Electronic Design

Exciting New Directions In Power Brighten Economic Gloom

It never ceases to amaze how much mindbogglingly fascinating technology is associated with the supposedly staid discipline of power technology. Take gamma correction in TV receivers. The gist of it is simple.

Once you replace your compact fluorescent LCD screen backlighting with an array of LEDs, you can dynamically control the brightness across the screen to match the relative brightness of blocks of the video signal in real time. The effect improves the viewing experience on dramatically lighted scenes.

SUPERCAPS TO THE RESCUE • Then there’s Advanced Analogic Technology (AAT) and its latest supercapacitor developments (see “Chips Help Supercaps Flash White LEDs Brighter For Higher-Res Photos” at www.electronicdesign.com, ED Online 19559). The company now is adapting its LED flash supercap driver to a solid-state-drive (SSD) power-management unit (PMU).

By employing a DRAM front end, designers can overcome the limited number of read/write cycles that plague SSD flash. Otherwise, they would write to the DRAM instead of the flash most of the time. A backup system with a supercap thus powers the DRAM, and there would only be a write to the SSD at system turn-off or during a forced save.

If there’s a power failure, the supercap would have enough energy to guarantee the completion of the write cycle. This is an important application, says Richard Williams, president of AAT, though he’s dubious that the camera flash app by itself could drive the price of supercaps low enough to make them truly attractive in broad applications.

DOWN ON THE ENERGY FARM • My own favorite growth technology in the power arena involves energy harvesting (see the figure). It works synergistically with low-power wireless mesh networks to open up a galaxy of new applications (see “The Field Of Energy Harvesting Begins To Ripen,” ED Online 20222).

The general electronics industry is braced for a negative impact from today’s subprime market conditions, says the Darnell Group, a power-industry analysis company. Yet various energy-harvesting technologies, micro batteries, and related power-management ICs are poised for rapid and profitable growth in 2009, according to the company.

Several factors ranging from the commercial rollout of thin-film batteries from several companies to new government regulations and economic incentives are converging. This will produce a favorable environment for wireless sensor systems incorporating power sources based on energy harvesting, the Darnell Group concludes. In fact, many incentive programs are available worldwide to pay for the installation of wireless sensor and control networks.

The U.S. Energy Policy Act of 2005 (EPAct 2005) includes an “Energy-efficient Commercial Building Deduction.” It provides a tax deduction for commercial buildings that cut their annual energy and power consumption by 50% compared to the ASHRAE 2001 standard. Extended through Dec. 31, 2013, the deduction equals the cost of energy-efficient property installed during construction, with a maximum deduction of $1.80 per square foot of the building.

The Darnell Group also notes that emerging technologies struggle to gain a significant commercial foothold even in boom times, so a deep financial crisis isn’t likely to make their situation significantly worse. Today’s economic challenges could even make these products more attractive.

Energy-efficiency regulations and tax credits are making these systems more affordable, both at initial installation and over the lifetime of the system. Wireless approaches are generally less expensive than wired solutions. And if batteries no longer need replacing, they become more attractive.

Even my old boss, Cypress Semiconductor president and industry maverick T.J. Rogers, has the energy-harvesting bug. At an energy-focused press powwow with National Semiconductor’s Brian Halla and Actel’s John East in December, he showed off a Cypress-powered wireless-mesh industrial temperature controller. “This one’s battery-powered,” he said. But the RF in the next one will run off a turbine spun by the sensor’s own pneumatics.

TAGS: Components
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