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: The present invention relates to an arc-quenching device for circuit breakers having double-break contacts for use in low-voltage distribution systems. Provided around a prechamber (41) is a magnetic shield (91) for the purpose of intensifying the magnetic blowing action on an arc formed between the arc guide rails (51, 61) of the prechamber. In addition, a blowing loop (81) is inserted in the arc-quenching circuit and extends in sections parallel to an arc guide rail (61). Prechamber insulation having a bulge constricting the arc area likewise serves the purpose of optimizing the arc run.

Abstract: The current through the components of a half-bridge of an electronic ballast is intended to be limited during the starting phase. For this purpose, the gate of a half-bridge transistor (T2) is driven by a current limiting circuit (D1, D2, D3, T3, C3) in such a way that the current through the transistors (T1, T2) is limited during the starting phase, whereas it remains unlimited during the glow phase and burning phase of the lamp (LA).

Abstract: A device for operating a plurality of discharge lamps is to be fashioned cost-effectively. Consequently, two discharge lamps (71, 72) are operated with the aid of one ballast in whose load circuit the heating current for the individual incandescent filaments (711, 712, 721, 722) is transmitted via a heating transformer with three secondary windings (Lhs1, Lhs2, Lhs3). The associated primary winding (Lhp) is located in a coupling-out circuit (30) with the aid of which the required heating energy is coupled out via an inductor (Lres). The heating current can be controlled by a temperature-sensitive thermistor (PTC).

Abstract: Power factor correction circuit includes an input having a first and second connecting terminal, a first switching element with a control electrode coupled to a current source, a reference electrode coupled to a reference potential and a working electrode, an inductive resistor coupled between the working electrode of the first switching element and the first connecting terminal. The circuit also includes an output having a first and second output terminal, a first diode coupled between the working electrode and the first terminal of the output, a second switching element with a control electrode, a reference electrode coupled to the reference potential and a working electrode, a first capacitor coupled between the control electrode of the second switching element and the working electrode of the first switching element, and a first ohmic resistance coupled between the first connecting terminal of the output and the control electrode of the second switching element.

Abstract: The invention relates to a converter circuit with coupled inductances L1 and L2 which have a core K having an air gap S which is asymmetrical with respect to the inductances.

Abstract: The present invention relates to an arc-quenching device for circuit breakers having double-break contacts for use in low-voltage distribution systems. Provided around a prechamber (41) is a magnetic shield (91) for the purpose of intensifying the magnetic blowing action on an arc formed between the arc guide rails (51, 61) of the prechamber. In addition, a blowing loop (81) is inserted in the arc-quenching circuit and extends in sections parallel to an arc guide rail (61). Prechamber insulation having a bulge constricting the arc area likewise serves the purpose of optimizing the arc run.

Abstract: Power factor correction circuit includes an input having a first and second connecting terminal, a first switching element with a control electrode coupled to a current source, a reference electrode coupled to a reference potential and a working electrode, an inductive resistor coupled between the working electrode of the first switching element and the first connecting terminal. The circuit also includes an output having a first and second output terminal, a first diode coupled between the working electrode and the first terminal of the output, a second switching element with a control electrode, a reference electrode coupled to the reference potential and a working electrode, a first capacitor coupled between the control electrode of the second switching element and the working electrode of the first switching element, and a first ohmic resistance coupled between the first connecting terminal of the output and the control electrode of the second switching element.

Abstract: Circuit arrangement for operating discharge lamps (LP), having the following features: A power factor correction device (PFC) provides an intermediate circuit voltage; an inverter (INV), which draws its power from the intermediate circuit voltage, outputs power to discharge lamps (LP). According to the invention, an oscillation of the power factor correction device (PFC) only takes place when it is started, by means of a starting device (TRG), by an oscillation of the inverter (INV). This provides cost-effective control of the sequences in the circuit arrangement.

Abstract: The current through the components of a half-bridge of an electronic ballast is intended to be limited during the starting phase. For this purpose, the gate of a half-bridge transistor (T2) is driven by a current limiting circuit (D1, D2, D3, T3, C3) in such a way that the current through the transistors (T1, T2) is limited during the starting phase, whereas it remains unlimited during the glow phase and burning phase of the lamp (LA).

Abstract: A device for operating a plurality of discharge lamps is to be fashioned cost-effectively. Consequently, two discharge lamps (71, 72) are operated with the aid of one ballast in whose load circuit the heating current for the individual incandescent filaments (711, 712, 721, 722) is transmitted via a heating transformer with three secondary windings (Lhs1, Lhs2, Lhs3). The associated primary winding (Lhp) is located in a coupling-out circuit (30) with the aid of which the required heating energy is coupled out via an inductor (Lres). The heating current can be controlled by means of a temperature-sensitive thermistor (PTC).

