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A new kind of power adapter is barely bigger than a plug.

By Kevin Bullis

A startup called FINsix has developed laptop power adapters that are 75 percent smaller than their conventional counterparts. The technology employed could also be used to improve the efficiency of a wide variety of devices and appliances, including washing machines and air conditioners.

FINsix’s first product, which the company will unveil next month at the Consumer Electronics Show in Las Vegas, replaces a conventional charging brick with a device just a little bigger than an ordinary plug. The 65-watt power adapter—which delivers more power than many laptops use—can charge multiple devices at once. It will be available by the middle of next year.

The power adapter is the first commercial application of a novel circuit design developed byDavid Perreault, a professor of electrical engineering and computer science at MIT (see “Power Electronics to Improve Computer Efficiency” and “Efficiency Breakthrough Promises Smartphones That Use Half the Power”).

FINsix’s power adapter is an after-market charger that can work with a variety of laptops and other devices. The company is also working with a laptop manufacturer to produce a dedicated charger. The power adapter has the potential to be far cheaper than conventional ones, because it’s smaller, it’s simpler to manufacture, and it uses far less material.

In addition to shrinking power adapters, the new circuit design could reduce the size and cost of a variety of devices known collectively as power electronics. These devices manipulate electricity, changing properties such as voltage and converting between AC and DC power; they can precisely control the power that goes to electric motors and compressors. Better power electronics can improve the efficiency of, say, household air conditioners, but they typically aren’t used in such applications because of their high cost.

FINsix’s technology shrinks power electronics by increasing the frequency at which these devices operate. The higher the frequency, the smaller the device can be. But ordinarily, higher frequencies also reduce efficiency.

The researchers at MIT and FINsix developed a way to recycle much of the energy that’s normally lost inside a power adapter, improving efficiency and making it practical to use frequencies 1,000 times higher than those used in conventional power adapters. “The rest of the field is making incremental changes and getting diminishing returns,” says Charles Sullivan, a professor of engineering at Dartmouth, who is not involved with the company. But FINsix, he says, is “leaping past that barrier.”

Other academic researchers and companies are working to shrink the size of power electronics by turning to new materials, such as gallium nitride, that can operate more efficiently at high frequencies than the silicon semiconductor materials used now (see “Eliminating the Laptop Charging Brick”). But the new materials can be expensive and are limited to specialty applications. As these materials get cheaper and are more widely adopted, FINsix’s technology could be used in conjunction with them to make power electronics even smaller and more efficient.