Driver failures may represent more than half of the failures of LED luminaires, especially for higher outputs. Further, a single constant-current driver cannot regulate current throughout parallel columns of LEDs. A solution to these problems is presented using contra-connected pairs of LEDs or "couplets" which can be efficiently driven with AC power. Couplets can be further assembled into "reactive strings" where reactive elements (capacitors or inductors) are distributed throughout the string. Reactive strings can be driven as part of resonant tank circuits where damping is provided by the LEDs and resonance regulated the power. Near-lossless reactances control power both globally and locally. Resonance provides a passive power control mechanism that requires no active components. The distributed reactive elements allow power in each couplet to be independently regulated.
This event is co-sponsored by the Stanford SystemX Alliance and the IEEE SCV PES/IAS Chapter.