A modulation engine for a light-emitting-diode (LED) driver is described that includes an output port, a charge current source, a discharge current source, and an output control unit. The output control unit is configured to generate a modulation signal (e.g., a pulse-width-modulation signal) at the output port by at least alternating, based on a duty cycle of the modulation signal, between coupling the charge current source to the output port and the discharge current source to the output port to linearly shape the charge at the output port in accordance with the duty cycle.

A control circuit of a driving circuit for supplying a driving current to a light source includes: a pulse width modulation (PWM) input terminal configured to receive an input dimming pulse having an input duty ratio corresponding to a target light quantity of the light source, the input dimming pulse being pulse-width modulated; and a dimming controller configured to convert a period and a pulse width of the input dimming pulse into digital values, reconvert the digital values into an output dimming pulse having an output duty ratio which is the same as or different from the input duty ratio, and control the driving current to be on and off based on the output dimming pulse.

A lighting control circuit for an illuminating lamp includes: a rectifier part that is connected to a ballast to which commercial alternating-current electric power is supplied, and converts the alternating current to direct current; a smoothing capacitor that is provided on an output side of the rectifier part, and removes an alternating-current component included in direct current outputted from the output side; a drive circuit that has a switching element, and performs on-off control on electric current flowing to a plurality of solid-state light-emitting elements connected in series to both ends of the smoothing capacitor; and an inductor that is provided in an electric power supply system between the ballast and the smoothing capacitor.

Method for controlling a plurality of luminaire units with at least one dedicated light source, and at least functionally connected control entity incorporating a wireless transceiver, the luminaire units configured to communicate via a mesh network established utilizing the wireless transceivers thereof, wherein at least one of the luminaires is electrically connected to a user-operable switch device for controlling the luminaire, the method including detecting, at the at least one luminaire, signal triggered by switching action, determining, in response to the detection, at the at least one luminaire unit a control action of the at least one light source and a message to be wirelessly transmitted in the mesh network to enable other luminaire units in the network to execute a responsive luminaire control action as configured in the control logic entities thereof based on the captured message, and executing the control action and transmission of the message.

According to one aspect, a load control system responsive to electric power from either a first power source or a second power source operable during first and second time periods, respectively, comprises a first circuit responsive to the first and second power sources to develop power waveforms having different characteristics during the first and second time periods. The load control system further includes a second circuit coupled to the first circuit and responsive to the characteristics of the power developed by the first circuit for developing first and second different outputs during the first and second time periods, respectively.

The disclosure regards to drivers and driving methods for a LED string consisting of LEDs. The LED string and a current switch are coupled in series between a power line and a ground line. The power line is powered to regulate a signal representing a current passing through the LED string. An enable signal capable of switching the current switch is provided. Whether a predetermined event occurs is detected. When the predetermined event occurs, the enable signal is clamped to have a predetermined logic value, the current switch thereby being kept either open or short.

An LED driver IC for driving external strings of LEDs includes a prefix register and a data register connected in series with each other and with the prefix and data registers in other driver ICs. The prefix and data registers of the driver ICs are connected in a daisy chain arrangement with an interface IC. The interface IC loads data identifying a functional latch into the prefix register and data defining a functional condition into the data register of each driver IC. The data in the data register is then transferred to the functional latch to control the functional condition within the LED driver IC.

In various embodiments an apparatus configured to be connected to a lighting network and to control a first and a second lighting unit in response to at least one signal received via the lighting network is disclosed. In one example, the apparatus comprises a processor configured to receive an identification command, and in response thereto to execute an algorithm for communicating a network address associated with the apparatus, the algorithm comprising sequentially, for each bit of the network address: controlling the first lighting unit, to indicate a value of the bit by the lighting unit entering a state corresponding to the value of the bit, and causing the second lighting unit, to signal that the first lighting unit validly indicates the value of the bit and causing the second lighting unit to enter a state which indicates an end of the network address.

An LED AC drive circuit, comprising: a rectification unit, a current-limiting unit, M LED units and M−1 connected/disconnected control connection lines; each LED unit comprising ni LEDs connected in series, wherein 1≦i≦M, and n1+n2+ . . . +nM=N, 1≦M≦N, and N is determined by formula (I). The M LED units are connected sequentially to the positive end of the rectification unit and to the current-limiting unit connected to the negative end of the rectification unit; the first LED unit comprises switches connected in series at the negative end of the LED string; the ith LED unit comprises switches connected in series at the positive end of the LED string and switches connected in series at the negative end of the LED string, wherein 1≦i≦M−1; and the Mth LED unit comprises switches connected in series at the positive end of the LED string.

Flexible light engines capable of being cut, and methods thereof, are provided. A cuttable flexible light engine includes a flexible strip and strings of solid state light sources coupled in parallel. A voltage balancer establishes a desired current flow through the strings of solid state light sources when the flexible strip is cut to a desired length, and may be part of a connector placed where the strip is cut. The strings may be provided in a first set of strings coupled in parallel between a first conductive path and an intermediate conductive path and a second set of strings coupled in parallel between the intermediated conductive path and a second conductive path. A cuttable flexible light engine may also include test points positioned within the strings.