Abstract: Systems and techniques for identifying that a load associated with a lamp is absent from a circuit is described. A method, for example, includes receiving output of a circuit having at least two loads associated with a lamp and an anti-parallel transformer, monitoring, based on the output, a resistance of the anti-parallel transformer with respect to a threshold corresponding to the associated loads, and identifying that either the first of the associated loads or the second of the associated loads is absent from the circuit responsive to the monitored resistance crossing the threshold.

Abstract: A plurality of laser diode units is tested in a bar state, each of the laser diode units in which a laser diode that includes a first electrode and a second electrode formed on surfaces facing each other and that is mounted on a mounting surface of a submount such that the first electrode faces the mounting surface of the submount.

Abstract: The invention relates to a system for recording characteristic curves for a light-emitting diode arrangement (1) comprising at least one light-emitting diode (2). A control unit (4) is used to operate the light-emitting diode arrangement (1) and to record the diode current (8) and the voltage (9) on the light-emitting diode arrangement (1). The control unit (4) is also used to record a first current/voltage pair (P1) and a different second current/voltage pair (P2), at a first temperature of the light-emitting diode arrangement (1), and a third current/voltage pair (P3) and a different fourth current/voltage pair (P4), at a second temperature of the light-emitting diode arrangement (1). The invention also relates to a method for recording characteristic curves of a light-emitting diode arrangement.

Abstract: Methods to identify a fluorescent lamp among multiple fluorescent lamps include: receiving input to a circuit including multiple fluorescent lamps operated by corresponding multiple control signals, each fluorescent lamp configured to output radio frequency (RF) signals in response to receiving a detection signal, the input to identify which first control signal is provided to a first fluorescent lamp; in response to receiving the input, providing a first discovery signal in place of each control signal provided to each fluorescent lamp, one fluorescent lamp at a time; determining that the first fluorescent lamp outputs RF signals; and identifying the control signal that was replaced with the detection signal that caused the first fluorescent lamp to output the RF signals.

Abstract: A method is provided for operating at least one LED by a switched-mode regulator circuit to which a DC or a rectified AC voltage is supplied and which provides a supply voltage for at least one LED by a coil and a switch clocked by a control/regulation unit. When the switch is activated, power is temporarily stored in the coil and is discharged through a diode and through at least one LED when the switch is deactivated and the current flows through the LED through a first power storage element which is coupled to a second power storage element. The first power storage element just reaches its maximum capability of storing power due to the current flowing through the LED. A rising current is supplied to the second power storage element such that the time can be detected when the first power storage element recovers its capability of storing power.

Abstract: A circuit for driving a vehicle lamp includes a current path coupled between a power line and ground, and a monitoring unit coupled to the power line. The current path includes a dummy load. The monitoring unit can monitor a testing signal applied to the power line. The testing signal can test whether the vehicle lamp operates properly. The monitoring unit can conduct the current path to enable a current to flow through the dummy load to ground to decrease a total resistance of the circuit if the testing signal is detected.

Abstract: An organic electroluminescence device is provided, which comprises: a lighting region, a wiring region, a bonding region and a wiring extending region (300), the lighting region comprises an anode, an organic functional layer, a cathode; the wiring region comprises wirings connecting the anode and cathode with a driving chip or a circuit board; the bonding region is a region in which the wirings connect with the driving chip or the circuit board; the ends of the wirings locate in the wiring extending region, the wirings in the wiring extending region are parallel with the wirings in the wiring region or form an angle with the wirings in the wiring region. A method for testing the organic electroluminescence device is also provided. With improving the wiring arrangement of the organic electroluminescence device, it is easier and more accurate to press bond a conductive adhesive tape and the wirings, and, the row wirings and the column wirings are protected from being shorted during screen testing.

Abstract: A device can be used for detecting failures in an illumination device having a plurality of light emitting diodes connected in series. A first circuit node, a second circuit node, and a third circuit node interface the illumination device such that a voltage supplying the plurality of light emitting diodes is applied between the first and the second circuit node and a first fraction of the supply voltage drop is provided between the third and the second circuit node. An evaluation unit is coupled to the first circuit node, the second circuit node, and the third circuit node and configured to assess whether a voltage present at the third circuit node is within a pre-defined range of tolerance about a nominal value that is defined as a second fraction of the supply voltage present between the first and the second circuit node.

