Abstract: A light regulation device includes at least one light sensor which provides at its output a real brightness value, at least one regulator to which a set brightness value can be supplied, besides the real value, and a number n of output connections, n being greater than or equal to two. Each output connection is coupled to the output of a regulator in order to modify the light flux which can be supplied to at least one of the lighting elements. The regulator is designed to determine a difference between set and real values, to verify whether this difference lies within or outside a predeterminable tolerance range, and, in the event that the difference lies outside the tolerance range, to modify accordingly the light flux from the lighting elements which can be connected to the n output connections. At least one limit of the tolerance range depends on the actual light flux value.

Abstract: The present invention relates to a circuit arrangement for driving a gate of a transistor, in particular a MOSFET, which is arranged in an electronic ballast, the circuit arrangement (2) being designed for the variable driving of the gate (221) as a function of the operating state of the electronic ballast. The invention also relates to a method for driving a gate of such a transistor.

Abstract: A circuit arrangement for protecting an electronic converter against overloads includes: a low impedance path selectively activatable to prevent ignition of the electronic converter, the low impedance path including an electronic switch, a control capacitor whose charge voltage controls the electronic switch, whereby the electronic switch is activated to prevent ignition of the electronic converter when the charge voltage of the control capacitor is above a given threshold, a first generator for loading the control capacitor, the first generator activatable in the presence of a first overload condition of the electronic converter, and a second generator for further loading the control capacitor, the second generator activatable in the presence of a second overload condition of the electronic converter, the second overload condition being heavier than the first overload condition.

Abstract: The present invention relates to a circuit arrangement for operating at least one lamp (LA), which has a first filament (W1) and a second filament (W2), it comprising an apparatus (10) for determining a variable which is correlated with the temperature of at least one of the two filaments (W1; W2). It also relates to a method for operating at least one lamp, which has a first and second filament, a variable correlated with the temperature of at least one of the two filaments being determined prior to restarting the lamp.

Abstract: An apparatus for the closed-loop and open-loop control of filament heating for a lamp, in particular for a fluorescent lamp, has a control loop into which a first filament (W1), an operational-parameter detection element (E), a heating controller (H) and a first actuating element (S1) are connected. The heating poser of the first filament (W1) is detected by means of the operational-parameter detection element (E) and, on the basis of this, a manipulated variable (SG) is determined, by means of which this first filament (W1) is subjected to closed-loop control. Furthermore, at least one second filament (W2 to Wn), which is not connected in the control loop, is controlled on the basis of the determined manipulated variable (SG).

Abstract: The invention relates to a converter circuit having a series circuit of class E converter modules for optimizing the DC supply voltage of the individual converter module (for example C7, C11, Z1, S1, L1, L2).

Abstract: The invention relates to an operating device for operating high-pressure gas discharge lamps. Of particular concern is an operating device having a controller for start-up of high-pressure gas discharge lamps which provides a shorter start-up phase in comparison with the prior art. This is achieved by a lamp state detector which recognizes, after starting, that a hot lamp is present and thereupon increases the start-up current.

Abstract: Circuit arrangement having a free-running half-bridge inverter for operation of gas discharge lamps. A stop device is used to enable the drive to the half-bridge switches only during an on time. The oscillation frequency of the half-bridge inverter can be adjusted by the duration of the on time. This allows control of the lamp operating variables.

Abstract: The invention relates to a ballast for a high-pressure discharge lamp, in particular for a motor vehicle headlight lamp or a projection lamp, which ballast is, according to the invention, in the form of a Class E converter.

Abstract: A circuit arrangement for producing a control signal (Us) for the purpose of dimming at least one lamp, including a device (10) for modifying the phase gating angle corresponding to a dimming input value (8), it being possible for the device (10) for modifying the phase gating angle to be fed, at its input, an input signal (Ue), whose phase gating angle is to be modified, and for an output signal (U1) having a modified phase gating angle to be provided at its output; and an output at which the control signal (Us) can be provided; it also includes a device (14) for comparing the output signal (U1) with a predeterminable signal (Uc) for the purpose of producing the control signal (Us), the amplitude of the predeterminable signal (Uc) depending on the amplitude of the input signal (Ue).

Abstract: The invention relates to a method and a circuit for digital-to-analog conversion, in which an interleaved pulse-width modulation signal (VPWM) is low-pass-filtered.

Abstract: The invention relates to an operating method and an electronic ballast (EVG) for operating a light-producing apparatus (L), for example a discharge lamp. In this case, an internal timing unit in the ballast (EVG) is corrected with the aid of time information (TM) received in external signals.

Abstract: The invention relates to an electronic ballast for discharge lamps LA1, LA2 having preheatable electrodes which has a pump circuit D5/D7, D6/D8 for improving the power factor. In this arrangement, preheating is performed with a converter frequency, raised by comparison with continuous operation, and with the aid of a preheating transformer TR2.

Abstract: An electronic ballast for a lamp (16) having an input circuit (10) having a connection to a voltage supply, an output circuit (14) having a connection for the lamp (16), and a voltage converter apparatus (12), which is arranged between the input and the output circuit (10, 14), the voltage converter apparatus including an input capacitor (C1) and an output capacitor (C2), between which a switching apparatus (T1) and a freewheeling diode (D1) as well as at least one damping element (L2), at least one trapezoidal capacitor (C3) and an inductance (L1) are arranged, the voltage converter apparatus (12) being designed to carry out commutation, in each case a main circuit being defined by the current flow prior to and following commutation, at least one damping element (L2) and at least one trapezoidal capacitor (L2) being connected in series, and such a series circuit being arranged in a secondary circuit.

Abstract: The invention relates to an electronic ballast for operating a discharge lamp LA, in which a pump circuit D6, C8, C9, L1 charges an intermediate circuit capacitor C6 from the AC voltage of a converter V1, V2. A voltage limitation circuit R8, R3, D5, R4, R5, C3, SD is connected in parallel with the intermediate circuit capacitor C6. A dissipation element R8 in the voltage limitation circuit R8, R3, D5, R4, R5, C3, SD converts electrical energy into thermal energy when a maximum value for the voltage across the intermediate circuit capacitor C6 is exceeded. The current through the measuring resistor R3 is measured as the voltage UC3 across the measuring resistor R3, is detected in a delay circuit R4, R5, C3 and is used to control a shutdown device SD for the converter V1, V2.

Abstract: A lamp includes a transparent envelope having a first region defining an enclosed interior volume and a closure region adjacent to the first region, a light source in the interior volume and electrically coupled through the closure region, an interference filter coating on the exterior of the first region, and a light absorbing coating that is 7–40 nanometers thick on the exterior of the first region, except in a ring-shaped portion adjacent to the closure region that has a thickness of 50–200 nanometers.

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: A method and circuit arrangement for dimming at least one lamp, includes a connection for a supply voltage; a dimming device connected on the input side to the supply voltage and has an input for a dimming selection and at least one switch; and a filter connected to the output of the dimming device, the filter having at least one capacitor and an output for coupling to an electronic ballast; wherein it also has an input impedance modification device connected to the filter device and is designed to modify the input impedance active at the input of the filter.

Abstract: A lamp base has a plastic base part and a sprung metal ring, which is fixed to the plastic base part by webs integrally formed on the metal ring, the webs being designed such that there is a clamping fit between the webs and the plastic base part. The lamp base is preferably part of a vehicle headlamp.