Hi I would like to customized a BLDC motor with 2 linear hall sensor. Do I need an extra a pair of pole on rotor to work with MP6546? I supposed that I don’t need that and the motor is driven by MP6546 in sensorless driving.
Hi Holden,
Thanks for reaching out.
For clarification are you saying you have a custom BLDC motor with 2 hall sensors already connected to the motor? Or do you have a custom BLDC motor and would like to use 2 hall sensors that are not already connected?
Hi Kerr,
Not connected yet. However I don’t intend to use an extra magnetic on rotor since it increase dimension.
Hi Holden,
How many phases in your BLDC? How many pole pairs do you have? You may not need to add an additional pair as long as the linear hall sensors are used with a 90-degree phase offset.
By connecting the two linear hall sensors you have to pins HA and HB you should be able to use the linear hall position sensing without issue.
Regarding sensorless operation, it is unclear whether or not this part can support sensorless driving. I will investigate further and get back to you as soon as I find more information.
In the meantime I will add, with any form of sensorless driving, the initial position will be indeterminate. Because of this the motor may move initially in the wrong direction, unless specific algorithms are used to measure rotor position.
If limited in adding in the additional rotor pair, you can use any MPS MagAlpha sensor with SPI/SSC communication.
Hope this helps.
Best,
Stephen
Hi Stephen,
My BLDC is 9N8P.
Due to dimension limitation, that is why I try avoid to put an extra pole on rotor to detect rotor position. The drawing illustrates the motor and hall sensor I tried to put on motor. Would you confirm again it can work with MP6546? Thanks
Hi Holden,
Yes, using the two hall sensors as you outline in the image should work with the MP6546.