Abstract: A short detection circuit includes a voltage divider circuit, for generating, according to a bottom voltage of one or more light-emitting diode strings, a divided voltage less than the bottom voltage. Additionally, the short detection circuit includes a voltage clamp circuit, coupled to the voltage divider circuit, for clamping the divided voltage, and a comparator, coupled to the voltage divider circuit, for comparing the divided voltage and a reference voltage, to decide whether a short circuit occurs in the one or more light-emitting diode strings according to a result of the comparison.

Abstract: In an organic EL panel inspection method, to determine whether an organic EL panel is good or bad, a plurality of voltages having different values are sequentially applied to the organic EL panel, thereby measuring the respective currents. According to the currents, the following three criteria are checked: criterion (1), whether or not a spike current is present in the measured currents, criterion (2), between when the plurality of voltages are sequentially applied from one direction to the other direction of the voltage and when the plurality of voltages are sequentially applied from the other direction to the one direction, whether or not currents having different current densities occur at the same voltage, and criterion (3), the absolute value of the current density of current flowing when a predetermined voltage in the reverse direction is applied to the organic EL panel.

Abstract: An electronic ballast for driving a gas discharge lamp comprises an inverter circuit, a resonant tank circuit, and a control circuit operable to determine an approximation of a resonant frequency of the resonant tank circuit and to control the inverter circuit in response to the approximation of the resonant frequency. The control circuit determines the approximation of the resonant frequency by adjusting an operating frequency of a high-frequency inverter output voltage provided to the resonant tank circuit from a frequency above the resonant frequency down towards the resonant frequency, measuring the magnitude of a lamp voltage across the lamp, and storing the present value of the operating frequency as the resonant frequency when the magnitude of the lamp voltage reaches a maximum value. The control circuit may control the operating frequency of the inverter output voltage in response to the approximation of the resonant frequency and a target intensity of the lamp.

Abstract: A system and method of quantifying color and intensity of light sources including LEDs, HBLEDs (High Brightness LEDs), and other Solid State Lights (SSLs) using C-parameters to model a Spectral Power Distribution (SPD) to improve precision, accuracy, repeatability and usefulness of measurement of optical properties of wavelength and radiant flux in manufacturing of an object, designing products and processes that use the object, and describing/defining the object, is provided.

Abstract: Method to identify a current drawn by a fluorescent lamp in a circuit. Methods include receiving a voltage supplied to a fluorescent lamp drawing a current in response to the voltage, digitally sampling the voltage at a sampling frequency and associating a first time stamp with a voltage value representing one of a maximum or minimum value in observed voltage, receiving the current after receiving the voltage, digitally sampling the current at the sampling frequency and associating multiple second time stamps with a corresponding multiple current values, identifying a second time stamp, a difference between the first time stamp and the second time stamp being within a threshold, and identifying a current value associated with the second time stamp as the current drawn by the fluorescent lamp.

Abstract: The present invention relates to a method for inspecting a light-emitting device, the method including performing a light emission test of (A) a light-emitting device including a lead frame having mounted and packaged thereon a plurality of light-emitting elements or (B) a light-emitting device obtained by resin encapsulating and packaging the light-emitting device (A), by applying a current to the plurality of light-emitting elements and judging each light-emitting element as passed or failed, in which arrangement of the plurality of light-emitting elements in the light-emitting device is set as in the following (?): (?) In a lead frame having a lattice form including a plurality of rows and a plurality of columns with a plurality of intersection points formed thereby, a plurality of light-emitting elements are disposed between the adjacent intersection points in each row, the adjacent light-emitting elements in each row are connected to each other so that positive electrode terminals or negative electrode t

Abstract: A combination lighting tester tool. The combination lighting tester tool includes at least three independent testing tools for identifying and diagnosing a problem in a lighting system. For example, the tester includes a lamp testing function in which a high voltage test signal is generated and transmitted using an antenna. When the test signal is in proximity to a gas filled lamp, the voltage is of sufficient magnitude to ionize the gas inside the lamp, causing the lamp to illuminate. The tester also includes a ballast testing function in which the power lines or wires connecting a ballast to a lamp or lighting fixture are tested, and a filament tester for testing the filaments in a lamp for continuity or resistance. The tester also includes a worklight for illuminating an area under test and one or more display devices (e.g., LEDs, an LCD display, or the like) which provide an indication of, for example, a test being performed or a result of a test.

