Abstract: A seat plate assembly intended more particularly for the driving seat of a commercial vehicle has a base portion and seat cushioning thereon. Between the base portion and the seat cushioning is a flat operating element with which a switching device can be actuated by way of an operatively interposed elongate actuating member for switching a functional device of the vehicle on or off in dependence on weight on the seat. The operating element is provided at its underside with at least one drive portion with which the elongate actuating member is displaced in its longitudinal direction towards the switch when the seat plate assembly is loaded with a weight, whereby the switch is actuated. Connected to the elongate actuating member is a spring which is mechanically stressed when said displacement movement occurs.

Abstract: A D.C. controlled attenuator which is particularly useful as a D.C. controlled video attenuation circuit providing three tracking channels that can be used as a tracking contrast control in an RGB monitor includes an integrated circuit having at least six MOS field effect transistors on a common substrate, the transistors being of N-channel and P-channel type and being arranged in the three groups of two each connected in complementary symmetry. In each group the gate electrodes of the N-channel and P-channel transistors are connected together, their drain electrodes are connected together and a source of D.C. potential is connected between their source electrodes in parallel. A variable resistor is connected between the gate electrodes of the transistors of a group and the drain electrodes of those transistors providing a feed forward signal path that also preferably includes a variable inductance coil. Input signals are supplied to the gate electrodes of the transistors, and the magnitude of the D.C.