Abstract: An arc discharge lamp has an evacuated, electromagnetic-energy-transmissive envelope having therein an arc generating and sustaining medium. At least one thermionic, electron-emitting cathode is positioned within the envelope, and the cathode has an electron emissive coating thereon containing silicon carbide.

Abstract: Electronic transformers with a self-excited half bridge can be destroyed by high-voltage pulses from the mains supply lead. This can happen by the high-voltage pulse initiating a starting operation which leads to cross currents. This destruction mechanism is suppressed by specifically discharging a starting capacitor.

Abstract: The invention relates to an electronic unit having a mounting board (4) and electronic components (1-3) mounted on it, with the mounting board (4) having metal webs (41) which are embedded in an electrically insulating material (40), the metal webs (41) having a first side (411), which is in the form of a contact surface for making contact with the electronic components (1-3) and having a second side (412) facing away from this. According to the invention, cutout(s) are arranged in the electrically insulating material (40), via which the second side (412) of each metal web (41) is accessible for a voltage or current measurement apparatus.

Abstract: A mount for a fluorescent lamp that comprises a glass base with spaced-apart lead-in wires extending from therefrom. A longitudinal electrode coil containing an emitter material is mounted upon and extends between the lead-in wires. A coating of zinc oxide is provided on the ends of the electrode coil and upon the lead-in wires at least in the area where the electrode coil is mounted.

Abstract: A high-pressure discharge lamp having a discharge vessel (1) closed at two ends, the supply lead (15) near the base, and the free end (14) of the associated short supply conductor (4) being covered by a tubular cap (10) whose first end, directed toward the discharge vessel, is open, and whose second end, directed toward the base, is closed.

Abstract: The invention relates to an operating method and an operating device for at least one electric lamp (11), which device has a control input (13, 14) for prescribing a setpoint for the brightness control of the lamp (11), and a transformer (15) for transmitting the voltage impressed on the control input (13, 14) to an evaluation device (16) which serves to evaluate the voltage impressed on the control input (13, 14).

Abstract: Disconnection device for an electronic operating device for gas discharge lamps. The DC component is evaluated at a coupling capacitor (C5) specifically via a filament. Disconnection is performed in the event of filament breakage. In addition, the AC component of the generator output (O) can be monitored via a second filament, and disconnection can therefore also be performed in the event of breakage of the second filament.

Abstract: The invention relates to a method for the sampling of biphase coded digital signals by reception means which have at least one signal input having switchable signal edge sensitivity or at least two signal inputs having different signal edge sensitivity for the reception of such signals. The signals to be received are sampled precisely once per data bit, namely during the transmission of the first half-bit. The signal edges (F1-F5) of each bit are utilized for synchronizing the signal input with the control signal and for detecting transmission errors. Each signal sampling (S1-S5) is followed by a time window (&Dgr;t) within which the reception of the signal edge of the present bit is expected and evaluated as permissible. The signal edge sensitivity of the at least one signal input is set as a function of the sampled logic level of the first half-bit of the respectively transmitted bit of the signal.

Abstract: Circuit arrangement for controlling an analog voltage signal comprising an input connection for applying the analog voltage signal (UE), a digitizer unit (10) which uses the analog voltage signal (UE) to produce a digital signal (UED) which has a predetermined duty ratio when the analog voltage signal (UE) is at a nominal value, a PI regulator (12) to which, as the input signal, a nominal signal (USD) and an actual signal which is correlated with the digital signal (UED) can be supplied and at whose output a control signal (UST) for controlling the analog voltage signal (UE) can be produced, in such a manner that the control signal (UST) allows the analog voltage signal to be increased if the duty ratio is less than the predetermined duty ratio, allows the analog voltage signal to remain unchanged if the duty ratio corresponds to the predetermined duty ratio, and allows the analog voltage signal to be reduced if the duty ratio is greater than the predetermined duty ratio.

Abstract: An arc discharge lamp comprises an arc chamber having an amalgam tip attached to and communicating with it. The communication comprises a narrow tubular extension that penetrates the amalgam tip for a distance less than the depth of the tip. An amalgam that includes bismuth is contained within the amalgam tip. This construction allows operation of the lamp in any position and prevents the bismuth in the amalgam from penetrating the lamp and poisoning the phosphor.

