The secret is a tiny radio-frequency generator in each bulb, transmitting energy to a surrounding cloud of mercury gas and in turn to the fluorescent coating (diagram). The principle is not new; the breakthrough lies in shielding the bulb to avoid interference with other electronic devices, especially televisions and radios. Since any ordinary substance that blocks radio waves would also be opaque to light, the solution must be ingenious. Unfortunately, Intersource Technologies, which developed the bulb with backing from Ohio-based American Electric Power Co., the nation’s second largest utility, isn’t saying how it’s done.
This ingenuity comes at a price. Like compact fluorescents, E-Lamps should cost around $15 per bulb at first, less as they go into mass marketing. But counting the cost of the bulb and the electricity to run it, a 25-watt E-Lamp should save around 20 cents a week compared with a 100-watt incandescent, and give the same amount of light. There are some 1.5 billion light sockets in the United States; each incandescent that is replaced by an E-Lamp would save an estimated ton of carbon dioxide from electrical generating stations over the life of the bulb, a small step toward reducing emissions of greenhouse gases.
As for the high price, Intersource chairman Pierre Villere expects consumers will treat the bulb as a durable good. Eventually, he predicts, it will take its place “next to the hair dryer, the microwave and the food processor” as an indispensable convenience. Since the electronic components last indefinitely, the bulb should fail only when the phosphor deteriorates (or someone knocks the lamp off the table). And instead of burning out with a “pop,” the new bulbs will gradually become less bright. Someday lamps and fixtures may have the electronic components built into their base, and consumers will just slip on a cheap, replaceable glass jacket containing the mercury and phosphor. Then we will truly have come a long way from the candle. As Villere puts it: “It’s almost inconceivable that an invention that is so much a part of our lives as the light bulb has been around since Edison with so little innovation.”
Inside the Radio-Wave Bulb 1. An electric oscillator linked to a small, coiled antenna produces radio waves much like a radio station does. 2. Electrons n atoms of mercury vapor absorb the radio waves, which excite the electrons to a higher “energy state.” 3. The electrons emit photons, or packets, of invisible ultraviolet light. 4. A phosphor coating on the inside of the bulb absorbs the ultraviolet light, exciting electrons, which then emit visible light.