Abstract: An optimized light source and a method of manufacturing the same. The light source is made up of an array of individual lighting elements and is optimized for electrical, optical and economic performance, as well as a method for configuring such an array. The a process for selecting individual lighting elements is based on characterizing and sorting individual lighting elements based on performance so that the performance of the overall array is improved by combing individual lighting elements whose individual performance might not otherwise meet the performance of the overall array.

Abstract: An embodiment of the present invention relates to a method for detection of short circuit conditions in an LED array having one or more LED strings, each of which includes one or more LED devices. The method includes determining a minimum voltage that is the lowest of voltages associated with cathode terminals of the one or more LED strings. The method also includes determining if said minimum voltage is between a lower limit voltage and an upper voltage limit. If said minimum voltage is between the lower limit voltage and the upper voltage limit, then a result of a short circuit testing can be considered valid. Here, the short circuit testing includes comparing a sampled voltage associated with a cathode voltage of one of the LED strings with a short-circuit reference voltage.

Abstract: Disclosed is a circuit for detecting the presence of an inductive load. The circuit uses a voltage ringing detector to detect a voltage ringing signal across the inductive load and a signal generator for generating a signal indicating the presence of the inductive load upon detection of the ringing signal. The circuit may be used in a dimmer circuit for controlling the load. The circuit may be used as a load detector for a universal dimmer or may be used in a protection circuit for circuits not designed to control inductive loads.

Abstract: A lighting device including a test device for testing the proper operation of a primary and a secondary power supply alternatively providing electrical power to the light. The test device is attached to a bracket using a single fastener such as a nut and the bracket is attached to a receptacle for the light using a different single fastener, such as a pop-rivet or screw.

Abstract: A circuit for monitoring the functionality of an electrical element. A primary power supply provides direct current to the electrical element at a current sufficient for the electrical element to operate. A Schottky diode is disposed between the primary power supply and the electrical element, wherein the electrical element draws its operational current through the Schottky diode when in operation. A reverse bias power supply is provided. An opto-isolator is disposed between the reverse bias power supply and the electrical element. The electrical element draws a secondary current from the reverse bias power supply through the opto-isolator. The opto-isolator creates an output signal that is indicative of the secondary current. The output signal is used to control a remote failure indicator. When the electrical element fails, the current flowing through the opto-isolator stops. This triggers the failure indicator and informs a user as to the failed status.

Abstract: A device for measurement of characteristic parameters of at least one assembly of at least one light emitting diode (LED) comprising a measurement circuit for each assembly, wherein the measurement circuit has an electrical input which can be connected to the LED, a single measurement output to provide electrical values which are representative of at least two characteristic parameters of the LED, a first circuit configuration, which is designed to provide the measurement output with a value which is representative of a first characteristic parameter, a second circuit configuration, which is designed to provide the measurement output with a value which is representative of a second characteristic parameter and means for switching between the first circuit configuration and the second circuit configuration.

Abstract: An electro-optical device includes a substrate, a plurality of unit circuits that includes a plurality of scanning lines, a plurality of data lines and electro-optical elements provided corresponding to intersecting regions of the scanning lines and the data lines and is formed in a display region of the substrate, a plurality of pixel circuits that includes electro-optical elements and is formed in the display region and a sealing member that seals the electro-optical elements of the plurality of pixel circuits formed in the display region and is attached to the substrate, wherein a test circuit is formed between an attaching region at which the sealing member is attach to the substrate and the display region.

Abstract: A light emitting diode (LED) based illumination module performs on-board diagnostics. For example, diagnostics may include estimating elapsed lifetime, degradation of phosphor, thermal failure, failure of LEDs, or LED current adjustment based on measured flux or temperature. The elapsed lifetime may be estimated by scaling accumulated elapsed time of operation by an acceleration factor derived from actual operating conditions, such as temperature, current and relative humidity. The degradation of phosphor may be estimated based on a measured response of the phosphor to pulsed light from the LEDs. A thermal failure may be diagnosed using a transient response of the module from a start up condition. The failure of LEDs may be diagnosed based on measured forward voltage. The current for LEDs may adjusted using measured flux values and current values and a desired ratio of flux values. Additionally, the LED current may be scaled based on a measured temperature.

