Abstract: A circuit arrangement for operating at least one light source. Cost-effective power factor correction of the system input is achieved by a combination of a charge pump and a valley-fill circuit. According to the invention, the voltage (UN2) produced by the charge pump is fed into the valley-fill circuit with a lag, for example via an inductor (L2).

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 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 electronic ballast for at least one lamp (La) having at least one first switch (S1), the first switch (S1) having at least one working terminal (A1), a reference terminal (B1) and a control input terminal (St1), and at least one auxiliary unit (10), the auxiliary unit (10) having a supply terminal (V1), the supply terminal (V1) of the auxiliary unit (10) being coupled to the working terminal (A1) of the first switch (S1) via a supply unit (12), which comprises at least one inductance (L2).

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: The present invention relates to an electronic ballast for a lamp having a bridge circuit, which comprises at least one first switch (S1) and a second switch (S2) which are coupled between a connection (A1) for a supply voltage and a connection (A2) for a ground potential, a center point (M) of the bridge circuit being defined between the first switch (S1) and the second switch (S2); a first connection (A1) and a second connection (A2) for a lamp (La), the first connection (A1) being coupled to the center point (M) of the bridge circuit via an inductance (L1); and a signal evaluation unit (20), the signal evaluation unit (20) comprising a first input (24) and a second input (22), the first input (24) being coupled to a signal which is at the DC voltage level of the first connection (A1) for the lamp (La), and the second input (22) being coupled to a signal which is at the DC voltage level of the second connection (A2) for the lamp (La), the DC voltage reference potential for the signal evaluation unit (20) be

Abstract: An electronic ballast for a lamp having a bridge circuit, includes at least one first switch and a second switch, a center point of the bridge circuit between the first and second switch, the center point coupled on one side to a reference potential via the series circuit including a first capacitor and a diode and on the other side to a first connection for the lamp via an inductance; a control unit for driving the first and second switches. The control unit has a supply connection coupled to the connection point between the first capacitor and the diode, the voltage across the supply connection being limited in terms of its amplitude, and having a measurement signal input for feeding a measurement signal to the control unit; the measurement signal input being coupled to the connection point between the first capacitor and the diode.

Abstract: The invention is based on an insertable tool with a rotationally driven disk-shaped hub (10, 12), to which a grinding means (14) is secured in the radially outer region. It is proposed that the hub (10, 12) is embodied with a flexural strength that varies in the radial direction.

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: A system with a tool-holding socket, which has a driver device that can be used to operationally connect an insert tool to a drive shaft, and has an insert tool, wherein the insert tool can be operationally connected to the driver device by at least one detent element which is supported so that can move in opposition to a spring element, engages in detent fashion in an operating position of the insert tool, and fixes the insert tool in a positively engaging fashion, wherein at least part of a mechanism for preventing a laterally inverted installation of the insert tool is formed at least onto the tool-holding socket.

Abstract: In a circuit arrangement for operating light sources, inexpensive technologies for power factor correction can be used in combination. A resonant capacitor in a reactance network for coupling the light source is of dual design (C51, C52). A degree of freedom is thus produced which makes it possible to optimize the costs of the circuit arrangement.

Abstract: The invention relates to a self-oscillating inverter circuit, preferably having bipolar transistors in a half-bridge circuit, having a transformer as the feedback means. In contrast to the prior art, the secondary windings of the transformer are not connected in parallel with the base-emitter path but in series with the collector-emitter path. As a result, no saturation transformers are required for feedback.

Abstract: The present invention relates to a circuit arrangement for operating at least one light source. Cost-effective power factor correction of the system input is achieved by a combination of a charge pump and a valley-fill circuit. According to the invention, the voltage (UN2) produced by the charge pump is fed into the valley-fill circuit with a lag, for example by means of an inductor (L2).

Abstract: In a hand-guided electrical tool 3 with a housing 2 that has a receiving collar 20 embodied on it and with a guard hood 1 that can be attached to the receiving collar 20 and has a clamping strap 16, which can move freely around the receiving collar 20 in a first position and rests snugly against the receiving collar 20 in a second position, a secure connection between the guard hood 1 and the housing 2 is achieved by virtue of the fact that the receiving collar 20 has at least one protrusion 21, which protrudes beyond the second area in the radial direction away from the spindle axle 5, and between the protrusion 21 and the housing 2, there is a distance h, which approximately corresponds to the width b of the clamping strap 16, and by virtue of the fact that that the clamping strap 16 has at least one indentation 12 so that the first diameter d1 of the opening 10 of the clamping strap 16 in the vicinity of the indentation 12 is greater than the second diameter d2 in the remaining region, wherein the first di

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 invention is based on an insert tool with a rotationally driveable disk-shaped hub and an abrasive disposed in particular in a radially outer region, in particular of the kind used for a cut-off wheel, a grinding disk, a rough grinding disk, a cutting disk, or an abrasive paper. The invention proposes that the hub (10) have at least one mount (16, 18, 20), which is disposed off-center, extends in the axial direction (14), and is intended for a bolt that constitutes a functional element of a quick-action clamping system.

Abstract: A battery-operated electrical tool (10) is provided with a machine housing (11) that has a longish, substantially rod-shaped housing portion (12) containing an electric drive motor (13) and an end portion (15) on which a terminal connection surface (16) with push-in receptacle (17) for the detachable attachment of a battery packet (14) is provided, which said battery packet is provided with a connection part (18) that comprises a seating surface (19) matched to the connection surface (16) for seating on said connection surface, and comprising a push-in part (20) engaging in the push-in receptacle (17). The end portion (15) is inflected toward one side in relation to the housing portion (12) out of the direction of longitudinal extension. The terminal connection surface (16) of the end portion (15) extends within a plane (21) that is oriented skew in relation to a plane (22) extending substantially perpendicularly to the longitudinal axis (23) of the housing portion (12).

Abstract: In a circuit arrangement for operating light sources, inexpensive technologies for power factor correction can be used in combination. A resonant capacitor in a reactance network for coupling the light source is of dual design (C51, C52). A degree of freedom is thus produced which makes it possible to optimize the costs of the said circuit arrangement.

Abstract: The invention is based on an insertable tool having a rotationally drivable, disk-shaped hub (10, 12), on which a grinding means (14) forming a cutoff disk, grinding disk, roughing disk, or abrasive disk is secured in the radially outer region. It is proposed that the grinding means (14) and the hub (10, 12) are joined via joining means (26) in the manner of a positive connection at least in the direction of rotation.

Abstract: A self-oscillating inverter circuit, preferably having bipolar transistors in a half-bridge circuit, having a transformer as the feedback element. In contrast to the prior art, the secondary windings of the transformer are not connected in parallel with the base-emitter path but in series with the collector-emitter path. As a result, no saturation transformers are required for feedback.