A motor control device of the type comprising a stator and a rotor, the stator being provided with at least one winding, the motor being driven by a control module allowing to select, according to a predetermined control law, for terminals (A, B, C) of the at least one winding: • a configuration connected to one of the terminals (V, GND) of a power supply source referenced relative to a fixed reference terminal; and • a configuration disconnected from the terminals (V, GND) of the power supply source, - the control device including at least one transformation module (FPB1, FPB2, FPB3) allowing to transform a source signal (S1, S2, S3) taken off at least at one of the terminals (A, B, C) of the winding into a floating image signal (S_FPB1, S_FPB2, S_FPB3) representative of a counter-electromotive force induced in the winding, the transformation module having: ∘ a time constant determined from characteristics of the motor and / or characteristics of the control module; ∘ at least a first terminal connected to said at least one of the terminals (A, B, C) of the winding, and a second terminal (N, B, C, A), the first and second terminals being likely to have a floating potential relative to the fixed reference terminal, the source signal (S1, S2, S3) being taken off between the first and second terminals, - in this device the frequency of the counter-electromotive force induced in the winding is likely to vary in a determined frequency band; and at least one transformation module (FPB1, FPB2, FPB3) is configured to: ∘ keep the frequency components of the source signal (S1, S2, S3) which are comprised in the determined frequency band; and ∘ cut the frequency components of the source signal (S1, S2, S3) which are not comprised in the determined frequency band. • a configuration connected to one of the terminals (V, GND) of a power supply source referenced relative to a fixed reference terminal; and • a configuration disconnected from the terminals (V, GND) of the power supply source, - the control device including at least one transformation module (FPB1, FPB2, FPB3) allowing to transform a source signal (S1, S2, S3) taken off at least at one of the terminals (A, B, C) of the winding into a floating image signal (S_FPB1, S_FPB2, S_FPB3) representative of a counter-electromotive force induced in the winding, the transformation module having: ∘ a time constant determined from characteristics of the motor and / or characteristics of the control module; ∘ at least a first terminal connected to said at least one of the terminals (A, B, C) of the winding, and a second terminal (N, B, C, A), the first and second terminals being likely to have a floating potential relative to the fixed reference terminal, the source signal (S1, S2, S3) being taken off between the first and second terminals, - in this device the frequency of the counter-electromotive force induced in the winding is likely to vary in a determined frequency band; and at least one transformation module (FPB1, FPB2, FPB3) is configured to: ∘ keep the frequency components of the source signal (S1, S2, S3) which are comprised in the determined frequency band; and ∘ cut the frequency components of the source signal (S1, S2, S3) which are not comprised in the determined frequency band. - the control device including at least one transformation module (FPB1, FPB2, FPB3) allowing to transform a source signal (S1, S2, S3) taken off at least at one of the terminals (A, B, C) of the winding into a floating image signal (S_FPB1, S_FPB2, S_FPB3) representative of a counter-electromotive force induced in the winding, the transformation module having: ∘ a time constant determined from characteristics of the motor and / or characteristics of the control module; ∘ at least a first terminal connected to said at least one of the terminals (A, B, C) of the winding, and a second terminal (N, B, C, A), the first and second terminals being likely to have a floating potential relative to the fixed reference terminal, the source signal (S1, S2, S3) being taken off between the first and second terminals, ∘ a time constant determined from characteristics of the motor and / or characteristics of the control module; ∘ at least a first terminal connected to said at least one of the terminals (A, B, C) of the winding, and a second terminal (N, B, C, A), the first and second terminals being likely to have a floating potential relative to the fixed reference terminal, the source signal (S1, S2, S3) being taken off between the first and second terminals, - in this device the frequency of the counter-electromotive force induced in the winding is likely to vary in a determined frequency band; and at least one transformation module (FPB1, FPB2, FPB3) is configured to: ∘ keep the frequency components of the source signal (S1, S2, S3) which are comprised in the determined frequency band; and ∘ cut the frequency components of the source signal (S1, S2, S3) which are not comprised in the determined frequency band. ∘ keep the frequency components of the source signal (S1, S2, S3) which are comprised in the determined frequency band; and ∘ cut the frequency components of the source signal (S1, S2, S3) which are not comprised in the determined frequency band.