 2 pole pairs.
it makes for a neat winding arangment,
after all I had 4 pwm half bridge channels,
but then I realised 4phase isnt as easy to do as 3phase.

this is not a bi phase stepper motor.

its for small variable (v high) speed reversable drive.

if you look at the plot you see there are 8 power peaks per cycle,
hence 4 true phases.
that is power plot btw not voltage,
maybe thats confusing if you dont notice its power plot,
but that was most useful to compare as the impedances arnt the same.

each winding is in 4 parts (ie 2 pole pairs)
but I since realised they are not all on the same magnetic path so putting
them in series
or parallel is not quite like doing the same with turns on a transformer.

Colin =^.^=