Abstract: A power converter powers an LED fixture from a power supply, and comprises a primary circuit a primary winding; and a switch in series connection with the primary winding to in a conductive state of the switch connect the primary winding to the power supply; a secondary circuit comprising a secondary winding that is magnetically coupled with the primary winding for providing power to the LED fixture in response to a switching of the switch; the power converter further comprising: the power converter further comprising: a sensing circuit configured to generate a signal representative of the output voltage of the secondary winding, an edge of the signal representing an edge of the output voltage of the secondary winding in response to the switching of the switch; and a detecting circuit configured to derive timing data from the edges of the signal, to estimate a load of the power converter from at least one output parameter of the power converter, and to determine a momentary value of a voltage of the

Abstract: An LED light unit comprises an LED assembly and a light sensor to measure light emitted by the LED assembly and having a measurement range; a current source to drive the LED assembly at an LED current A control device is configured to: pre-heat the LED assembly by driving the current source to operate the LED assembly at an operating current; the LED assembly thereby illuminating the light sensor at a light level above the measurement range; interrupt operating the LED assembly during a stray light measurement time; and read an output signal of the light sensor; operate the LED assembly at a measurement current, to emit light at a measurement level; subtract the output signal of the light sensor during the stray light measurement time from the output signal of the light sensor during the light measurement time to obtain a stray light corrected light measurement signal; scale the stray light corrected light measurement signal by a scaling factor based on a ratio of the operating LED current and the measurem

Abstract: The present invention pertains to a system and method for operating at least one LED unit of lighting grid comprising a plurality of LED units, wherein the LED units are configured to transmit a VLC signal including a code word. A plurality of user equipment devices captures the light transmitted by the LED unit and determines parameters related to the light, such as a VLC quality parameter, flicker value, light intensity parameter and light colour parameter. Based on these parameters, a controller determines control parameters for the LED unit. As such, a feedback loop is created wherein the LED unit is controlled based on measurements with the user equipment devices.

Abstract: An LED driver comprises a current source and a power supply configured to provide a power supply output voltage to the current source. The LED driver further comprises a controller configured to measure a voltage drop over the current source and to generate a feedback signal in response to the measured voltage drop. The power supply comprises a power supply regulator configured to regulate the power supply output voltage of the power supply between a minimum power supply output voltage and a maximum power supply output voltage, the power supply regulator comprising a power supply regulator input. The feedback signal is provided to the power supply regulator input, in a range from a first feedback signal value representing a minimum power supply output voltage to a second feedback signal value representing a maximum power supply output voltage.

Abstract: An LED driver configured to power a plurality of LEDs having a different colour or colour spectrum is described, the LED driver comprising: a power converter configured to supply power to the plurality of LEDs and a control unit, the control unit comprising: an input terminal configured to receive an input signal representing a desired colour set-point; a processing unit configured to: determine a MacAdam ellipse for the desired colour set-point; determine a required intensity or current for each of the plurality of LEDs so as to achieve the desired colour set-point; determine a colour shift direction for the colour set-point, based on the determined required intensities or currents; select a modified colour set-point based on the colour shift direction and the MacAdam ellipse; determine a required supply current for each of the plurality of LEDs so as to achieve the modified colour set-point; determine a control signal for the power converter so as to generate the required supply currents; and wherein

Abstract: A method of transferring power and data between a first circuit and a second circuit is described, whereby the second circuit comprises a processing unit having an I/O terminal and an electric energy storage element, the electric energy storage element being configured to be charged by the first circuit via the I/O terminal and configured to power the processing unit, the method comprising: establishing a wired communication link between an I/O terminal of the first circuit and the I/O terminal of the second circuit; operating the I/O terminal of the second circuit as an output terminal and the I/O terminal of the first circuit as an input terminal; transmitting data via the I/O terminal of the second circuit to the I/O terminal of the first circuit by modulating an output level of the I/O terminal of the second circuit between a high level and a low level; determining whether the output level of the I/O terminal of the second circuit corresponds to the high level or the low level and, when the output leve

