Measure of hall phase shift

[julienboudens9]

Posted on October 01, 2012 at 13:36

Hello,

In datasheet um1052, chap 5.2.3, there is a method to determine the hall phase shift. I have a delay between the max of emf1 and the rising edge of hall1, but if I have a delay and an angle, I can know the speed, but how to know angle ?

Regards,

[Gigi]

Posted on October 02, 2012 at 08:39

Ciao Julien

In the UM1052 is described a method to measure the HALL phase shift (the distance between max BEMF1 and rising of HALL1) that is required by the firmware to work.This is a value typical of your motor.

You need to compute this delay to know the angle doing a simple proportion. One period of the square wave of each HALL signal is 360°. Let's say that one period is 360ms and the delay is 90ms then you have 90° of angle delay.

Moreover the firmware required the parameter in s16degree that is the conversion of the angle in a interger that fits a 16bit variable. So to compute the 90° you have to do another proportion knowing that maximum value of a 16bit variable is 65536 that means 360°.

The value to be set in the PHASE SHIFT is 65536*(90°/360°) = 16384

Let me know if this is the answer of your question.

Ciao

Gigi