LEDs are rapidly taking over areas traditionally served by incandescent and fluorescent lights. And there's even brighter technology in the wings.
Your name up in LEDs
Well, it could happen if you were playing at the Bardavon Theater in Poughkeepsie, N.Y. The entertainment complex hosted many noted artists over its 130-year history including Mark Twain, the Barrymores, George M. Cohan, Frank Sinatra, and Martha Graham. Now, it's hosting a relamped marquee replacing its original 3,600 incandescent bulbs with energy-efficient LED bulbs from Ledtronics Inc. of Torrance, Calif. Results of the switch to LEDs include improved aesthetics, reduced maintenance, and energy efficiency.
The Bardavon opened in 1869 as the Colllingwood Opera House presenting live performances. As vaudeville waned, the theater converted to a premier movie theater where first-run silent and then talking pictures played. Slated for demolition in 1975, a nonprofit group rescued the historic theater from the wrecking ball and started restoring the theater. As part of the restoration, the 1940-style three-sided marquee and blade sign were replaced with replicas. The replica marquee and blade were exact copies, right down to the original incandescent lamps and chaser circuitry. The use of chasers prevents every light from operating at the same time. If they did, the sign would draw an impressive 38 kW of power.
But sign maintenance was a headache. Operationally, the sign ran up to 8 hr per show about 150 nights of the year. That's an average of 900 to 1,200 hr of operation annually. The incandescent bulbs only lasted about 1,000 hr because the on-off chaser circuits created thermal stresses on the bulb filaments. This means, on average, every bulb in the sign would be gone in a year. Someone on a ladder could handle lamps in the marquee, but the top of the 50-ft blade sign is accessible only with a boom lift.
A grant from the New York State Energy Research & Development Dept. let the Bardavon marquee and blade sign switch to LED-sourced lighting. The LED lamps came packaged in sealed polycarbonate globes resembling the original incandescent lamps. The globes protect the LED emitters and associated electronics from water and seasonal weather damage as well as from the deteriorating effects of UV rays. The LED lamps even screw into the same 25-mm Edison socket used by the original lamps.
The change in power demand was noteworthy. The new LED lamps draw only 4,680 W, about one-eighth the power of the incandescent lamps. There was maintenance relief as well. The average LED lamp lasts 50,000 to 100,000 hr. So it should be 50 years before any bulb needs replacing. Each lamp assembly contains a cluster of LEDs; so even if one emitter should fail, the others still give off light. The electronic circuitry in each bulb handles the on-off cycles of the chasers perfectly without the thermal stress on filaments associated with incandescent lamps.