Abstract:
A universal power supply system is used for at least one electric consumer. The supply system comprises at least one AC source and a cable connection connecting said AC source to said electric consumer. The AC source has associated therewith an AC/DC converter for converting the AC voltage into DC voltage. The DC voltage generated in this way is adapted to be transmitted to the electric consumer via the cable connection. To improve such a universal power supply in such a way that it is possible to provide a high and stable voltage without any additional components (such as additional heat dissipation components), the AC/DC converter comprises a plurality of AC/DC converter components which, on the input side thereof, are connected in parallel with the AC source and which, on the output side thereof are connected serially to the electric consumer.
Abstract:
An electric actuator for activating a valve device in the oil and natural gas industry, such as a slide valve, butterfly valve, ball valve, blow-out preventer or the like, has at least an actuator housing (3) that can be mounted to the valve device (2) and a displacement device (5) that is held within the actuator housing (3) and driven by means of an electric motor (4). In order, in the case of such an actuator, to register the forces or pressures that arise therein with both a static load or also with dynamic load changes reliably and with the exclusion of corresponding disturbance variables, and in order in this way to increase particularly the operational reliability of corresponding valve devices, at least one force/pressure measurement sensor (6, 7) is arranged between the actuator housing (3) and the displacement device (5). This sensor has, on its two interior facing sides (8, 9), two rings (11, 12) coated with a piezoresistive sensor layer (10) that forms one or more measurement surfaces (19), as well as at least one separating foil ring (13) arranged between these rings. A measurement voltage is applied between the separating foil ring (13) and a ring (11, 12) for determining a force/pressure-dependent resistance level.