Imagine a chip that uses as little as one-fifth the energy of conventional models. The secret is in recycling the energy from the chip's "clock," the timing signal normally used to synchronize computing functions, say scientists at the University of Southern California. The experimental chip, called the AC-1, has two different clock circuits. It can work with an ordinary clock mechanism-or a flip of a switch recycles the energy of the clock's electric signals to power the data-processing sections of the chip. The savings range from 75% to 80%, depending on how fast the clock is set to run (slower clock settings yield greater energy savings). Yet in its energy-recycling mode, the chip is able to perform the very same computing tasks it performed using the conventional clock circuit, say researchers. "Everything else about the chip's use can stay the same," says William Athas, project leader. "The application could be a portable computer, a digital watch, a cell phone, or a GPS position finder. The only difference would be that the batteries would last much longer." Now under way is a new design that will use power even more parsimoniously-consuming only one-tenth the power of conventional chips. On August 20, an account of the theory and testing will be presented at the International Symposium on Low Power Electronics and Design in Monterey, Calif. The chip designers: research professor Athas, graduate student Nestoras Tzartzanis, and research scientist Lars Svensson of the USC School of Engineering's Information Sciences Institute, Los Angeles.