I guess we must be looking at or thinking about different things. Perhaps I did not say it well. The DRAW on the power supply is what I'm saying is greatest at zero speed. After all the comment in the earlier post was that the DRAW on the power supply would be greater during acceleration. That statement would be true of a servo motor but is NOT true of a stepper. At least that is my understanding of the meaning of life.
Rayh On Mon, 2008-07-21 at 18:24 +0100, Leslie Newell wrote: > Sorry Ray but you are wrong. You have maximum current at low speed and > stationary but maximum power is at high speed (technically it peaks at > the corner frequency) and maximum acceleration. Like any motor, power > out = power in - losses. Look at fig.14 in the step motor basics and you > will see a step motor power curve. > > So how does the motor consume little power at maximum current? Simple, > the drive reduces the supply voltage to maintain the set current. Power > = voltage * current. > > Les > > Ray Henry wrote: > > Steppers do not consume more electrical power during rapid accel. The > > biggest draw is when sitting still between the time you stop sending > > pulses to the drive and the time it switches to reduced idle current, if > > it has that ability. > > > > Once you size the power supply to the full load demands of the motors > > you have done the job. The gecko paper > > > > http://www.geckodrive.com/photos/Step_motor_basics.pdf > > > > has a good section on power supplies. > > > > HTH > > > > Rayh > > > > > ------------------------------------------------------------------------- > This SF.Net email is sponsored by the Moblin Your Move Developer's challenge > Build the coolest Linux based applications with Moblin SDK & win great prizes > Grand prize is a trip for two to an Open Source event anywhere in the world > http://moblin-contest.org/redirect.php?banner_id=100&url=/ > _______________________________________________ > Emc-users mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/emc-users ------------------------------------------------------------------------- This SF.Net email is sponsored by the Moblin Your Move Developer's challenge Build the coolest Linux based applications with Moblin SDK & win great prizes Grand prize is a trip for two to an Open Source event anywhere in the world http://moblin-contest.org/redirect.php?banner_id=100&url=/ _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
