An LED backlight (15) having a plurality of LED groups (19) each including a plurality of LEDs (17) connected in series is tested. The LED groups (19a to 19c) are driven with a constant current respectively, and operating voltages (Vf1 to Vf3) of the LED groups (19a to 19c) are measured respectively. The LED backlight (15) is determined as normal when all of differences between the operating voltages (Vf1 to Vf3) are less than a reference value, and is determined as abnormal otherwise. With this, an open circuit failure and a short circuit failure of the LED (17) can be detected. A leakage failure of the LED (17) may be detected by switching an amount of a drive current used for driving with the constant current, to a minute current. Thus, the LED backlight is tested certainly and easily.

A test system is characterized by including: a holding unit that holds a light-receiving unit receiving light emitted from a test object; and an optical path forming unit that is formed with an optical transmission path as a path of the light received by the light-receiving unit, in which the optical transmission path is formed of a different member from the light-receiving unit. Since the test system has such a configuration, replacement of the light-receiving unit that receives the light emitted from the test object can be facilitated.

A controlling of a lighting network based on traffic monitoring comprises steps of determining plurality of coverage areas of set of luminaires, where each luminaire comprises at least one light source. Information related to a presence of users in said coverage areas is received. This may relate both outdoor or indoor areas and activity. A status of at least certain luminaire is then changed to a reserve status, when a last detected user exits the coverage area. Each coverage area or luminaire is providing with an expected value for the time of when the next user is expected to arrive in the coverage area of said luminaire, A set of luminaires [R] of said luminaires with the reserve status to be controlled, such as dimmed, is then defined and information related to demand response requests [D.sub.1, . . . , D.sub.n] of an electric power grid is received. In addition controlling, such as dimming, at least one of said defined set of luminaires in said reserve is performed in order to fulfill said demand response requests at least partially.

A method and apparatus for monitoring the structural health of a stock of columns such as lighting columns and/or columns within that stock each of which is connected to receive power from an external source or otherwise. The method comprises the steps of locating on an upper surface of each or a plurality of columns within the stock to be monitored a micro controller connected to receive power from the electrical source of the respective column. The micro controller includes an electronic chip or board which includes, in circuit, an accelerometer, a Wi-Fi/RF or 3G/4G component or the like and a global positioning system (GPS) component or the like. The micro controller is operable to detect and monitor the magnitude and direction of forces imposed on the respective column and the direction from which such forces are derived, and to transmit the received data to a remote server for analysis.

Systems, methods, apparatus, and machine-readable media are provided to facilitate lighting device health management. Conditions of at least a portion of an electric light assembly may be monitored with a monitor adapted to be disposed in the electric light assembly. The electric light assembly may include an electric light source and a receptacle adapted to receive the electric light source. Based on the monitoring, data recordings corresponding to operations of the electric light assembly over a period of time may be stored. Reporting data may be created based on the stored data recordings. A communication may be wirelessly transmitted with the monitor toward a system controller that is remote from the electric light assembly. The communication may include the reporting data. The monitor may correspond to the electric light source or a receptacle adapted to receive the electric light source.

Systems, methods, apparatus, and machine-readable media are provided to facilitate lighting device health management. Conditions of at least a portion of an electric light assembly may be monitored with a monitor adapted to be disposed in the electric light assembly. The electric light assembly may include an electric light source and a receptacle adapted to receive the electric light source. Based on the monitoring, data recordings corresponding to operations of the electric light assembly over a period of time may be stored. Reporting data may be created based on the stored data recordings. A communication may be wirelessly transmitted with the monitor toward a system controller that is remote from the electric light assembly. The communication may include the reporting data. The monitor may correspond to the electric light source or a receptacle adapted to receive the electric light source.

A system with which any abnormality can be easily found is provided. A system includes: a first modulator that generates a control signal and modulates an input signal in accordance with the generated control signal, to control luminance of a first light source that emits light according to the modulated input signal, the first modulator outputting the control signal; a second modulator that acquires the control signal output from the first modulator and modulates an input signal in accordance with the control signal, to control luminance of a second light source that emits light according to the modulated input signal, the second modulator outputting the control signal. The first modulator generates, as a light ID signal, a control signal for transmitting a visible light signal by luminance variations of the first light source, and acquires a light information signal being the control signal output from the second modulator.

An emergency lighting system provides testing and reporting functionality in a rapidly repeatable fashion for environments with numerous emergency lighting units. In one or more embodiments, the emergency lighting system comprises a plurality of emergency lighting units capable of conducting one or more tests and reporting their operating condition as test results. One or more terminals receive and aggregate the test results and present the same to a user. Emergency lighting units having an undesirable operating condition can then be readily identified and addressed.

A system of networked lighting devices includes a group of lighting device fixture controllers connected in a communication chain. The communication chain provides for transfer of data packets between the lighting device fixture controllers and a central controller. Each fixture controller includes a first power input that receives power from a primary power source, and a priority switch that is configured to switch the fixture controller from the primary power source to a source of DC power upon detecting failure of the primary power source. The source of DC power is sufficient to power the fixture controller and enable the fixture controller to continue to pass a stream of data to other controllers in the communication chain, but it is not sufficient to power the fixture controller's associated lighting device.

The present invention discloses a system and method for active power factor correction and current regulation in led circuit. The system (100) used in the LED driver circuit performs active PFC and current regulation through the dynamic input current wave shaping by limiting peak currents. The dynamic wave 5 shaping scheme is realized through hardware and firmware and is used to strike an optimal balance between current accuracy, Power factor, THD and peak inductor currents. The system (100) is versatile enough to improve PF and current accuracy in LED circuits and indimmers circuits.