Cranking Up the Juice in Your Car
Heated seats. VCR and TV for the kids. Powerful stereo. Cellular phone. How about a toaster?
As the list of electronic gizmos in new cars continues to grow, so does the drain on the car's electrical system. Standardized decades ago when headlights and a cigarette lighter were the height of car-tech, car alternators still crank out 14 volts today. But with cars becoming more and more like audio-visual centers on wheels, auto makers have been looking for a way to pump up the juice.
Now, work at the Massachusetts Institute of Technology has resulted in a plan to upgrade automotive electrical systems to 42 volts. The changeover should be fairly painless, since it can be integrated easily and cheaply into the existing manufacturing process, says the project's lead scientist, David J. Perreault.
Much of the low-cost improvement that Perreault's team accomplished comes from a redesign of the alternator. The scientists replaced three passive elements that direct current with active switches. This yields more ways to control power and optimize the current flow. The change resulted in surprising fuel savings, too. Perreault expects to see the 42-volt system in cars within five years.By Petti Fong