Abstract: A fault detection mechanism for a LED string comprising a plurality of serially connected LEDs, the fault detection mechanism comprising: a control circuitry; and a voltage measuring means, in communication with the control circuitry, arranged to measure the voltage drop across at least one LED of the LED string, the control circuitry being operable to: measure the voltage drop, via the voltage measuring means, at a plurality of times, compare at least two of the measured voltage drops, and in the event the comparison of the at least two voltage drops is indicative of one of a short circuit LED and an open circuit LED, output a fault indicator.

Abstract: A system for powering and controlling an LED backlight, the system comprising: a control circuitry; a plurality of LED strings; a pulse width modulation functionality associated with the control circuitry and arranged to pulse width modulate a current flow through each of the plurality of LED strings; and a plurality of current limiters responsive to the control circuitry, each of the plurality of current limiters being associated with a particular one of the plurality of LED strings and operative to limit current flow of the pulse width modulated current there-through, the control circuitry being operative in the event of a thermal condition of one of the plurality of current limiters to reduce a duty cycle of the pulse width modulation functionality of the current flow through the one of the plurality of current limiters.

Abstract: A method of color control for a backlight utilizing colored light emitting diodes (LEDs), the method constituted of: providing a plurality of colored LED strings constituted of at least three different colors; lighting each of the plurality of colored LED strings to provide a backlight; providing a period wherein none of the colored LED strings are lit; obtaining during the provided period when none of the colored LED strings are lit, an indication of an ambient light; obtaining during the provided period when the colored LED strings are lit, an indication of the optical output of the colored LED strings; and controlling the lighting of the provided plurality of colored LED strings responsive to the received indication of ambient light and the received indication of the output of the colored LED strings. Preferably, the method is performed in cooperation with an on-board color sensor.

Abstract: A backlighting system comprising: a color manager; a plurality of luminaires, each of the luminaires comprising a LED string and arranged to illuminate a particular portion of a display associated therewith; a color sensor arrange to receive light from one of the luminaires; and a plurality of thermal sensors each associated with a particular luminaire and in communication with the color manager, the plurality of thermal sensors being less than the plurality of luminaires, the color manager, responsive to the plurality of thermal sensors and the color sensor, being operable to calculate color coordinates for each of the plurality of luminaires.

Abstract: A chipset for powering and controlling a plurality of light emitting diode (LED) strings. The chipset includes a controller having a pulse width modulating (PWM) functionality and a data transfer interface circuitry; and at least one dissipative active element array comprising a plurality of dissipative active elements. The dissipative active element array(s) are packaged to be thermally separate from the controller. The PWM functionality is arranged to individually pulse width modulate a current flow through each of the LED strings. Each of the plurality of dissipative active elements is associated with a particular one of the plurality of LED strings and is arranged to limit the current flow of the pulse width modulated current that flows through the particular LED string to a value, the value being responsive to a value output by the controller via the data transfer interface circuitry.

Abstract: A method of controlling the luminance of a luminaire on an individual frame basis, without affecting a slow acting color loop controlling the color temperature of the luminaire, the method comprising: receiving a reference value representative of a target color; receiving a luminance signal defining the luminance of the luminaire per frame; adjusting a modulated signal driving the luminaire directly responsive to the received luminance signal, thereby controlling the luminance of the luminaire per frame; sampling the optical output of the luminaire per frame; comparing a value responsive to the sampled optical output with a value responsive to the received reference value to output a difference signal; and further adjusting the modulated signal driving the luminaire responsive to the compared value so as to reduce the difference signal.

Abstract: A system for providing power over Ethernet comprising: a plurality of means for receiving a current limited power signal, each of the means receiving a unique current limited power signal; a plurality of means for connecting one end of a cable, the cable comprising a plurality of twisted wire pairs, each of the cables providing a data communication and power path to a particular node connecting jack; a plurality of connectors each for connecting one end of a patch cable, the plurality of connectors being each operatively connected by pairs of conductors to a unique one of the plurality of means for connecting one end of a cable to allow for data communication between the patch cables and the cables; and a plurality of means for injecting the received current limited power signal onto at least one of the pairs of conductors.

Abstract: A power over Ethernet controller comprising: a control circuitry; at least one powering port, each of the at least one powering port comprising a unique means for controlling a switch associated therewith; and at least one current limiter, each of the at least one current limiter being associated with a unique one of the at least one powering port, each of the at least one current limiter being operable to limit the current through the controlled switch to a particular one of a plurality of values, each of the values being in excess of 100 mA, the particular value being selected responsive to the control circuitry.

Abstract: A method of controlling the output of a luminaire by receiving a first target signal associated with a first frame; generating a first light output control signal for an on time portion of the first frame, the light output control signal responsive to the received first target signal; sampling a light output during the on time portion of the first frame, the light output being responsive to the first light output control signal; receiving a second target signal associated with a second frame, the second frame following the first frame; comparing the received second target signal with the sampled light output of the on time portion of the first frame; and generating an error signal responsive to the comparing.

