Low Speed Hall Sensor

[nmamore]

Hi,

I have been struggling to run my motor at low speeds and I suspect the Hall Sensors are the limiting factor. In UM1052 I found the following line on page 36. "For speed regulation, there is absolutely no need to have a sampling time lower than the refresh rate of the speed info fed back by the external sensors; this becomes especially true when hall sensors are used while driving the motor at low speeds."

I have a 2 pole pair motor, and I would like to drive it as low as 15RPM using Hall Sensor. Is this feasible? How would I determine the execution rate of the speed regulator?

[msingh]

Hi,

I don't think you will be able to achieve that speed with hall sensors. I suggest you to get an incremental encoder as feedback, I have created a project with incremental encoder 1024CPT and was able to achieve 6RPM using speed control. If you would like to drive the motor even slower then I suggest to create a position control project (you can still use it as speed control, this is determined with the position difference) using AN5464.

Kind Regards

Manpreet Singh