Abstract: A system for measuring individual cell voltages of a fuel cell stack includes a plurality of voltage scanning units (VSU). Each VSU is arranged for being connected to a group of cells, belonging to the fuel cell stack, the group of cells being provided with terminals that allow measuring a cell voltage. Each VSU comprises a filter/regulator that provides a voltage reference signal Vref, that is applied to a first terminal of a first cell of the group of cells. The VSU further includes a multiplexer arranged for consecutively connecting the other terminals of the group of cells to a first input of an A/D converter, whereby the A/D converter is further provided with a second input for receiving the voltage reference signal Vref. The ADC is further arranged for being fed with a supply voltage Vsup+ and for A/D converting a signal derived from the signals at the first and second input.

Abstract: The present invention is related to a permanent magnet electrical generator/motor comprising a stator, a rotor, a rotational axis and an air gap between stator and rotor so that the magnetic flux across said air gap is essentially oriented along said rotational axis, said rotor preferably comprising a plurality of permanent magnets to form rotor poles, said generator/motor being characterised in that said stator comprises a disc (1), and a plurality of magnetic cores (2), said cores (2) being attached to said disc (1) by attachment means, said cores comprising coils (6) wound round the legs of said cores. Furthermore, said machine comprises means for distributing the flux across the air gap between rotor and stator. Preferably, this takes on the form of flux distribution plates (28,29), placed between rotor and stator.

Abstract: An electrochemical sensor to measure the activity of a metallic component in a molten metal, comprising the molten metal as the measuring electrode, a reference electrode containing the metallic component to be measured, separated from each other by a liquid ion-conducting halide comprising the metallic component to be measured and immobilized in a non-conducting porous support fabricated from a material inert or almost inert to the molten metal, the halide and the reference electrode material, and whereby the reference electrode further comprises an external connection comprising an electric wire held in an electric isolating material which is chemically inert or almost inert to the molten metal and the reference electrode material, characterized in that the sealing of the reference electrode which is adapted to be sealed is done by a high temperature cement and by the molten metal itself and by a gas tight sealing of the external connection above the melt, and the reference electrode is introduced by a melt