Hello,
I would like to control a BLDC motor with Hall sensors. The rated current of the motor is 5A, this driver seems to be ok for this:
https://www.fairchildsemi.com/datasheets/FN/FNB40560.pdf
Rather than directly controlling it from a microcontroller (which would take at least 9 pins: 3 for the Hall sensor readouts, and 6 for the H bridges), I would like to use a BLDC controller, which does the commuting logics. Some BLDC controllers have a tachometer output to indicate speed. I would also like to have position feedback from the Hall sensors, i.e. a pulse at every phase change of the Hall sensors, for example. Does anybody have some experience on available devices on the market for this purpose? Or a link to a clear select-by-specs page?
Thank you
Daniel

 

If this is a one off something like a used A-M-C or similar BLDC motor controller with hall effect commutation is one solution.
Hall effect or the equivalent encoder tracks are used now for commutation only, not usually position, this is left to an encoder.
What is the application?
Max.

 

They are a bit expensive, but i've used Maxon 230572 speed controllers you can check out. You control the speed with a voltage input, 0-5V, based on the number of magnet poles of the motor.
So there is no speed feedback other than a red LED indicator on the unit which will light up if you are unable to reach the desired speed you're commanding.

 

If this is a one off something like a used A-M-C or similar BLDC motor controller with hall effect commutation is one solution.
Hall effect or the equivalent encoder tracks are used now for commutation only, not usually position, this is left to an encoder.
What is the application?
Max.

Hello, thanks for the reply. I want to play with servo control - getting familiar, etc. What speaks against using the Hall sensors as encoders (in case I am happy with that resolution)? That would simplify the hardware, I thought.

 

http://www.digikey.com/en/articles/techzone/2013/mar/an-introduction-to-brushless-dc-motor-control

A short primer and ref to various chips from major manufacturers.

 

Hi,
Thanks for the reply. I want to assemble a system where I have - on the long term - full control over the system/software. The part you propose is also too big for me. I have found this:
http://www.ti.com/lit/ds/symlink/ucc3626.pdf
which seems to be compatible with the Fairchild driver I quoted before.
Daniel

They are a bit expensive, but i've used Maxon 230572 speed controllers you can check out. You control the speed with a voltage input, 0-5V, based on the number of magnet poles of the motor.
So there is no speed feedback other than a red LED indicator on the unit which will light up if you are unable to reach the desired speed you're commanding.

 

Hello, thanks for the reply. I want to play with servo control - getting familiar, etc. What speaks against using the Hall sensors as encoders (in case I am happy with that resolution)? That would simplify the hardware, I thought.

The very coarse resolution of using the hall effect sensors usually preclude them for any kind of accurate servo/positioning.
Currently hall effect sensors are rarely used as the have been replaced by commutation tracks included on the positioning encoder.
They offer more accurate switching than the older hall sensor.
Max.