A control device for controlling an electric motor, the device comprising an inverter and a control module implementing a current servo-control loop for the electric motor; an excitation module producing an excitation signal; a synchro-transmitter comprising two coupling windings, an excitation winding constrained to rotate with a rotor of the electric motor, and three measurement windings, the excitation signal being applied to the excitation winding via the two coupling windings; three first synchronous demodulators, each connected to a respective one of the three measurement windings of the synchro-transmitter and to the excitation signal I, and each generating a current setpoint for the current servo-control loop for use by the control module; and three other synchronous demodulators, each connected to a respective one of the three measurement windings of the synchro-transmitter and to the excitation signal Q, and generating a signal providing information about the angular speed of the rotor of the motor for use by the control module.