Patent ID: 8686678

Claim:
An apparatus for generating a signal for controlling an electric motor ( 110 ), comprising: A) a signal generator ( 126 ) for generating a modulated control signal (PWM_mod) for driving the electric motor ( 110 ), which signal generator ( 126 ) is configured to generate said modulated control signal by modulating a data signal (DIR; ADR; DATA), having data provided for operation of the motor ( 110 ), onto a PWM signal (PWM) having a given pulse duty cycle, the resulting modulated control signal (PWM_mod) maintaining, on average, the same pulse duty cycle as said PWM signal prior to said modulation; and B) a transmitting unit ( 127 ) which, in operation, transfers said modulated control signal (PWM_mod) to the motor ( 110 ), wherein said modulated control signal (PWM_mod), prior to modulation thereof with the data signal, includes successive signal elements ( 710 , 720 , 730 ) that each comprise a pulse off-time ( 712 , 722 , 732 ) having a predetermined off-time duration (T L1 ) and a pulse ( 714 , 724 , 734 ), subsequent thereto, having a predetermined pulse duration (T L2 ), the off-time duration (T L1 ) and pulse duration (T L2 ) being correlated with an electrical power level to be applied to the motor ( 110 ).