Abstract: Circuit arrangement for operating discharge lamps (LP), having the following features: A power factor correction device (PFC) provides an intermediate circuit voltage; an inverter (INV), which draws its power from the intermediate circuit voltage, outputs power to discharge lamps (LP). According to the invention, an oscillation of the power factor correction device (PFC) only takes place when it is started, by means of a starting device (TRG), by an oscillation of the inverter (INV). This provides cost-effective control of the sequences in the circuit arrangement.

Abstract: The invention provides a device for securing a window sash to the outer frame of the window so that, on the one hand the sash may be locked in a predetermined open position and on the other hand may be pivoted to open it fully. A single push-button serves both to disengage a catch in the predetermined open position and to release the sash for full opening.

Abstract: A pump comprising a housing and two end covers receiving a drive shaft with an eccentric thereon and with a plurality of radial pistons displaceable in radial bores provided in the housing and biased by springs. An inlet passage and an outlet passage are provided in each bore receiving the radial piston. A sealing disc is inserted between the housing and one of the end covers. Sealed through openings for high pressure medium are provided in the sealing disc. The maximal feeding flow of the pressure medium is limited by throttled passages provided in the sealing disc. A pressure control valve is provided, which is connected to an inner chamber of the housing, accommodating the eccentric.

Abstract: A hydraulic gear machine which is particularly suited for use as a reversible hydraulic gear motor includes a pair of gear elements having externally meshing outer peripheral gear portions and stub shafts which are supported in an internal chamber of a housing on respective sleeve-shaped bearings. Two such bearings are arranged at each axial side of the gear elements, one for the stub shaft of each of the gear elements which extends to this axial side. The housing includes a circumferential wall and two end walls. Sealing elements having the configuration of the numeral three are arranged at the interfaces between the bearings and the end walls. The sealing elements are oppositely oriented with respect to a common plane including the axes of rotation of the gear elements at the respective axial sides.

Abstract: An arrangement for centering an end wall of a housing of a hydraulic gear machine, such as a pump or a motor, with respect to the open end of an internal chamber provided in a housing body forming the circumferential wall of the housing includes a plurality of pins which are received in a press-fitting manner in bores of the end wall and protrude beyond an end face of the end wall which faces and closes the open end of the chamber in the mounting position. The pins may have contact surfaces which are turned to the same diameter as the corresponding inner surface of the housing body which bounds the open end of the chamber, or they may exactly fit into the open end, or overlap slightly with the inner surface in which event some material displacement or deformation takes place during the assembly of the end wall with the housing body.

Abstract: A gear machine, such as a gear pump or gear motor, has a housing in a chamber of which there are journalled two gears which mesh with one another. One of the gears is mounted on a drive shaft the end of which is extended outwardly from the housing. The housing is closed at one side thereof with a cover having a stepped bore for receiving the end portion of the drive shaft. The cover is formed with a circumferential projection concentric with the drive shaft and adapted for centering the cover relative to an external element to be coupled with the gear machine. The stepped bore provided in the cover forms a chamber in which a centering ring with a certain radial play is positioned, which centering ring surrounds the drive shaft. A sealing ring is also positioned in the chamber formed in the stepped bore, which sealing ring sealingly closes the housing. The centering ring provides for reliable aligning of the gear machine to the external element adapted to be coupled with the machine.

Abstract: In a permutation lock, a closing bolt is secured within a bore in the lock housing. Setting wheels on the lock housing can be rotated to a position representing the combination of the lock for releasing the closing bolt. Each setting wheel consists of an inner ring and an outer ring which are interconnected for rotational movement as a unit. The setting wheels extend between stops on the housing. One of the stops is displaceable in the axial direction so that the outer rings can be displaced axially relative to the inner rings for changing the combination of the permutation lock.

Abstract: A gear positive displacement machine has a housing, two gear members, and two bearing members supporting the latter. A gap is formed between an inner wall of the housing and a respective one of the bearing member, the gap increasing in two opposite axial directions. It may start from a central transverse plane of the bearing member. The gap may be formed by a convex peripheral surface of the bearing member or by a convex inner wall of the housing.

Abstract: An arrangement for producing a connection between two structural parts for preventing any relative movement thereof, consists of a blind bore in the one part and a through bore in the other part, a pin being inserted in fitting manner into the blind bore and projecting into the through-hole. Since the diameter of the through-hole is larger than the diameter of the blind bore an annular space is obtained within the through-hole which is filled out by a sleeve which is deformable through application of ultrasonic waves.