Abstract: An electronic ballast for a lamp having a bridge circuit, includes at least one first switch and a second switch coupled between a connection for a supply voltage and a connection for a ground potential, a center point of the bridge circuit between the first switch and second switches; a first and a second connection for a lamp the first connection coupled to the center point; and a signal evaluation unit. The evaluation unit includes a first input coupled to a signal which is at the DC voltage level of the first connection, and second input coupled to a signal which is at the DC voltage level of the second connection, the DC voltage reference potential for the evaluation unit being designed to be variable within a value range which is greater than or equal to the ground potential and is less than or equal to the supply voltage potential.

Abstract: A ballast (10) for powering at least one gas discharge lamp (20) comprises a switching converter (100) and an inverter (900). Switching converter (100) includes a transistor (130) and a control circuit (200) that provides substantially zero voltage switching of the transistor (130) at a very high frequency. Preferably, control circuit (200) includes a drive circuit (300), a turn-on synchronization circuit (400), a current mirror circuit (500), a rail voltage regulator circuit (600), and a lamp current regulator circuit (700). Drive circuit (300) is preferably realized by a circuit arrangement that includes a standard pulse-width modulation integrated circuit (310).

Abstract: The invention relates to a circuit arrangement for operating lamps. The circuit arrangement essentially comprises a full bridge. According to the invention, at least one inductor is connected in series with a full-bridge branch for switching load relief purposes. The circuit arrangement is preferably suitable for operation using a charge pump. PFC is thus achieved in a single-stage arrangement.

Abstract: In the case of an apparatus for providing a sinusoidally amplitude-modulated operating voltage, two switches are arranged in the form of a half bridge, and an LC element is arranged downstream of the half bridge. The first switch is driven by a first square-wave signal in a clocking with the amplitude modulation frequency per clock cycle, and the second switch (QLOW) is driven by a second square-wave signal, which is shorter than the first signal, with a temporal offset with respect to the first signal in each clock cycle. The LC element (LMOD, CMOD) acts as a filter for the signal resulting from the driving of the switches at a connection point (K) between the switches and allows a DC voltage component and a sinusoidal component of the signal with the fundamental frequency of the clocking to pass through, but substantially filters out harmonics.

Abstract: The invention relates to a low-pressure discharge lamp comprising a glass discharge vessel (1) which is substantially tubular in form and which is closed in a gas-tight manner on the ends thereof, a filling consisting of an inert gas mixture and quicksilver, in addition to an optional luminous coating on the inner wall of the discharge vessel (1). Two current supply inlets are respectively melted into the two ends of the discharge vessel (1), with a helical electrode secured thereto (5). The invention is characterized in that in order to increase the switching resistance of the lamp in a cold start operation, at least one other electrode (7,8) made of a conductive material is arranged in the region between the helical electrode (5) and the connecting end of the discharge vessel (1) and one end of said other electrode (7, 8) is electrically connected to one of the two current supply inlets (3,4).

Abstract: A starting apparatus for a high-pressure discharge lamp provided with an auxiliary starting electrode, has a series resonant circuit for the purpose of generating the starting voltage for the high-pressure discharge lamp. The resonant inductance of the series resonant circuit includes the primary winding of a transformer, whose secondary winding is provided for the purpose of applying the starting voltage to the auxiliary starting electrode (Z) of the high-pressure discharge lamp. The invention also relates to a high-pressure discharge lamp, in particular to a vehicle headlight lamp, having such a starting apparatus arranged in the lamp base.

Abstract: A lamp contains a voltage conversion circuit that converts a line voltage to an RMS load voltage and includes a switch and a microcontroller that operates the switch to define the RMS load voltage. The microcontroller senses a load voltage of the lamp, compares the sensed load voltage to a reference RMS voltage, and operates the switch in response to the comparison so that the RMS load voltage is substantially constant at the reference RMS voltage over an operating range of the line voltage and so that the RMS load voltage decreases with decreasing line voltage at line voltages less than the operating range. The operating range of the line voltage is defined to have a minimum that is a non-zero line voltage at which a load current is a predetermined maximum. The voltage conversion circuit may be a phase clipping circuit or a pulse width modulation circuit.

Abstract: A lighting system (10) has: a fixture (12) with an axis of orientation (14); and a light source (16) mounted within the fixture (12). A ballast (20), usually positioned on the side of the fixture away from the light source, is associated with the light source (16), the ballast (20) having a first end (22) attached to the light source (16) via appropriate wires and a second end (24) attached to an electrical power source (26), also by appropriate wires. The connector (28) is composed of inline electrical connector halves (30, 32) having proximal mating ends (34, 36), an axis of attachment (38) and distal ends (40, 42) provided with strain relief mounting means (44). One of the electrical connector halves, for example, (30), has a locking tongue (46) extending along the axis of attachment (38) and the other half, (32) in this instance, has a locking tongue receptor (48) for receiving the locking tongue (46), the tongue and receptor functioning to maintain the connector halves in a joined and locked position.

