Abstract: The contactless angular displacement and/or torque pickup is characterized in that it comprises two electrically insulating coaxial disks (7a, 7b) that can turn in relation to one another by an angle to be detected and that carry on their opposing faces conductive plane coils (8) in the shape of spirally wound sectors coiled alternately in both directions and whose mutual induction varies as a function of the relative angular position of the detection disks (7a, 7b). Also included is a rotary transformer (6a, 6b) to supply one of the detection disks (7a, 7b), a circuit (18) for supplying the primary (11a) of the rotary transformer and a circuit (17, 18) for processing the signal (S) collected on one of the detection disks (7a, 7b).

Abstract: The device consists of a comparison unit 35 comparing the respective speeds 31a and 32a of the input shaft 2 and the output shaft 7 of the converter with a pre-set value so as to supply a "bridging" control command to an electrohydraulic transducer 14; and a timing unit 34 eliminating the "bridging" by signal 34a during the changeover from one transmission ratio to another in accordance with the data supplied by the unit 20 and transmitting with a delay the changeover control command to the transmission control elements 13a and 13b.It is thus possible to "bridge" or lock out the converter for all the transmission ratios while eliminating the "bridging" when each ratio change is made.