Power is fungible

Engineers tend to think of power as a resource independent of source, amps and volts routed through a circuit to perform work, unless the application brings with it a requirement for a specific kind of power. Designing power systems requires careful attention to device efficiencies and energy capacities. Unfortunately, that attention is sometimes wrongly focused on the source, instead of the management, of that power.

Recent advances have provided more flexibility to designers addressing demanding mobile power applications, using techniques from efficiency to alternate energy sources to parasitic energy capture to extend operating life.

For example, UltraCell (www.ultracell.com) recently announced that it has received the fuel cell industry’s first U.S. Army SAR, approving the company’s 25-W mobile fuel cell system (also available to OEMs) for field use. The XX25 can provide uninterrupted power for a 72-hour mission with a total weight of 8.8 lbs compared to 27 lbs of batteries.

Pulling in energy that would otherwise be wasted is a great approach, and energy harvesting modules from Advanced Linear Devices (www.aldinc.com) capture, accumulate and store power from a variety of alternative power sources for Bluetooth and other wireless sensor circuits operating in the 3 to 5-V range for intermittent duty cycle operations.

On another front, STMicroelectronics and CEA, a French public technological research organization have announced they will pursue advanced research in areas such as solid-state microbatteries and micro-fuel cells as well as other promising technologies such as thermoelectric and mechanical scavenging.