A method for detecting a state of stall in a rotating stepping motor

Abstract

The present disclosure provides a method for detecting a state of stall in a rotating stepping motor, the method comprising the steps of: (i) measuring the back EMF voltage of the stepping motor when the stepping motor is rotating, (ii) calculating a first spread of the back EMF voltage, wherein the first spread of the back EMF is defined by a difference be a highest back EMF value and a lowest back EMF value in a first fluctuation of the back EMF voltage when the stepping motor is rotating. (iii) calculating a second spread of the back EMF voltage, wherein the second spread of the back EMF is defined by a difference be a highest back EMF value and a lowest back EMF value in a second fluctuation of the back EMF voltage when the stepping motor is rotating, (iv) comparing the second spread to the first spread, and (v) determining the stepping motor is stalled when a difference between the second spread and the first spread is higher than a first predetermined value.

Dependencies are inferred from the claim text.