oh crap, done it again, sorry, mislabelled dso pic
Crutschow.

 

@qtron The general theory of stepper drives, as I have always understood it, is the attempt to maintain the rated motor current through the practical rpm range in order to obtain max rpm from the motor, ...
Max.

Found this too:
pappabravo:
"A stepper motor typically has two resonances, a mechanical one and an electrical one. The mechanical one depends on the moment inertia of the rotor and the load. It typically occurs at around 200 steps per second. The second one is electrical and occurs at around 5000 steps per second. If you ramp the velocity up you can pass through the mechanical resonance without difficulty. You also have to ramp the velocity down. The electrical resonance occurs because the motor runs out of torque at high speed, like all motors do, and there is nothing you can do about that one".
so, like i said, steppers - BAH! -> Brushed servos dont have electrical resonances AFAIK

 

Max.[/QUOTE]
by the way,
found your posting elsewhere,
The max P.S. voltage calculated on the winding inductance.
32 * √L = VMAX
any chance of plugging in some values -or-
tell me the terms of the formula, ie, L in mH, H, or?
where did the 32 come from?
colleague, how can that be fixed, given motor characteristics all vary?

 

As i increase speed the % of PWM in the total pulse falls away to just straight "clean" pulses. Have DSO pics!

Okay.
But that full-on time may be longer than you need for proper motor operation.

 

Okay.
But that full-on time may be longer than you need for proper motor operation.

Had to back off PWM, so that Full on time was MORE!,
Its because I am Full stepping..
Just started new thread w Shortbus, trying to find how to half step, need waveforms,
None on AAC!! AFAIK.
...
Any possible cure re encoder dilemma? not nagging!

 

colleague, how can that be fixed, given motor characteristics all vary?

The main problem I have found is the inductive reactance of the winding's increases with rpm, therefore some method has to be found to ensure the current remains at the motor rated current.
Max.

 

The main problem I have found is the inductive reactance of the winding's increases with rpm, therefore some method has to be found to ensure the current remains at the motor rated current.
Max.

yes, but why is it fixed at 32..
does the rule apply to all motors, configurations like unipolar etc?
What about 5 phase!!?

 

if formula is 32 x /L=Vmax,
and L is mH,
then for mine thats 32x /1.8mH (1.34)
= 43Volts
but for the amazing 162 volts, thats
162/32=/L
5.0625 =/L
=25.628mH !!
Thats not a stepper motor, thats a solenoid!!
of course,
I am assuming terms are mH.. but U havent qualified -- yet!

 

What was the original link you are quoting?
Max.

 

good thing i kept a record:
https://forum.allaboutcircuits.com/threads/stepper-motor-control.110369/page-3
yours is #47, about ⅓ way down
Ha - just found the 'symbol's so heres what i was trying to present:
if formula is 32 x √L=Vmax,
and L is mH,
then for my motor, thats 32x √1.8mH (1.34)
= 43 Volts
but for the amazing 162 volts, thats
162/32=√L
i.e,5.0625 =√L
=25.628mH !!
Thats not a stepper motor, thats a solenoid!!
of course,
I am assuming terms are mH.. but U haven't qualified -- yet!

 

At last, found : http://users.ece.utexas.edu/~valvano/Datasheets/StepperHalfstep.pdf
for all those who r trying to find re 1/2 stepping

 

and yet more, better too: https://www.onsemi.com/pub/Collateral/MC3479-D.PDF

 

Don't know why it was so hard for you to find? A quick Google gives like 83.5 million results. I like this one myself -
https://motion.schneider-electric.com/technology-blog/stepper-motor-basics-half-and-micro-stepping/

 

Don't know why it was so hard for you to find? A quick Google gives like 83.5 million results. I like this one myself -
https://motion.schneider-electric.com/technology-blog/stepper-motor-basics-half-and-micro-stepping/

very nice - yes, like the way its presented,, THANKYOU!!

 

Tried to go to the next page of the blog to continue the story, https://motion.schneider-electric.com/technology-blog/
got this! had this problem heaps of times,
dunno why they allow U to read one page but not the other!
403-FORBIDDEN ERROR
If you are the webmaster of this site please log in to Cpanel and check the Error Logs. You will find the exact reason for this error there.

Common reasons for this error are:

• Incorrect file/directory permissions: Below 644.
• In order files to be read by the webserver, their permissions have to be equal or above 644. You can update file permissions with a FTP client or through cPanel's File Manager.
  Restrictive Apache directives inside .htaccess file.
• There are two Apache directives which can cause this error - 'Deny from' and 'Options -Indexes'.
  

 

ah, eventually found part 2: https://motion.schneider-electric.com/technology-blog/understanding-how-torque-is-produced-ii/
but yeah, still dunno why web behaves like that..

 

Max,
I appear to have dropped off radar, you had asked where the formula came from, I supplied link.
Pls advise,
cheers,

 

Okay.
But that full-on time may be longer than you need for proper motor operation.

Hi , crutschow,
still here hoping for reply re pwm problem for both phases, still need to ensure all four quadrature states provide pwm, especially when encoder is stationary. Pls advise.

Saw your posting of same previous pwm cct on Electro-Tech-Online.com
Are the two forums in parallel operation?, or is Electro-Tech-Online.com the parent forum?.. Pls advise.