Abstract: An exemplary testing device for testing quality of indicator lights includes a light intensity tester and a control unit electrically connected to the light intensity tester. The light intensity tester includes a testing circuit, and the testing circuit is capable of generating testing parameters of corresponding indicator lights. The control unit is capable of providing electric energy to the indicator lights. The testing parameters from the testing circuit are changed according to light intensity of the indicator lights and are then transmitted to the control unit. Thus, the control unit is capable of comparing the testing parameters with predetermined parameters to detect the quality of the indicator lights.

Abstract: A projector lamp electronic test circuit is provided. The test circuit includes an electrical connector configured to be operatively coupled to a lamp of a projection unit under test, a converter configured to receive a test charge to be sent to the lamp from an alternating current power source, the converter configured to convert the test charge from alternating current to direct current, and an autotransformer operatively coupled to the converter, the autotransformer configured to regulate a voltage of the test charge, the voltage being suitably high enough to cause failure of the lamp.

Abstract: Apparatus and methods for testing a light fixture power circuit are therefore provided. The light fixture power circuit may energize a fluorescent lamp by providing power at first and second power terminals. The lamp holder may include a lamp pin guide for guiding the tube's contact pins toward the first and second power terminals. The apparatus may have probes that simulate the tube's contact pins. The probes may be robotically inserted into the lamp holder in a manner that is similar to the manner in which the contact pins would be inserted. This may eliminate the requirement to use fluorescent tubes to test the light fixture power circuit. The apparatus may include circuitry for testing the impedance of the light fixture power circuit at the first and second power contacts.

Abstract: The invention relates to the operation of illuminants, in particular OLEDs. The invention relates to a method and a measuring instrument for determining the electrical properties of an OLED, the equivalent circuit diagram of which is composed of the parallel connection of an equivalent diode DE and an equivalent capacitance CE as well as an equivalent resistance RE that is connected in series to said parallel connection. The values for the equivalent resistance RE and the equivalent capacitance CE are determined at a different time than are the values for the equivalent diode DE.

Abstract: System(s) and method(s) are provide to efficiently assess performance of a set of light emitting diode (LED) strings in an illumination system. A multiplexer component collects input signal from the one or more LED strings via a first set of one or more monitoring pins, processes the collected input signal, and extracts at least one output signal. The at least one output signal is conveyed to a demultiplexer component through a second set of one or more monitoring pins, wherein the number of elements in the second set of monitoring pins is equal to or smaller than the number of monitoring pins in the first set. The collected input signal is processed in accordance with at least one mode of operation of the multiplexer component, the mode of operation autonomously configured by the demultiplexer component. The multiplexer component can autonomously generate intelligence on operating status of the set of LED strings.

Abstract: A generator generates electricity by non-combustion means. A battery stores the generated electricity. An electrical appliance is powered by the stored electricity. A metering device tallies an operating parameter indicative of the amount of electrical energy consumed by the appliance. A housing supports the generator, the battery, the appliance and the metering device. A device, including the generator, the battery, the metering device and the housing, is manually portable.

Abstract: The condition of a lamp (1) for heating blank bodies made of thermoplastic material, intended for the manufacture of containers by blow moulding or stretch-blow moulding, is detected. The infrared electromagnetic radiation lamp has an envelope (2) made of glass or quartz enclosing a filament (3); the lamp is provided with an electrically conductive element (6) mechanically integral with the envelope; the conductive element is made electrically live and an electrical variable is continuously detected between the terminals of the conductive element when the lamp is in operation; and data representative of the condition of the conductive element, and of the envelope, is supplied.

Abstract: An apparatus and method for detecting lamp failure is described for an array of lamps used in a rapid thermal processing system. The lamp failure detection system enables identification of a failed lamp among a plurality of lamps, and also provides identification of the failure type. The apparatus applies a lamp failure detection method to the voltage drop values measured across each lamp to determine if a lamp is in a failure state. In one embodiment, a field programmable gate array is used to apply a failure detection method to the lamp voltage values.

Abstract: An apparatus for inspecting a light emitting diode (LED) package is provided to inspect an LED to determine whether or not it is defective, and discard the LED when the LED is defective. The apparatus for inspecting an LED package includes: an inspection unit inspecting an LED through a visual inspection to determine whether or not the LED is defective; and a defective product rejection unit discarding the LED when the LED is determined to be defective on the basis of inspection results from the inspection unit among LEDs supplied from the inspection unit. Because the operation of inspecting LEDs and discarding a defective LED are automated and can be rapidly processed as a sequential process, productivity can be improved.

