Abstract: A method for converting a line voltage to an RMS load voltage in a lamp includes providing a control circuit which includes a switch and a microcontroller that operates the switch to establish an RMS load voltage for the lamp. The load voltage of the lamp is sensed and the sensed load voltage is compared in the microcontroller to a reference RMS voltage. Operation of the switch is adjusted in response to the comparison so that the RMS load voltage is substantially constant at the reference RMS voltage over a first operating range of the line voltage and so that the RMS load voltage decreases with decreasing line voltage at non-zero line voltages less than the first operating range.

Abstract: The present invention relates to mercury amalgams in discharge lamps for use at elevated operating temperatures.

Abstract: The operating method is based on the simultaneous application of FM and AM. In this process, the fundamental frequency of the AM is derived from at least one, preferably the second, longitudinal mode. In continuous operation of the lamp, the color temperature is set for a prescribed power by setting the AM degree controllably.

Abstract: A step-down controller has an input having a first and a second input terminal for applying an input voltage, an output having a first and a second output terminal at which an output voltage can be provided, a series circuit including a switch and an inductance which is coupled between the first input terminal and the first output terminal. The switch has a control input for applying a control signal. A first diode is coupled between a junction point between the switch and the inductance and a reference potential such that, when the inductance is freewheeling, a current flow through the first diode (D1) is possible. There is a snubber network with a snubber capacitor, a second and third diode and an auxiliary inductance, a series circuit including the snubber capacitor, the third diode and the auxiliary inductance being coupled in parallel with the inductance.

Abstract: The present invention relates to a circuit arrangement for operating at least one electric lamp (LP) having a drive circuit (16), which has at least one terminal for a system voltage (UN) on the input side and at least one terminal for the at least one electric lamp (LP) on the output side; the drive circuit (16) having a control unit (18) and a step-up converter having a step-up converter inductor (L2) and a switch (S1), and the control unit (18) being designed to operate the step-up converter in a discontinuous mode, in which the current (IN) through the step-up converter inductor (L2) has gaps, the duration (?t) of these gaps being varied. It also relates to an operating method for at least one electric lamp (LP) using such a circuit arrangement.

Abstract: An electrodeless lamp (10a), wherein the lamp comprises a closed-loop, tubular lamp envelope (13) with parallel cylindrical glass tubes (14a 16a) containing an arc generating and sustaining medium, means (20a) in the form of magnetic toroids for energizing the medium; and a reflector coating (22) associated with the envelope (13) and affixed thereto. In a preferred embodiment of the invention the reflector coating (22) is on the internal surface (24) of the envelope and comprises a layer of a reflective m, such as alumina. Alternatively, the reflective coating (22) can be applied to the external surface of the envelope.

Abstract: A power controller converts a line voltage to an RMS load voltage for a lamp, 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 circuit arrangement for operating at least one first and one second lamp which can be inserted in the circuit arrangement, each lamp having a first and a second filament, having a drive circuit for the purpose of driving the at least one first and second lamp, the drive circuit being designed to operate the at least one first and second lamp using a radiofrequency signal, it also includes: a comparator circuit for comparing a first and a second voltage potential within the circuit arrangement, and a deactivation apparatus for deactivating the drive circuit, the comparator circuit being designed to activate the deactivation apparatus if the difference between the first and the second voltage potential exceeds a predeterminable limit value during operation of the at least one first and one second lamp using a radiofrequency signal.

Abstract: A method of converting a line voltage to an RMS load voltage in a lamp includes modulating a load voltage with a pulse width modulation circuit that is entirely within the lamp and provides an RMS load voltage to a light emitting element of the lamp. Conduction is triggered in the pulse width modulation circuit independently of a line voltage magnitude with a time-based signal source that defines a duty cycle of the pulse width modulation circuit suitable for the RMS load voltage.

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: A circuit arrangement for operating at least one high-pressure discharge lamp having four switches in a full bridge arrangement, a first and a second switch forming the first half-bridge arm, and a third and a fourth switch forming the second half-bridge arm, at least two terminals for coupling the high pressure discharge lamp between the midpoint of the half-bridge arms, at least one terminal for supplying the circuit arrangement with a DC voltage signal, and a drive circuit for driving the four switches, the drive circuit being designed to provide a first drive signal for the switches of the arm and a second drive signal for those of the second arm in such that the drive signals are derived from a base signal whose clock pulse is swept between a first and a second frequency.

Abstract: A ballast (20) for powering one or more gas discharge lamps (70,72,74,76) comprises an inverter (200), an output circuit (300), and an arc protection circuit (400). Arc protection circuit (400) monitors an electrical signal within the output circuit (300). When an arcing condition occurs at the ballast output connections (302,304,306,308,310), the electrical signal includes a high frequency component having a fundamental frequency that is much greater than the normal operating frequency of the inverter (200). In response to the high frequency component exceeding a predetermined threshold, arc protection circuit (400) disables the inverter (200) for a predetermined shutdown period. Arc protection circuit (400) also provides a restart function for periodically attempting to ignite and operate the lamps.

Abstract: An amalgam assembly for a fluorescent lamp includes an exhaust tubulation closed at a free end thereof, a glass ball disposed in the tubulation, and a mercury amalgam body disposed in the tubulation between the glass ball and the tubulation closed end. The tubulation is provided with a pinched portion comprising a plurality of inwardly extending dimples separated from each other and adapted to engage the glass ball to retain the glass ball on a central axis of the tubulation. The glass ball rests on the dimples concentrically and gaps between the dimples allow gas to pass therethrough between the glass ball and an inside surface of the tubulation.

Abstract: An amalgam assembly for a fluorescent lamp includes a glass exhaust tubulation extending toward a base portion of the lamp, the tubulation being closed at an end adjacent the lamp base portion, and a metal cup disposed in the tubulation and retained by a pinched portion of the tubulation. The cup defines an annular outer wall having a free edge extending toward the tubulation closed end, a tubular central core portion extending toward the tubulation closed end, and an annular trough formed by the core portion and the outer wall. A mercury amalgam ball is disposed between the metal cup and the tubulation closed end, a diameter of the ball exceeding an inner diameter of the core portion, and a coating of a metal wetting agent is disposed on interior surfaces of the trough.

Abstract: An amalgam assembly for a fluorescent lamp includes a glass exhaust tubulation extending toward a base portion of the lamp, the tubulation being closed at an end thereof adjacent the lamp base portion, and a retaining structure disposed in the tubulation and retained by a pinched portion of the tubulation. A mercury amalgam body is disposed in the tubulation between the retaining structure and the tubulation closed end. The amalgam body includes lithium for wetting internal surfaces of the glass tubulation to cause the amalgam to adhere to the tubulation internal surfaces when the amalgam body is liquidized, and to thereby prevent the amalgam from flowing past the retaining structure and into the lamp envelope.