Abstract: This invention discloses a local area network including a hub, a plurality of nodes, communication cabling connecting the plurality of nodes to the hub for providing data communication, and a power supply distributor operative to provide at least some operating power to at least some of the plurality of nodes via the communication cabling.

Abstract: This invention discloses a local area network including a hub, a plurality of nodes, communication cabling connecting the plurality of nodes to the hub for providing data communication, and a power supply distributor operative to provide at least some operating power to at least some of the plurality of nodes via the communication cabling.

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 power supply subsystem for providing electrical power to a local area network node over communication cabling, the power supply subsystem containing: a power management and control unit; programmable current limiting circuitry responsive to the power management and control unit to provide a programmable current limited output; voltage measurement means; and at least one of a combiner and a power supply interface operative to couple the programmable current limited output to the communication cabling. The power management and control unit is operative to: measure, utilizing the voltage measuring means at a plurality of pre-determined intervals, a voltage developed in accordance with the coupled programmable current limited output; and determine, as a consequence of the measured voltage whether characteristics of the node allow it to receive power over the communication cabling.

Abstract: Power sourcing equipment providing a plurality of power sources for connection over communication cabling to a single powered device, the power sourcing equipment comprising: a first power source; a second power source; a control circuit; a current sensor adapted to monitor an output current of the first power source, the current sensor being operatively connected to the control circuit; and a voltage regulating means associated with one of the first power source and the second power source, the voltage regulating means being responsive to the control circuit, the control circuit being operative responsive to the monitored output current to operate the voltage regulating means so as to maintain the monitored output current within a pre-determined range.

Abstract: A method for preventing an excess voltage from appearing at an output of a power over Ethernet controller, the method comprising: sensing that a powered device has been disconnected from a port; enabling a bypass path around a means for unidirectional current flow operatively connected to the port; and disconnecting power to the port responsive to the sensed disconnect, whereby the bypass path enables a discharge path for an output capacitor present across the port. The invention also provides for a circuit having a bypass path around a means for unidirectional current flow, the bypass path being enabled by a control circuit to prevent an excess voltage from appearing at a sensing input of the control circuit. In an exemplary embodiment the bypass path is enabled approximately simultaneously with disconnecting power from the output port.

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 system for powering and controlling an LED backlight, the system comprising: a control circuitry; a controllable power source responsive to the control circuitry; and a plurality of LED strings receiving power from the controllable power source, the control circuitry being operative to control the output voltage of the controllable power source responsive to a function of an electrical characteristic of at least one of the plurality of LED strings.

Abstract: A method of power management for use in a local area network, in which a plurality of local area network nodes are supplied power over communication cabling, the method comprising: supplying power to the plurality of local area network nodes over communication cabling; inputting total power availability; monitoring total power consumption; establishing a first limit for the monitored total power consumption; establishing a second limit for the monitored total power consumption, the second limit being lower than the first limit; in the event the first limit is exceeded, disconnecting the supplied power to at least one of the plurality of local area network nodes; and in the event the second limit is exceeded, supplying power to an additional node only after disconnecting the supplied power to at least one of the plurality of local area network nodes.

Abstract: This invention discloses a local area network including a hub, a plurality of nodes, communication cabling connecting the plurality of nodes to the hub for providing data communication, and a power supply distributor operative to provide at least some operating power to at least some of the plurality of nodes via the communication cabling.

Abstract: A secondary side post regulator arrangement for a plurality of LED strings. For each secondary winding, a first electronically controlled switch is provided arranged to control the power output, and a LED string is connected thereto. A second electronically controlled switch is further connected in series with the LED string, arranged to receive a PWM signal, thereby pulsing current through the LED string. A current sensing element is further provided outputting a voltage representation of the current through the LED string, and a synchronized sampling circuit is provided arranged to sample the voltage representation during the on period of the second electronically controlled switch. The sampled and held voltage representation is compared with a reference signal and fed back to control the first electronically controlled switch. The voltage output associated with each secondary winding is controlled, responsive to the reference voltage.

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 power control subsystem for controlling the supply of power transmitted to at least one node over communication cabling, the power control subsystem comprising: a plurality of references; a plurality of comparators, each of the comparators being associated with a particular one of the plurality of references; and a current limiter in communication with the plurality of comparators and arranged to limit current of the power transmitted over communication cabling responsive to the plurality of comparators.

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 communication network utilizing Power Over Ethernet technology including Power Sourcing Equipment (PSE) that includes a multi-purpose device that operates as a current sensing resistor under normal electrical operating conditions and operates as a protection device, e.g., a fuse, under fault conditions, such as, an internal switch failure and an overload occurring simultaneously.

Abstract: A system for supplying additional power to a module having an internal power supply, the system comprising: a module having an associated power supply, the power supply not being designed to accommodate power sharing; at least one load associated with the module, the load receiving power from the power supply; a variable current limited power source connected to the module supplying additional power to the at least one load; and a controller; whereby the variable current limited power supply is responsive to an output of the controller to vary the current limit of the variable current limited power supply.

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 system for backing up a computer in the event of a mains power failure, the system comprising: sensing means operative to sense a failure of mains power; means for receiving power over data communication cabling; a volatile memory; means for feeding power from the means for receiving power to the volatile memory; and an interrupt generating means for generating an interrupt to a processor responsive to the sensing means, the processor being operative responsive to the generated interrupt to store status information on the volatile memory.

Abstract: A system for placing and maintaining a computer in a standby mode during power failure, the system comprising: a mains power failure sensor; a source of standby power, the source of standby power being less than the power available for full operation; 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. In an exemplary embodiment the source of standby power is one of a battery, a capacitor, a flywheel energy storage system and a power over Ethernet connection.

Abstract: An interchangeable power over Ethernet module having a plurality of configurations, and a single unified pin out, the power over Ethernet module comprising: at least one circuitry managing the supply of power over Ethernet to at least one port; a first set of connections associated with a first one of the plurality of configurations, the first one of the plurality of configuration comprising supervisory control circuitry, the first set of connections being operably connected to the supervisory control circuitry; the first set of connections being connected together in a second one of the plurality of configurations.