Abstract: An apparatus and method for detecting an end of life (EOL) condition of a lamp that exhibits a re-ignition behavior. A voltage is applied to the lamp to cause the lamp to start emitting light, and a lamp re-ignition voltage to normal lamp voltage difference after a mask-off period expires is monitored. The lamp is determined to have reached the EOL condition when a predetermined percentage of high difference half cycles occur during a set number of lamp voltage half cycles that are measured during a measurement window. The method continuously monitors the lamp re-ignition voltage to normal lamp voltage difference and records whenever the lamp re-ignition voltage to normal lamp voltage difference is higher than the re-ignition difference threshold level at any lamp voltage half cycle. An EOL lamp is detected when a predetermined number of high difference half cycles occurs in a set total number of lamp voltage half cycles measured in a rolling measurement window.

Abstract: The present invention is directed to a method for remotely collecting metering information via a light emitting diode (LED) based street light. In one embodiment, the method includes collecting information from a utility meter coupled to a home, establishing a two-way communication path via a communication module to a central office, wherein the communication module is coupled to the LED based street light and sending the information from the utility meter to the central office via the two-way communication path.

Abstract: A method of determining the ageing characteristics of an LED comprises applying a current stress pulse to the LED. The LED is monitored to determine when the thermal heating induced by the current stress pulse has been dissipated to a desired level. The operational characteristics of the LED are then measured before applying the next stressing pulse. This method accelerates the effect of aging in a reproducible way and therefore is able to greatly reduce the time needed for a reliability test.

Abstract: An apparatus and method thereof for igniting and operating a high intensity discharge (HID) lamp during an in service life, and powering down the lamp when an end-of-life (EOL) lamp condition is detected. The apparatus and method defines a series of thresholds of lamp voltage asymmetry, or rectification thresholds, and monitors the lamp rectification from ignition through normal operation. The detection scheme is masked off for a predetermined period of time when the lamp is initially started. Thereafter, the rectification threshold of the lamp voltage asymmetry is gradually reduced over time, until a defined minimum rectification threshold level is reached and maintained. The method continuously monitors the lamp voltage and records whenever the lamp voltage asymmetry is higher than the rectification threshold level at any lamp voltage cycle.

Abstract: Inoperative or defective electroluminescent (EL) emitters in an EL display having a plurality of subpixels are detected. Current flow through a drive transistor in a subpixel is turned off, a selected test current is provided through the EL emitter in the subpixel using a current source, and the voltage at a second electrode of a readout transistor in the subpixel is measured to provide a status signal representative or characteristics of the selected EL emitter. The status signal for the subpixel is compared to the respective status signals of neighboring subpixels to determine whether the EL emitter in the subpixel is defective.

Abstract: Control of delivery of current through one or more discharge lamps. Methods include alternately switching on and off switching elements that control a fluorescent lamp, in response to receiving input, until the brightness of the lamp decreases to a threshold. Further, methods include providing control signals at complementary duty cycles to further decrease the brightness and alternating the duty cycles of the signals applied to the filaments of the fluorescent lamp.

Abstract: The present invention relates a diagnosis device for detecting an end of lamp life of a lamp, a diagnosis method, and a lamp ballast circuit using the same. The diagnosis device generates a reference lamp voltage by adding a predetermined reference voltage to a distributed voltage corresponding to a lamp voltage applied to a lamp and generates an integrated lamp voltage by integrating the reference lamp voltage. The diagnosis device compares the integrated lamp voltage with a normal range that an integrated lamp voltage has when the lamp is in a normal state.

Abstract: A circuit for driving a vehicle lamp includes a current path coupled between a power line and ground, and a monitoring unit coupled to the power line. The current path includes a dummy load. The monitoring unit can monitor a testing signal applied to the power line. The testing signal can test whether the vehicle lamp operates properly. The monitoring unit can conduct the current path to enable a current to flow through the dummy load to ground to decrease a total resistance of the circuit if the testing signal is detected.

Abstract: A lamp includes a generator that generates electricity. A battery stores the generated electricity. A light source produces light from the stored electricity. A metering device tallies an operating parameter indicative of the amount of electrical energy consumed by the lamp.

Abstract: A life test device comprises an oven, a current source, a voltage meter, a control module, and a process module. A light-emitting diode (LED) is disposed in the oven. The temperature of the oven is gradually changed in a first period and remains at a set temperature in a second period. The current source provides a first current and a second current to the LED. The voltage meter measures forward voltages of the LED. The control module controls the current source to output the first or second current to the LED and controls the voltage meter to measure the forward voltages of the LED. The process module calculates a junction temperature of the LED according to the forward voltages and a variation relationship formula between the forward voltages and the temperature of the oven.

