I am trying to drive a 23-pole pair(i.e. 46 poles) BLDC motor using an LV8139 pre-drive, the output of which is fed to drive the 3 half bridge MOSFETs. I managed to connect the correct phase sequence(out of the 6) between the motor and driver.
The pre-drive IC basically provides a hardware solution for 120 degree and 180-degree commutation(sine wave). It requires a DC control signal to vary the speed of the motor, which I am doing via a potentiometer. Here is the link of the datasheet for the same
Now there is literally zero material on the internet about this chip but I am able to use it to drive the motor. I do have a few problems though:
1.) Mostly I need to give a physical push (by hand) to the motor before it starts to rotate normally. I feel that this is an issue of the hall sequence. But once the external push is given, the motor starts normally.
2.) The specification says that motor will rotate in 120 degree mode till a certain speed and then it will jump to 180 degree sine wave. However I don't see any such transition i.e. the commutation is 120 degree always.
I searched about the first issue on the internet and found some suggestions to add a high value capacitance across the power supply to provide sufficient initial current, but the issue persists. Any suggestions are appreciated. Thanks & Regards