2021-07-28 11:38 PM
I use MotorControl Workbench 5.4.5 to control BLDC, but it always send error "over current". I check all setting but not have mistake in MotorControl.
The warning displayed by MotorControl Workbench is due to over current with my settings, but the Max current provided by my power supply is only 6A. And I setting my overcurrent protection 10A.
How can I solve?
I use MotorControl Workbench 5.4.5 to control my BLDC.
Control board: NUCLEO-F746ZG
Motor drive: X-NUCLEO-IHM08M1
Compilation tools: IAR EW for Arm 8.40.1
Other setting details are in this article:https://community.st.com/s/question/0D53W00000xpiEDSAY/xnucleoihm08m1-with-nucleof746zg-can-connect-mcsdk-warning-overshoot-current
Solved! Go to Solution.
2021-08-02 07:10 AM
Hi @KChie.1,
the Vref value is set by resistor divider (R179 and R180) connected to 3.3 V.
Vref = 3.3V x (R180 / (R180+R179) )
If you measure 0.3 V and R180 = 3 kohm, it means that R179 is 33 kohm (the right value).
When you measure the R179 have you remove the resistor from PCB?
Otherwise you may have a misleading measurements due to of parallel paths of 3.3 V supply voltage.
If do not want to remove the R179 you can check the serigraphy on the top that must be "333".
I hope I have clarified your doubts.
2021-07-29 06:32 AM
Hi @KChie.1,
as reported in the X-NUCLEO-IHM08M1 user manual UM1996 the Over Current Protection (OCP) is implemented by hardware with a detection circuit.
By default the comparator threshold (Vref) is 0.3 V.
Had you modify the resistor divider value to obtain 1 V of Vref?
E.g. replace the R180 with a 14 kohm (or a value as close as possible).
Let me know if this info helped you.
2021-08-01 06:40 PM
Hi Cristiana SCARAMEL (ST Employee),
Thanks your reply,
In addition to follow the steps of Motor Profiler, I don't modify the board.
I measured the resistance value of R180 to be 3Kohm and Vref is 0.3V.
And R179 is not 33Kohm, It is 4.65Kohm.
regards
2021-08-02 07:10 AM
Hi @KChie.1,
the Vref value is set by resistor divider (R179 and R180) connected to 3.3 V.
Vref = 3.3V x (R180 / (R180+R179) )
If you measure 0.3 V and R180 = 3 kohm, it means that R179 is 33 kohm (the right value).
When you measure the R179 have you remove the resistor from PCB?
Otherwise you may have a misleading measurements due to of parallel paths of 3.3 V supply voltage.
If do not want to remove the R179 you can check the serigraphy on the top that must be "333".
I hope I have clarified your doubts.