Abstract: A system and method of testing High Brightness LED (HBLED) is provided, and more particularly, a system and method of Controlled Energy Testing of HBLED with improved accuracy and repeatability is provided. In one embodiment, the system includes a programmable constant power source for providing a constant power to a Device Under Test (DUT), in this case, an HBLED, wherein the programmable constant power source adjusts an output voltage or an output current to ensure that a given amount of power is supplied to the HBLED for a predetermined amount of time and to provide precise control of a junction temperature of the HBLED for the duration of the test sequences; a Parametric Measurement Unit (PMU) including a processor for executing a plurality of HBLED test sequences, and a spectrometer for measuring a set of HBLED parameters including power and color (wavelength) of an optical output of the HBLED; and a controller for coordinating timing of acquiring the set of measured HBLED parameters.

Abstract: The system consists of an LED failure detection circuit to provide protection against individual LED catastrophic failure. When LED clusters are arranged in a series-parallel configuration, it is important to detect individual LED failure in order to avoid uncontrolled luminous intensity reduction and/or light uniformity degradation. The circuit compares the voltage levels on LEDs with similar position but situated in different chains. In normal conditions, the voltage levels are substantially similar to one another. In case of individual or multiple LED failure, open or shortcircuit, the circuit sends a signal to the automatic turn off circuit that initiates the lamp forced turn off sequence.

Abstract: A life test device comprises an oven, a current source, a voltage meter, a control module, and a process module. A light-emitting diode (LED) is disposed in the oven. The temperature of the oven is gradually changed in a first period and remains at a set temperature in a second period. The current source provides a first current and a second current to the LED. The voltage meter measures forward voltages of the LED. The control module controls the current source to output the first or second current to the LED and controls the voltage meter to measure the forward voltages of the LED. The process module calculates a junction temperature of the LED according to the forward voltages and a variation relationship formula between the forward voltages and the temperature of the oven.

Abstract: A testing device (1) for a lamp (3) operated at a nominal voltage (Vn) and at a nominal frequency (fn), having a capacitive coupling of a test voltage (Vp) at a testing frequency of (fp) to the lamp (3), wherein a coupled test voltage (Vpa) corresponds to the nominal voltage (Vn), and a coupled test frequency (fpa) corresponds to the nominal frequency (fn). The testing device is capable of testing a gas-filled lamp having integrated upstream electronics between power supply connections and a gas filled portion.

Abstract: A method of determining the dominant output wavelength of an LED, comprises determining an electrical characteristic of the LED which is dependent on the voltage-capacitance characteristics, and analysing the characteristic to determine the dominant output wavelength.

Abstract: Various embodiments provide a method for ascertaining a type of a gas discharge lamp using an electronic ballast for operating different types of gas discharge lamps, wherein the different types of gas discharge lamps differ in at least one operating parameter, wherein the method may include: a) preheating at least one filament in the gas discharge lamp for a predetermined preheating time; b) measuring a physical variable which is characteristic for the type of the gas discharge lamp at the end of the preheating time and providing the measurement value of said variable; and c) ascertaining the lamp type on the basis of the measurement value which is provided, wherein the preheating time is increased by a predetermined time period and the b) and c) are repeated if the lamp type in c) cannot be ascertained uniquely. Moreover, various embodiments provide an electronic ballast for operating at least two different types of gas discharge lamps which have at least one different operating parameter.

Abstract: The present invention is directed to a method for remotely monitoring and controlling a light emitting diode. In one embodiment, the method includes establishing a two-way communication path via a communication module to a central office, wherein said communication module is coupled to said LED based street light and sending information related to the LED based street light to the central office via the two-way communication path.

Abstract: For monitoring the operation of a gas discharge lamp operated with an AC voltage, a lamp voltage signal is generated which is dependent on the voltage dropped across the gas discharge lamp during operation. The lamp voltage signal is filtered with an attenuation that is different for a DC component and for a component having the frequency of the AC voltage, whereupon a positive and negative peak value of the filtered lamp voltage signal are determined. For monitoring the gas discharge lamp, an average value of the two peak values is determined and compared with a limit value, and a difference value between the two peak values is determined and compared with a limit value.