Method for determining a movement of a rotor

A control system for an electric motor, the control system comprising

• a supply module configured to supply a drive signal to a drive coil of the electric motor,
• a sensing module configured to sense a coil current of the drive coil,
• a control module configured to brake the motor by controlling the supply module to gradually reduce the drive signal to zero in a manner that avoids a rotor of the electric motor crossing a ripple generating position after the drive signal has been reduced to zero, wherein the manner of gradually reducing the drive signal to zero includes a first portion at a beginning of braking the motor and a second portion following the first portion, and wherein the first portion has a first characteristic and the second portion has a second characteristic that is different than the first characteristic, wherein gradually reducing the drive signal comprises determining an average value of the coil current and adapting a predetermined current curve for reducing the drive signal to the determined average value.

A control system for an electric motor, the control system comprising

• a supply module configured to supply a drive signal to a drive coil of the electric motor,
• a sensing module configured to sense a coil current of the drive coil,
• a control module configured to brake the motor by controlling the supply module to gradually reduce the drive signal to zero in a manner that avoids a rotor of the electric motor crossing a ripple generating position after the drive signal has been reduced to zero, wherein the manner of gradually reducing the drive signal to zero includes a first portion at a beginning of braking the motor and a second portion following the first portion, and wherein the first portion has a first characteristic and the second portion has a second characteristic that is different than the first characteristic, wherein gradually reducing the drive signal comprises using closed loop current control to regulate the drive signal with the determined coil current as a feedback signal.