Abstract: A subassembly (10) for a lamp base, the subassembly (10) has an outer (12) housing having a circumferential wall (14) and a top (16) closing one end (18) of the outer housing (12); at least one lamp receiving aperture (20) in the top (16); and an inner housing (22) contiguous with an entire inside surface (24) of the outer housing (12), the outer housing (12) being a metallic material and the inner housing (22) comprising a plastic material.

Abstract: A phase-control power controller converts a line voltage to an RMS load voltage and includes a phase-control clipping circuit that clips a load voltage to provide the RMS load voltage. The power controller may be in a base of a lamp and connected to a lamp terminal. The phase-clipping circuit establishes a phase conduction angle that determines the RMS load voltage for the lamp and includes a transistor switch and a microcontroller that operates the transistor switch, where ON/OFF periods of the transistor switch define the phase conduction angle. The microcontroller senses a load voltage at the lamp terminal, compares the sensed load voltage to a reference RMS voltage, and adjusts the ON/OFF periods of the transistor switch in response to the comparison to cause the load voltage to approach the reference RMS voltage. The circuit may be used for reverse, forward, or forward/reverse hybrid phase clipping.

Abstract: The invention relates to a novel ballast for a discharge lamp, in which a continuous-operation control circuit is brought out of operation when a physical operation, which defines a preheating time, of a preheating timer has as yet not been sufficiently returned if the lamp is intended to be restarted.

Abstract: The invention relates to a circuit arrangement for detecting a crest factor of a lamp current or a lamp operating voltage of an electric lamp (2), the circuit arrangement having a first subcircuit (15), which is designed to determine an averaged value from an input signal applied to the circuit arrangement, having a second subcircuit (16), which is designed to determine a maximum permissible value from the input signal applied to the circuit arrangement and having a comparator circuit (17), which is designed to produce a comparison signal from the output signal of the first subcircuit (15) characterizing the averaged value and from an output signal of the second subcircuit (16) characterizing the maximum permissible crest factor. The invention also relates to a method for detecting such a crest factor. One further aspect of the invention relates to an electronic ballast (1) which has a circuit arrangement (14a, 14b) according to the invention.

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 lamp contains a lamp voltage conversion circuit within the lamp and connected to a lamp terminal. The voltage conversion circuit includes a phase-control clipping circuit that clips a load voltage and provides an RMS load voltage to the lamp. The phase-control clipping circuit has a time-based pulse source that triggers conduction of the phase-control clipping circuit independently of line voltage magnitude.

Abstract: A method (700) for protecting a ballast from an output ground-fault condition includes the steps of applying power to the ballast (step 710), providing a startup delay period for a DC-to-DC converter (step 730), monitoring a voltage across a DC blocking capacitor (step 740), preventing startup of the DC-to-DC converter in response to the voltage across the DC blocking capacitor being greater than a threshold value during the startup delay period (step 750), and allowing startup of the DC-to-DC converter in response to the voltage across the DC blocking capacitor being less than the threshold value throughout the startup delay period (step 760). Preferably, the steps of monitoring (step 740), preventing (step 750), and allowing (step 760) are implemented by a microcontroller, and the DC-to-DC converter is preferably implemented as either a Sepic converter or a buck converter.

Abstract: A phase-control power controller that converts a line voltage to an RMS load voltage includes a fixed phase forward/reverse hybrid phase-control clipping circuit that performs phase-control clipping of a load voltage to provide an RMS load voltage. A conduction angle of the phase-control clipping circuit is defined by a time-based pulse source that triggers conduction in the phase-control clipping circuit independently of line voltage magnitude during time periods that span polarity changes of the load voltage and that are separated by intervals when conduction is not triggered. The phase-control clipping circuit includes a transistor switch whose gate receives positive polarity signals from the time-based pulse source to trigger conduction of the phase-control clipping circuit. The power controller may be in a voltage conversion circuit that converts a line voltage at a lamp terminal to the RMS load voltage usable by a light emitting element of the lamp.

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: A voltage converter, whose topology can be switched over between a boost converter and a SEPIC. The boost converter has ripple current compensation. As a result, the inductors used can be utilized in optimum fashion. A thyristor which is protected against breakdown triggering by a negative gate voltage is used as the changeover switch.

Abstract: A stem and lamp capsule are connected together as an assembly using a retainer such that the stem is clamped to one end of the retainer and the capsule is clamped to the other end of the retainer. An oxidizable fuse is connected between leads of the capsule and electrical conductors of the stem. The retainer maintains the rigidity of the assembly and keeps a constant distance between the stem and the lamp capsule so that the repeatability and failure parameters of the fuse length can be maintained within acceptable tolerance.

Abstract: An illumination system has at least two light sources of which at least one light source includes an LED, and a driver device designed to operate at least the one LED with a DC signal; a sensor device for determining at least one feature of the light output; an actual value storage device connected to the sensor device for storing an actual value of the feature; a setpoint selection device for storing a setpoint of the feature; and a control device connected on the input side to the actual value storage device for of transmitting the actual value, and to the setpoint selection device for transmitting the setpoint, and which provides the driver device with a control signal that changes a characteristic of the DC signal used for driving the LED such that the actual value approaches the setpoint.