Abstract: Method of controlling an LED fixture comprising a plurality of LEDs, the plurality of LED comprising at least four LEDs, configured to emit light of different colors, the method comprising: receiving a set point representing a desired color and intensity for the light to be generated by the LED fixture; determining, based on available color characteristics of the plurality of LEDs, at least two different subsets of the plurality of LEDs and a set of intensity set points for each of the at least two different subsets, wherein each set of intensity set points results in obtaining or approximating the desired color and intensity by the LED fixture; selecting the subsets of the plurality of LEDs with the corresponding sets of intensity set points which meet a predetermined criterion; use a selected subset to drive the plurality of LEDs with the corresponding set of intensity set points.

Abstract: A modular system comprising a first component comprising an LED driver and is second component comprising a light engine is described.

Abstract: According to a first aspect of the invention, a control circuit and method are provided for a controlled start-up of N LED groups, wherein the control circuit comprises a LED switching element and a chargeable element in parallel with each LED group, and a low-power source, and wherein the method comprises a step of prior to supplying power to the LED groups, setting the LED switching elements in a second state which corresponds with the LED group being off, by charging the chargeable elements with the low-power source. According to a second aspect a control circuit and method are provided for controlling X LED groups, wherein the control circuit comprises a LED switching element and a chargeable element in parallel with each LED group, wherein the top of a lower chargeable element is connected via a diode with the top of a higher chargeable element.

Abstract: An LED driver for driving a plurality of LEDs or LED groups to transmit light in a VLC mode is described, wherein the LED driver comprises a control unit that is configured to: receive, at an input terminal, a set-point representing a desired illumination characteristic and data that is to be transmitted using VLC; determine a current profile for each of the plurality of LEDs or LED groups to generate the desired illumination characteristic, whereby an envelope of the combined current profile comprises a modulation in order for a corresponding intensity modulation as perceived by a sensor to represent a variable length VLC code representing the data, the VLC code comprising code words, a code word comprising a plurality of symbols; generate one or more control signals to drive the plurality of LEDs in accordance with the current profiles in order for the plurality of LEDs or LED groups to transmit the VLC code; and upon receipt of a further set-point representing a different illumination characteristic dur

Abstract: An LED driver has outputs to drive LEDs in groups of different colour temperatures. An input is configured to receive setpoint information, and a control device is configured to determine a combined LED setpoint intensity for the groups and a combined LED setpoint colour temperature for the groups, from the LED setpoint information. If the LED setpoint intensity is above a threshold, the control device operates the LED driver outputs to mix the LED group outputs to jointly achieve the LED setpoint intensity and the LED setpoint colour temperature. If the LED setpoint intensity is below the threshold, the control device selects a single LED group, operates the LED driver output associated with the selected LED group to drive that one LED group at the LED setpoint intensity, and operates the remaining LED driver outputs to drive the remaining LED groups at zero LED intensity.

Abstract: A method of replacing one of a light module and a driver module of a light unit includes reading a VLC code from a data storage memory of one of the light module and the driver. The visible light communication (VLC) code is transferred, via a connection between the light module and the driver module, and stored in the other one of the light module and the driver module. One of the light module and the driver module is elected for replacement. The VLC code from the other one of the light module and the driver module is transferred to the replaced one of the light module and the driver module. The transferred VLC code is stored in the data storage memory of the replaced one of the light module and the driver module.

Abstract: A modular system includes an LED driver, including a switched mode power converter configured to output a supply current and a first control unit configured to control a switch of the switched mode power converter, and a light engine, including an LED assembly configured to receive the supply current, the LED assembly including a plurality of LEDs and one or more switches arranged in series or in parallel with one or more LEDs of the plurality of LEDs, and a second control unit configured to control the one or more switches of the LED assembly. The first control unit is configured to control an amplitude of the supply current. The second control unit is configured to control a duty cycle of the LED current through the plurality of LEDs.

