Abstract:
A ring balancer comprising a plurality of balancing transformers facilitates current sharing in a multi-lamp backlight system. The balancing transformers have respective primary windings separately coupled in series with designated lamps and have respective secondary windings coupled together in a closed loop. The secondary windings conduct a common current and the respective primary windings conduct proportional currents to balance currents among the lamps. The ring balancer facilitates automatic lamp striking and the lamps can be advantageously driven by a common voltage source.
Abstract:
A backlighting arrangement constituted of a driving transformer arrangement; a plurality of lamp pairs, each of the constituent lamps of the plurality of lamp pairs exhibiting a first electrical connection and a second electrical connection; and a plurality of balancing transformers, each comprising a primary winding and a secondary winding magnetically coupled to the primary winding, and each associated with a particular one of the plurality of lamp pairs, the primary winding of each of the plurality of balancing transformers serially connected between the second electrical connections of the constituent lamps of the associated lamp pair, the secondary windings of the plurality of balancing transformers serially connected in phase, with a first end of the serially connected secondary windings of the balancing transformers connected to one phase output of the driving transformer arrangement.
Abstract:
A ring balancer comprising a plurality of balancing transformers facilitates current sharing in a multi-lamp backlight system. The balancing transformers have respective primary windings separately coupled in series with designated lamps and have respective secondary windings coupled together in a closed loop. The secondary windings conduct a common current and the respective primary windings conduct proportional currents to balance currents among the lamps. The ring balancer facilitates automatic lamp striking and the lamps can be advantageously driven by a common voltage source.
Abstract:
An apparatus and method for driving a lamp are provided. In one embodiment, an inverter having four switching elements is split into two inverter arms that are deployed at separate terminals of a floating lamp structure to achieve even light output. A controller drives both inverter arms such that power switching lines do not cross the floating lamp structure. In one embodiment, the controller adjusts the brightness of the lamp structure by adjusting the phase difference between outputs of a first inverter arm relative to a second inverter arm. In one embodiment, the controller adjusts the brightness by symmetrically pulse width modulating the outputs of the first inverter arm and the second inverter arm.
Abstract:
A ring balancer comprising a plurality of balancing transformers facilitates current sharing in a multi-lamp backlight system. The balancing transformers have respective primary windings separately coupled in series with designated lamps and have respective secondary windings coupled together in a closed loop. The secondary windings conduct a common current and the respective primary windings conduct proportional currents to balance currents among the lamps. The ring balancer facilitates automatic lamp striking and the lamps can be advantageously driven by a common voltage source.
Abstract:
A ring balancer comprising a plurality of balancing transformers facilitates current sharing in a multi-lamp backlight system. The balancing transformers have respective primary windings separately coupled in series with designated lamps and have respective secondary windings coupled together in a closed loop. The secondary windings conduct a common current and the respective primary windings conduct proportional currents to balance currents among the lamps. The ring balancer facilitates automatic lamp striking and the lamps can be advantageously driven by a common voltage source.
Abstract:
A solid state lighting driver arrangement exhibiting a plurality of LED strings receiving power from a single power source, the single power source providing a discontinuous current, wherein a plurality of first windings are provided, each associated with a particular LED string and coupled to provide current balancing between the various LED strings. The discontinuous current resets the windings during the off time or during a reversal period. In one particular embodiment, a second winding is magnetically coupled to each of the first windings, and the second windings are connected in a closed in-phase loop. In another particular embodiment, at least two of the first windings are magnetically coupled to each other, thus ensuring a balance between current in each LED string.
Abstract:
A driving arrangement for light emitting diode (LED) based illumination constituted of: a comparison circuitry arranged to compare an integral of a target current over a target illumination time for at least one LED based luminaire with an integral of an illumination current over an illumination time for the at least one LED based luminaire, the comparison circuitry arranged to output a comparison signal; and a control circuitry in communication with the comparison circuitry and arranged to alternately: allow the flow of electrical current through the at least one LED based luminaire responsive to a first condition of the comparison signal; and prevent the flow of electrical current through the at least one LED based luminaire responsive to a second condition of the comparison signal, the second condition different from the first condition.
Abstract:
A backlighting arrangement constituted of: a means for receiving an alternating current comprising a first lead and a second lead; at least one luminaire; and at least one first balancing transformer pair each associated with a particular one of the at least one luminaire, the primary of a first balancing transformer of the first balancing transformer pair serially coupled between the first lead of the means for receiving an alternating current and a first end of each of the at least one luminaire, and the primary of a second balancing transformer of the first balancing transformer pair serially coupled between the second lead of the means for receiving an alternating current and a second end of each of the at least one luminaire. The secondaries of all of the at least one first balancing transformer pair are serially connected in a closed in-phase loop.
Abstract:
An apparatus and method for driving a lamp are provided. In one embodiment, an inverter having four switching elements is split into two inverter arms that are deployed at separate terminals of a floating lamp structure to achieve even light output. A controller drives both inverter arms such that power switching lines do not cross the floating lamp structure. In one embodiment, the controller adjusts the brightness of the lamp structure by adjusting the phase difference between outputs of a first inverter arm relative to a second inverter arm. In one embodiment, the controller adjusts the brightness by symmetrically pulse width modulating the outputs of the first inverter arm and the second inverter arm.