Abstract: The present invention relates to a circuit arrangement for operating at least one electric lamp (LP) having a drive circuit (16), which has at least one terminal for a system voltage (UN) on the input side and at least one terminal for the at least one electric lamp (LP) on the output side; the drive circuit (16) having a control unit (18) and a step-up converter having a step-up converter inductor (L2) and a switch (S1), and the control unit (18) being designed to operate the step-up converter in a discontinuous mode, in which the current (IN) through the step-up converter inductor (L2) has gaps, the duration (?t) of these gaps being varied. It also relates to an operating method for at least one electric lamp (LP) using such a circuit arrangement.

Abstract: A circuit arrangement for operating at least one LED and at least one electric lamp having at least one first filament and one second filament, includes first and second terminals for the corresponding filaments; and a lamp supply unit supplying power to the electric lamp; it also including an LED supply unit coupled to the second terminal for the second filament of the electric lamp and designed to supply power to the at least one LED. Also described is an operating method for the circuit arrangement operating at least one LED and at least one electric lamp as described. The circuit arrangement also includes an LED supply unit, which is coupled to the second terminal for the second filament of the electric lamp and supplies power to the at least one LED.

Abstract: The present invention relates to an electronic ballast for discharge lamps, for example low-pressure discharge lamps, having a converter having a switching element and a two-part lamp inductor which is connected upstream and downstream of the discharge lamp. An electronic ballast according to the invention has a smoothing circuit which reduces voltage jumps caused by switching operations in the converter at the lamp terminals.

Abstract: An electronic ballast for a lamp has a DC voltage connection; a switching unit having a supply voltage with the DC voltage connection being coupled thereto, and a first capacitor coupled between the supply voltage connection and a reference potential; an AC voltage connection, at which a voltage can be made available which has at least one AC component. The series circuit includes a first nonreactive resistor and a first diode, as a second nonreactive resistor coupled between the AC voltage connection and the supply voltage connection, a connection point between the first diode and the second nonreactive resistor, and a second capacitor coupled between the connection point and the reference potential. The first capacitor and the second nonreactive resistor are dimensioned such that the average voltage drop across the second nonreactive resistor is greater than or equal to the average voltage drop across the first capacitor.

Abstract: A circuit arrangement has a drive circuit for a lamp having a first connection for a first filament of the lamp and a second connection for a second filament of the lamp, a protective circuit, coupled on the output side to the drive circuit and on the input side to the first connection for the first filament and the second connection for the second filament such that a first signal correlated with an operational parameter of the first filament, and a second signal, correlated with an operational parameter of the second filament, can be transmitted to the protective circuit. The arrangement also includes a modification apparatus connected between the protective circuit and the first connection and/or the second connection, the apparatus designed to modify the first signal and/or the second signal and to make them available to the protective circuit as a modified first signal and/or a modified second signal.

Abstract: Annular brake disc preform (15), wherein 40 to 80 layers of reinforcement fibers of at least two different lengths (11, 19) ranging from 10-60 mm are distributed in a planar gradient throughout the body of the preform, with the reinforcement fibers located near the exterior planes of the disc being predominately shorter fibers (11) and with the reinforcement fibers located in the central planes of the disc being predominately longer fibers (19).

Abstract: A preform for a carbon-carbon composite part (55) comprising multiple layers of fibrous mats (51, 52, 53) wherein each of the fibrous mats (51, 52, 53) comprises a random carbon-containing fibrous matrix (11) within which is distributed a polymeric binder and wherein adjacent mat layers (51, 52, 53) are bound together by additional polymer binder, stitching and interlocking tabs. The preform of the present invention may be an aircraft landing system brake disc. Also, a method of manufacturing a thick multi-layer composite preform.

Abstract: The present invention makes use of loose fibrous material (for instance, chopped fibers) as reinforcement matrix material in the manufacture of carbon-carbon composites. In accordance with this invention, a constraint fixture is provided which can be separated from the mold. The constraint fixture has an internal shape corresponding to the shape of a desired preform component, with the internal shape being defined by a bottom plate (2), an annular ejector plate (3, 3?), a inner wall (10), an outer wall (4), and an annular top plate (11, 11?). The constraint fixture is normally made of metal, porous ceramic, or carbon material. The constraint fixture of the mold holds the loose matrix materials (fibers, along with any fillers and/or additives). The mold assembly itself is segmented, so that the constraint, fixture and the loose fill materials in the fixture can be removed and subjected to further processing as a unit.

Abstract: The invention relates to an airbag module comprising a gas generator, diffuser and a gas bag. The invention is characterized in that the gas generator (5) is arranged in a diffuser (1) or housing of the gas generator with a stepped structure when seen in a longitudinal section. The diffuser (1) or the housing of the gas generator extends in the lower region of the side wall (2) at a distance from the gas generator (5). The lower region of the side wall (2) extends beyond the gas generator (5) in the direction of the occupant. The diffuser (1) or the housing of the gas generator (5) has a smaller cross-section than the gas generator (5). Openings (6,16) through which the gas from the gas generator flows into the gas bag (10) are arranged in a perpendicular position to the occupant. The upper (4) and lower (2) regions of the side wall are connected to each other by at least one deformable center area (3) of the side wall.