Abstract: A power converter for supplying an output voltage or an output current for powering an LED fixture is described, the power converter comprising: a primary circuit comprising: an input terminal for receiving a supply voltage; a primary winding connected to the input terminal; a secondary circuit comprising a secondary winding that is magnetically coupled with the primary winding for providing the output voltage or output current; the power converter further comprising: a sensor for measuring an electrical characteristic of the secondary circuit and; a detector configured to determine an electrical characteristic of the supply voltage based on the measured electrical characteristic of the secondary circuit.

Abstract: The invention relates to a method for changing the identification code of a light source in a visible light communication system, which visible light communication system comprises the light source, a driver system to drive the light source, and a server that is not able to communicate directly with the driver system, and which method makes use of a first mobile device comprising an image sensor, a processing unit, a network adapter, and a transmitter, wherein the processing unit is configured to process an output of the image sensor, wherein the processing unit is configured to communicate with the server via the network adapter, and wherein the processing unit is configured to send signals to the driver system using the transmitter, said method comprising the following steps: a. receiving a signal from the server by the network adapter of the first mobile device, said signal comprising a command to change the identification code of the light source from a first ID code to a second ID code; and b.

Abstract: A method of replacing one of a light module and a driver module of a light unit includes reading a VLC code from a data storage memory of one of the light module and the driver. The visible light communication (VLC) code is transferred, via a connection between the light module and the driver module, and stored in the other one of the light module and the driver module. One of the light module and the driver module is elected for replacement. The VLC code from the other one of the light module and the driver module is transferred to the replaced one of the light module and the driver module. The transferred VLC code is stored in the data storage memory of the replaced one of the light module and the driver module.

Abstract: A control unit for a LED assembly includes a first and second LED unit, the LED units being serial connected. The LED assembly, in use, is powered by a switched mode power supply. The control unit being arranged to receive an input signal representing a desired output characteristic of the LED assembly, determine a first and second duty cycle for respective LED units associated with a nominal current of the switched mode power supply, for providing the desired output characteristic, determine the largest of the first and second duty cycles for respective LED units, determine a reduced current based on at least the largest of the duty cycles, adjust the first and second duty cycle for respective LED units based on the reduced current, and provide an output signal for the LED assembly and the switched mode power supply based on the adjusted first and second duty cycles and the reduced current for obtaining the desired characteristic.

Abstract: An LED fixture includes at least one LED; an electrical power terminal, electrically connected to the LED, the electrical power terminal for electrically connecting the LED to an LED driver, a storage device for storing data in relation to the LED, and a data processing device, electrically connected to the storage device for storing data in the storage device and reading data therefrom, the data processing device being arranged and connected for providing data communication via at least one of the electrical power terminal and the LED.

Abstract: A light unit driver comprising a plurality of light unit driver channels, each light unit driver channel being configured for driving a respective light unit via a respective light unit driver channel output of the light unit driver channel, —a supply rail that is connected to respective power inputs of the light unit driver channels to conduct electrical energy to the light unit driver channels, —a backup energy storage configured for storing electrical energy, —a control device for controlling the light unit driver, The backup energy storage is electrically connected to the light unit driver channel output of one of the light unit driver channels, the light units being connected to the light unit driver channel outputs of the remaining light unit driver channels.

Abstract: The present invention relates to a lighting application, the lighting application comprises an LED assembly comprising a serial connection of two or more LED units, each LED unit comprising one or more LEDs, each LED unit being provided with a controllable switch for substantially short-circuiting the LED unit. The lighting application further comprises a control unit for controlling a drive unit and arranged to receive a signal representing a voltage level of the supply voltage, and control the switches in accordance with the signal. The invention further provides for an LED driver that enables to operate a TRIAC based dimmer at an optimal holding current and an LED driver comprising a switchable buffer, e.g. a capacitor.