Abstract: This invention relates to a process for controlling at least one IGBT type transistor enabling its operation under irradiation, in which the value of the threshold value Vge.sub.s of the gate-emitter voltage of a first IGBT transistor (30) under irradiation is measured, and the voltage applied between the gate and the emitter of at least one second IGBT transistor under irradiation is varied during operation, so as to slave the threshold voltage Vge.sub.s of this (these) IGBT transistor(s) to a set value despite the drift caused by irradiation.

Abstract: The invention relates to a control system for direct current actuators in power electronics, based on pulse width modulation, comprising a H-bridge of four switches, each switch incorporating a bipolar transistor (T1,T2,T3,T4) and a diode (D1,D2,D3,D4) connected in reverse parallel between the emitter and collector thereof, and a control circuit (11) for said transistors. The control circuit (11) supplies four signals (V1,V2,V3,V4) permitting the time shifting of the switching of these four transistors (T1,T2,T3,T4) in such a way that during a switching of one of them no pair of transistors is simultaneously switched on, both with respect to transistors belonging to two lateral branches of the bridge and transistors belonging to two opposite branches of said bridge.

Abstract: The invention is a device for controlling and adjusting the tension in the cable of mooring winches or cranes by measuring the torque exerted on a speed reducer having at least one intermediate gear-train, constituted of a pinion and a larger toothed-wheel integrally connected together. The device is characterized in that this intermediate gear-train rotates freely on two bearings supported by a stationary shaft concentric with the intermediate set, which stationary shaft is carried by two fixed supports located outside the bearings. The shaft also carries at least one pair of stress gauges secured between the bearings on two diametrically opposed generatrices of the shaft which are located in the same axial plane as the resultant compression force exerted on both bearings by the two tangential forces applied on the meshing teeth of the pinion and of the wheel of the intermediate gear-train.