the sun is not enough
TRANSCRIPT
REVIEW
The Sun is Not Enough
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You paid $23 for a nightlight?,” mywife asked accusingly. I could notdeny it; the evidence was in my
hand, but I insisted that dubbing theLightSprite a nightlight would be likecalling a clarinet a noisemaker. Then, forgood measure, I appealed at length toher curiosity, focusing on gallium nitridesemiconductors. (This tactic might notwork with all spouses, but mine teacheshigh-school science.)
LEDs and lasers that emit gorgeousblues, greens, or violets are one of thegreat recent success stories in electro-optics, I lectured. The GaN diodes wereinvented by the legendary Shuji Nakamu-ra at Japan’s Nichia Corp. in the 1990s andhave been available commercially for anumber of years. They’re already com-mon in green traffic lights, but only in thepast year or so have they shown up in toys.
Some of the results have been quitedazzling. The tennis-ball–sized Light-Sprite, from Color Kinetics, belongs to a new line of lights,called Sauce, that includes both plug-in and battery-poweredversions. My wife’s skepticism evaporated immediately whenI plugged in the little unit. Even I was pleasantly surprised asintense, bright, saturated hues swam across its little, half-moon-shaped, translucent surface. If the flower children hadhad these things in Haight Ashbury, back in the late 1960s,
there’s no telling what heights of cosmicconsciousness they could have attained.
Most of the Sauce lights have fourmodes, controlled by pushing a littlebutton under the screen. In one mode,waves of intense color, one afteranother, sweep across the light’s sur-face. In another, the light jumps sud-denly and randomly from one color toanother. The light may also be set tocontinuously display a single hue, froma palette that would have pleased theRussian painter Wassily Kandinsky [seephoto]. Colors are chosen by turning adial underneath the button. A fourthmode enables the brightness to be setwith the dial.
As you might have guessed, thelights work by electronically controllingthe output of three LEDs: a blue GaNone, a green GaN one, and a red alu-minum gallium indium phosphide one.Packaging for the particularly bright
LightSprite encourages buyers to “add instant mood to bed-rooms…or wherever you like.” Who would have thought thatcompound semiconductors could be so atmospheric?
Contact: Color Kinetics Inc., 10 Milk St., Suite 1100, Boston,MA 02108; +1 617 423 9999; fax, +1 617 423 9998; e-mail,[email protected]; or Web, http://www.cksauce.com/.
—Glenn Zorpette
R E S O U R C E S
TOOLS &TOYSREVIEW
Over the Solid-State Rainbow
The squat silver object on my officewindow elicited two questionsfrom colleagues: “What is it?” and
“Does it work?”Answering the first question was easy:
an iSun solar charger from ICP Global
Technologies that can be used to chargesmall electronic devices needing less than2 W. The answer to the second query
depends to a certain extent on your rela-tionship with the Great Outdoors.
The green LED indicator that lightsup when the unit is working, never litup, and I deduced that the glare-reduc-ing film on the office windows had ren-dered the iSun impotent, in spite of the14 percent efficiency of its crystalline sil-icon solar cells. I would have to take it
home to test it, but first I bought a carcigarette lighter adapter so I could usethe iSun to charge the battery in my cell-phone—a Samsung SCH-3500.
In my apartment, I stuck the solarcharger to the same clear windowthrough which the sun bathes my boda-cious jade plant with abundant after-noon light.
The iSun’s clamshell casing unfoldsto the dimensions of 18.4 by 11.1 by3.2 cm high to reveal two solar cell pan-els. It has a male connector for female
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LightSprite, a nightlight from Color
Kinetics, uses gallium nitride LEDs to
produce intense colors, as shown above.
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plugs and a female port for male plugs,connector and port being located onopposite ends of the hinge. The iSuncomes with two suction cups, for stick-ing the unit on a window; a femalesocket adapter cable, for use with carcigarette lighter adapters; and two maleand four female adapters to connect thecharger to various devices (though noneof them worked for any of my electronicdevices). A switch on the clamshellallows toggling between 6-V and 12-V outputs and the company says theproduct can be used to charge therechargeable batteries in video gameconsoles, small radios, GPS re-ceivers, MP3 players, digital cam-eras, and even laptops.
The unit can be daisy-chainedwith up to five more iSuns to in-crease power output; alone it shouldhave been more than enough tocharge my cellphone. I plugged thephone into the cigarette lighteradapter, and plugged that into thefemale socket adapter, and the lastinto the iSun that was stuck to myapartment window.
Days passed, many of themcloudy. My cellphone was dead.
Whenever I gave in and chargedthe phone in its normal charger, Iretrieved angry voice mail messages chas-tising me for never answering my phone.
Finally a bright sunny day, and after a lit-tle over six hours, the battery was two-thirdscharged. But the iSun box said it wouldtake only three hours for a full charge.
I sent an e-mail to ICP Global Tech-nologies for help. “Why is the recharger tak-ing so long to charge my cellphone bat-tery?” I asked. The prompt customerservice reply informed me that if the iSunis “behind a window,” it is not getting themost direct sunlight and it will thereforetake longer to charge than if placed outside.
Further, my particular cellphone bat-tery’s capacity is 1000 mAh. At the sug-gested 6-V setting, “the maximum out-put of the iSun is 290 mA. If you aremounting the iSun on a window, you arenot getting the most direct sunlight,” theservice rep said in an e-mail. “If the iSunis charging at 100 mA (this is just anestimation as I do not know how theiSun was placed), it would take about
10 hours of sunlight for a completecharge (1000 mAh/100 mA = 10 hours).It would thus seem reasonable that itwould take about six hours for a two-thirdscharge,” concluded customer service.
While the iSun box shows a mancharging his cellphone by attaching thedevice to a train window [see photo], thecustomer service representative’s com-ments contradicted this image of “free”power anytime, anywhere: if time is an
issue, and with me it is, the iSun shouldbe used outside in direct sunlight.
After reading the e-mail, I strokedmy beard in contemplation of my lim-ited options. I could risk almost certaininjury by trying to stick the iSun on theoutside of my third-story window. Icould risk almost certain theft by settingthe iSun and cellphone on the stoop ofmy Brooklyn apartment building.
I could go camping, but the best placesto camp are often out of cellphone range.Perhaps I could pitch a tent in CentralPark for a few hours, long enough tocharge my phone so I could use it to callmy wife for bail money after the policearrest me for illegally camping in the park. IC
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What about trying the charger out onother electronic devices, like my PDA?No, my Palm IIIx runs on two AAA bat-teries. My portable CD player? Unfortu-nately, it, too, runs on regular batteries.
Maybe I could charge my beard trimmer?
Nope. The iSun doesn’t have anadapter for the type of standing chargermy beard trimmer uses.
Perhaps true outdoors enthusiastswill benefit from the $79.99 iSun. But
denizens of the concrete-and-glass jun-gle might be better off spending that $80on an extra phone battery or several zinc-air fuel-cell batteries [see “Power to thePhones,” IEEE Spectrum, August 2001,pp. 68–69], real insurance for those drabdays when the sun doesn’t shine, yourbatteries are dead, and there’s no payphone in sight.
Contact: ICP Global Technologies,6995 Jeanne Mance St., Montreal, QCH3N 1W5, Canada; toll-free only inNorth America, +1 888 427 7652; e-mail,[email protected]; or Web,http://www.icpglobal.com.
—Harry Goldstein
Elizabeth A. Bretz, Editor
The iSun solar charger is best used outdoors in full sunlight. The businessman
[inset] had better have a long train ride and be sitting on the sunny side of the
train if he hopes to charge his portable electronic devices through the window.