Abstract: A redundant powering system for a powered device receiving power over communication cabling, the redundant powering system comprising: a redundant power supply comprising a first power sourcing equipment and a second power sourcing equipment; a powered device; communication cabling connecting the redundant power supply to the powered device, the communication cabling comprising a first path connecting the first power sourcing equipment to the powered device and a second path connecting the second power sourcing equipment to the powered device, the first and second paths at least partially being constituted of a single structured cable, the at least one powered device comprising at least one signature impedance, the redundant power supply being operable so that power is operably supplied to the powered device from only one of the first and second power sourcing equipment.

Abstract: A combiner for use with a powered device having high power needs, the combiner comprising: a first power input adapted to receive a first power signal over a first set of wire pairs utilized to carry communication data; a second power input adapted to receive a second power signal over a second set of wire pairs, wherein the first power signal is combined with the second power signal to produce a combined high power signal; and a control circuit operable to sense the combined high power signal and to supply the combined high power signal to a powered device in response to the sensed combined high power signal. Also disclosed is a local area network adapted to supply power to powered devices over a plurality of paths utilizing the combiner, the local area network thus supplying high power to a powered device.

Abstract: A system for placing and maintaining a computer in a standby mode during power failure, utilizing one of: a powered device controller exhibiting a maintain power signature functionality and arranged to receive power over communication cabling; and a MEMS flywheel energy system to provide a standby power. The standby power is less than the power required for full operation. In one embodiment the system additionally exhibits: a mains power failure sensor; a volatile memory arranged to be powered from the source of standby power in the event of a failure of mains power; and a processor operative responsive to the mains power failure sensor to store status information on the volatile memory and reduce power demand of the processor and associated devices to no more than that available from the source of standby power.

Abstract: An optical sampling and control element for use with a luminaire exhibiting a cycle and a frame, the optical sampling and control element being constituted of a color sensor in optical communication with the luminaire; and a sampler connected to the outputs of the color sensor, the sampler comprising an integrator arranged to integrate the outputs of the color sensor over a predetermined period less than the frame.

Abstract: A method of controlling the luminance of a luminaire on an individual frame basis, without affecting a slow acting color loop controlling the color temperature of the luminaire, the method comprising: receiving a reference value representative of a target color; receiving a luminance signal defining the luminance of the luminaire per frame; adjusting a modulated signal driving the luminaire directly responsive to the received luminance signal, thereby controlling the luminance of the luminaire per frame; sampling the optical output of the luminaire per frame; comparing a value responsive to the sampled optical output with a value responsive to the received reference value to output a difference signal; and further adjusting the modulated signal driving the luminaire responsive to the compared value so as to reduce the difference signal.

Abstract: A power over Ethernet controller supporting a plurality of powering modes, the power over Ethernet controller comprising: a pair of power sourcing equipments; and a control circuit; the control circuit being operative to control each of the pair of power sourcing equipment units in one of a first mode and a second mode, the first mode comprising operating the pair of power sourcing equipments as a single power sourcing equipment operable to power a single powered device over communication cabling, and the second mode comprising operating each of the power sourcing equipments of the pair independently so as to each be operable to power an associated powered device over communication cabling.

Abstract: A method for supplying power to a local area network node over communication cabling, the method comprising: injecting current-limited current into communication cabling connected to the local area network node; measuring a voltage developed in accordance with said injected current limited current across said communication cabling at three pre-determined intervals; and determining, as a consequence of said measured voltage at said three pre-determined intervals whether characteristics of the local area network node allow it to receive power over the communication cabling.

Abstract: A method of controlling the output of a luminaire by receiving a first target signal associated with a first frame; generating a first light output control signal for an on time portion of the first frame, the light output control signal responsive to the received first target signal; sampling a light output during the on time portion of the first frame, the light output being responsive to the first light output control signal; receiving a second target signal associated with a second frame, the second frame following the first frame; comparing the received second target signal with the sampled light output of the on time portion of the first frame; and generating an error signal responsive to the comparing.

Abstract: A power supply subsystem configured for connection between a LAN switch and at least one node, the power supply subsystem providing electrical power to the at least node over communication cabling, the power supply subsystem comprising: a management and control unit; at least one port for connection to a LAN switch; a combiner combining power into the communication cabling substantially without interfering with data communication between the LAN switch and the at least one node; and current limiting circuitry controlling current of the power delivered into the communication cabling via the combiner, wherein the management and control unit is operative to interrogate the at least one node to which it is intended to transmit power over the communication cabling in order to determine whether the node's characteristics allow it to receive power over the communication cabling.

Abstract: A system for rack level power management, the system comprising: at least one power source; a management module; and a plurality of power managed modules in communication with the management module and connected to draw power from the at least one power source, each of the plurality of power managed modules comprising a power manager and an operating circuit, the operating circuit being operable at a plurality of power drawing levels responsive to the power manager, the management module being operative to allocate a power budget to each of the plurality of power managed modules and communicate the allocated power budgets to the power managers, each of the power managers being operative to control the operating circuit of the power managed module to be operable at a power drawing level within the allocated budget.

Abstract: A backlighting system comprising: a controller; at least one luminaire comprising a plurality of LEDs; and at least one thermal sensor in communication with the controller, the controller being operative to control the luminance of the at least one luminaire responsive to the at least one thermal sensor. Preferably, the control of the luminance comprises: in the event that a temperature indication responsive to an output of the at least one thermal sensor is greater than a first pre-determined maximum, reducing the luminance of at least one of the at least one luminaire.