unexspected motor blocking with ST72141

[info51]

Posted on February 04, 2005 at 10:05

unexspected motor blocking with ST72141

[info51]

Posted on May 17, 2011 at 10:18

I try again

Claudio

[gaetano]

Posted on May 17, 2011 at 10:18

Hi Claudio,

please, try to send again the .pdf files because I didn't see them.

Regards,

Tanio

[info51]

Posted on May 17, 2011 at 10:18

Hello Tanio,

I retourn on the same problem again: fews time every thousand starts , i get a wrong situation after the last switched step and before the first autoswitched like the 2 pictures attached, the 1.pdf is correct and the 2.pdf is wrong.

The A trace is high with the start command and low at the first autoswitched step , the B trace is the current on the fase R.

Thanks for your help

Claudio

[stello]

Posted on May 17, 2011 at 10:18

Hello Claudio,

I had a look to the startup pictures and it seems (the resolution is not so high) that the mechanical acceleration set for the ramp-up is not the best. In fact, you can see that in the fifht step the current is not zero but it goes directly from a positive value to a negative one and this does'nt allow the micro to detect the zero crossing of the BEMF. Probably, you should increase the acceleration.

Regards,

Lino