The present invention relates to a speed variation transmission device for a motor vehicle powertrain comprising an epicyclic gear train with a sun gear and a crown connected to shaft of thermal engine of said vehicle, as well as a planet gear carrier connected by a motion transmission track to drive axle of this vehicle. The switch includes a control pin to receive a control signal for controlling a current flowing between an input pin and an output pin. The apparatus also includes a low power comparator that has a first and second input and an output. Machines that power down or are removed from proximity of the network infrastructure are eliminated from the ad hoc network. A widened data path is provided to the DRAM array, effectively increasing the data rate of the DRAM array.