Motor doesn't spin, only squeaks (FOC with encoder)

Discussions regarding the Field Oriented Control (FOC) implementation on the VESC.
alexisthethe
Posts: 6
Joined: 14 May 2017, 07:55

Re: Motor doesn't spin, only squeaks (FOC with encoder)

Postby alexisthethe » 15 Sep 2017, 19:20

Hi Christian,

I am stuck with a similar problem. So I would like to know :

Which capacitors and resistors (# of the components on the attached schematics) did you remove to make it work ?
Did you do other hardware changes to make it work ?

removecapares.PNG
removecapares.PNG (17.6 KiB) Viewed 754 times


Thanks.

rew
Posts: 943
Joined: 25 Mar 2016, 12:29
Location: Delft, Netherlands.

Re: Motor doesn't spin, only squeaks (FOC with encoder)

Postby rew » 16 Sep 2017, 10:08

Remove C5, C6, C7.

alexisthethe
Posts: 6
Joined: 14 May 2017, 07:55

Re: Motor doesn't spin, only squeaks (FOC with encoder)

Postby alexisthethe » 17 Sep 2017, 22:35

C5, C6, C7. Thanks rew

And for the resistors ? I guess I should remove R8, R9, R10 and leave the pull-up resistors..

rew
Posts: 943
Joined: 25 Mar 2016, 12:29
Location: Delft, Netherlands.

Re: Motor doesn't spin, only squeaks (FOC with encoder)

Postby rew » 18 Sep 2017, 06:19

No, you CAN remove the resistors, but you don't need to. WITH the capacitors the time-constant is 10k * 4.7nF = 47u sec. That's too long. Without the capacitors, the stray capacitance that remains is about 10pF. Your time constant has dropped to 10k * 10pF = 100ns. Short enough. If you are designing a board, you can choose to leave them out. If you are populating a board with a spot for them, you can opt to mount very low values. But leaving them in has no disadvantages.

Come to think of it.... with the 10k in place, the hall header wil tolerate much higher voltages (spikes) without immediately killing your CPU. I'd leave them in there.


Return to “FOC”

Who is online

Users browsing this forum: No registered users and 1 guest