Abstract: Flickering phenomena in gas discharge lamps are undesired in projection technology, in particular. According to the invention, the problem is solved by setting a lamp operation which does not form a focal spot. A specific control structure which includes a cascade structure and feedforward control is proposed for implementing this operation.

Abstract: A description is given of an operating method for a discharge lamp with dielectrically impeded discharges and also a corresponding ballast and illumination system. The invention is directed at withdrawing the external lamp voltage across the discharge lamp in order to produce a back ignition in the lamp by virtue of an internal counterpolarization. The back ignition improves the efficiency of the lamp operation and makes it possible to construct a very small, lightweight ballast.

Abstract: A method and apparatus for controlling a lamp ballast having a DC-DC converter with first and second MOSFETs acting as switches alternately connecting a DC power source to a power transformer, with an output of the power transformer being connected to a DC-AC inverter driving the lamp. The first and second MOSFETs in the DC-DC converter are alternately opened and closed at a frequency that is swept repeatedly between predetermined minimum and maximum frequencies. A microcontroller-based feedback element determines instantaneous power consumption by the lamp and controls the MOSFETs through a pulse width modulator to continuously adjust a duty cycle of signals driving gates of the MOSFETs to maintain a desired level of power consumption.

Abstract: A mercury capsule for use in a fluorescent lamp comprises a shell defining a chamber and a bore extending through the shell. A body of mercury is disposed in the chamber. A plug is disposed in the bore to seal the bore. The plug exhibits a melting point reached in manufacture of the fluorescent lamp, to melt from the bore to open an exit passageway for the mercury. A method for making the capsule is provided.

Abstract: A drive circuit for an LED array, comprising at least two clusters of LEDs, in which one cluster comprises a number of LEDs arranged in series which are connected to a supply voltage (UBatt), with a semiconductor switch (T) being arranged in series between each LED cluster and the associated supply voltage, which semiconductor switch (T) allows the LED current to be supplied in a pulsed manner, with a measurement resistor (RShunt) being arranged in series with the LEDs in the path for the forward current IF between the LEDs and ground. A control loop controls the semiconductor switch (T1) in a first LED cluster, referred to as the master cluster in the following text, such that a constant mean value of the LED current is achieved, wherein the master cluster has a predetermined number X of LEDs in its cluster, and with this control loop also driving at least the semiconductor switch (T2) in a further, LED cluster, referred to in the following text as the slave cluster.

Abstract: A fluorescent lamp comprises a glass tubular body defining a discharge space, and first and second electrode assemblies mounted in the discharge space in opposition to each other, each of the electrode assemblies comprising a first electrode and a second electrode. Each of the first electrodes comprises a metal lead wire with an electron-emitting material disposed on a free end thereof, and each of the second electrodes comprises a cup-shaped tube coaxially surrounding one of the first electrodes and the electron-emitting material disposed on the first electrode. The second electrode tube and the electron emitting material therein form an annular gap therebetween.

Abstract: An elongate light source (1) having at least one elongate lamp (3) with two ends, which has a light-guiding element (2; 4; 5) at at least one end.

Abstract: An electronic operating device for discharge lamps is disclosed in which an output terminal is connected via a coupling capacitor (CB) to a reference potential (E). An electric component (VC) which acts as a voltage source is inserted in series with the coupling capacitor (CB) in order to reduce the potential of an output terminal. The electric component (VC) consists in one embodiment of an inductor which is coupled to the lamp inductor.

Abstract: The invention relates to a device for controlling light sources (30-35) having a ballast (20-23) includes a set point generator for prescribing a brightness set point for the light sources (30-35), and having means for generating a control signal, dependent on the set point of the set point generator, for the purpose of brightness control of the light sources (30-35). According to the invention, the device has means for adapting the control signal to different types of light sources. The device according to the invention renders possible uniform dimming of different types of light sources which are installed in a lighting system.

Abstract: In order to heat filaments of discharge lamps, use is often made of a filament transformer (L11, L12, L13) in the associated operating devices. Particularly in the case of preheating the filaments, there is then a lack of a sufficiently high inductive component in the load current in order to ensure turn-on relief of the half-bridge switches (S1, S2) for operating devices with a half-bridge circuit. By inserting an air gap into the filament transformer (L11, L12, L13) the switch relief can be effected even in the case of preheating or of a low dimming setting.