摘要:
A method of retrieving status information of a lighting system includes propagating a command signal from a controller to a node of the lighting system by operating upstream transceivers that are upstream of the node in a transmitting mode and operating downstream transceivers that are upstream of the node in a receiving mode; propagating a reply signal including the status information of the LED unit of the node from the node to the controller by operating the upstream transceivers that are upstream of the node in a receiving mode and operating each of the downstream transceivers upstream of the node in a transmitting mode and reversing an operating mode of an upstream transceiver of a network segment from operating in a transmitting mode to operating in a receiving mode only when the downstream transceiver is operating in transmitting mode.
摘要:
A driver system for driving at least one LED, the driver system includes an LED driver including a current source connected to the at least one LED for providing an LED drive current to the at least one LED, and a control module for controlling a flow of the LED drive current through the at least one LED. The driver system further includes a power supply having a power output terminal connected to a power input terminal of the current source for providing an electrical power to the current source. The control module includes a control signal output connected to a control signal input of the power supply for controlling an operation of the power supply.
摘要:
A method of configuring an LED driver is disclosed. The LED driver being arranged to provide a supply current to an LED fixture comprising a plurality of LEDs. The method comprises: identifying the LED fixture (LF), sending via a communication network (NTW) a configuration request to a configuration database (DB), receiving configuration data from the configuration database; and configuring the LED driver (LPS) according to the configuration data.
摘要:
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.
摘要:
A method of configuring an LED driver is disclosed. The LED driver being arranged to provide a supply current to an LED fixture comprising a plurality of LEDs. The method comprises: identifying the LED fixture (LF)1 sending via a communication network (NTW) a configuration request to a configuration database (DB), receiving configuration data from the configuration database; and configuring the LED driver (LPS) according to the configuration data.
摘要:
A configurable light fixture for a lighting system is described. The light fixture comprising a receiver, wherein the receiver of the light fixture is arranged to, upon receipt of a pairing signal from a transmitter, store a transmitter ID comprised in the pairing signal in a first memory unit when the pairing signal is received within a pairing time window, the pairing time window being opened when the receiver is switched on from an off state, the receiver being arranged to, upon receipt of a control signal, compare a transmitter ID comprised in the control signal with the stored transmitter ID and release the control signal when the stored transmitter ID corresponds with the transmitter ID comprised in the control signal.
摘要:
A controller for controlling an LED assembly is described. The controller is arranged to—receive an input signal representing a required characteristic of the LED assembly,—convert the input signal to a control signal for the LED assembly,—apply a correction to the control signal to obtain a corrected control signal, the correction being based on a predetermined transient characteristic of the LED assembly,—output the corrected control signal. As such, a better correspondence between a required characteristic and an actual characteristic of the LED assembly is obtained.
摘要:
An LED driver measures a voltage across the LED and a temperature associated with the LED. The LED driver drives the LED to operate below a knee in the voltage/current curve of the LED and derives an expected voltage across the LED from the temperature of the LED, the LED driving current, and a predetermined relation between the expected LED voltage and at least one of LED temperature and LED driving current. The LED driver determines if the measured voltage across the LED exceeds the expected voltage across the LED, and establishes, based on the determination, if an LED approaching end of life warning is to be generated. Thus, an approaching end of life may be determined by the LED driver while the LED is still operational.
摘要:
A method for starting up an illuminating process of a plurality of series connected LEDs by means of a LED driver is described, whereby a maximum allowed voltage output of the LED driver is lower than a forward voltage of the plurality of series connected LEDs in a cold state. The method comprises: d) providing a first current, in value lower than a desired current, by the LED driver to the plurality of series connected LEDs, resulting in a forward voltage across the plurality of series connected LEDs lower than the maximum allowed voltage output of the LED driver, e) waiting during a predetermined wait time period, f) stepping up of the first current to a second current provided by the LED driver to the plurality of series connected LEDs.
摘要:
A modular system includes an LED driver and an LED light engine. The driver includes a switched mode power converter and a first control unit to control a switch of the converter, thereby controlling the supply current to an LED assembly of the light engine. The assembly includes LEDs and one or more switches arranged in series or in parallel with one or more of the LEDs. The light engine also includes a second control unit controlling the one or more switches of the LED assembly so as to control current through the LEDs. The first control unit controls amplitude of the supply current. The second control unit controls duty cycle of the LED current through the LEDs. The first and second control units are configured to synchronize a switching operation of the switched mode power converter with a switching operation of the switches of the light engine.