Patent ID: 8777137

Claim:
A method for controlling a grinder unit ( 2 ) having current sensing means for measuring current ( 32 ) used by a grinder motor ( 20 ) and a control device ( 16 ) for controlling the activity of the grinder motor ( 20 ), wherein activity of the grinder motor ( 20 ) is changed on a basis of the measured current ( 32 ) of the grinder motor ( 20 ), the method comprising: a) activating the grinder motor ( 20 ) for a first time period (T 1 ); b) measuring the current ( 32 ) used by the grinder motor 20 during at least a part of the first time period (T 1 , T 9 , T 11 ); c) determining whether the motor current ( 32 ) is below a predefined value (I 1 ) for more than a predefined time period (T 2 ) during the first time period (T 1 , T 9 , T 11 ); d) stopping the grinder motor ( 20 ) for a stopping period (T 3 ) if the motor current ( 32 ) is below a predefined value (I 1 ) for more than a predefined time period (T 2 ); e) continuing to activate the grinder motor ( 20 ) for a time period (T 4 ) if the motor current ( 32 ) is above or equal to the predefined value (I 1 ) for more than the predefined time period (T 2 ) during the first time period (T 1 , T 9 , T 11 ); and f) increasing a duration of the stopping period (T 3 ) if the control device ( 16 ) has stopped the grinder motor ( 20 ) for a predefined number of successive time periods.