By John Keller
The growing use in aerospace and defense electronic systems of smart power management -- or digital monitoring, control, and communications in power supplies -- is enhancing the efforts of electronic systems designers not only to enhance power system health monitoring, but also is helping them push the bounds of power capacity and device efficiency, and shrink the size and weight of power-management devices.
Power electronics manufacturers today can take advantage of powerful and commercially available digital microprocessors to handle automatic power monitoring, control, and communications far more easily and efficiently than they could years ago when automated power control required the use of complex and expensive application-specific integrated circuits (ASICs), explains Martin Schlecht, president and chief executive officer of SynQor Inc. in Boxborough, Mass.
"The digital power processor gave us the reality of an ASIC, but in less space and far fewer components, and we also no longer pay the price of customization," Schlecht says. With that readily available digital control for smart power electronics, power supply designers can enhance the capabilities of the power sections of their devices without adding size and weight.
"By devoting less room to the control circuit, more room can be devoted to the power circuit," Schlecht continues. "This helps us process more power, or process the same amount of power more efficiently. What digital control gives us is the ability to move toward smaller devices at lower power."
Increasing the efficiency in power management, as well as shrinking the sizes of power supplies and other power-management devices, are among the biggest pushes today in power management design, says Kai Johnstad, senior product marketing manager for defense, aerospace, and transportation products at Vicor Corp. in Andover, Mass.
"The big push in efficiency is in trying to get smaller and smaller power supplies, but with the power that users need," Johnstad says. "Smart power enables designers to maximize efficiency, and gives them greater ability to control the power system."
While digital interfaces in power devices have been available in one form or another for many years, today's power electronics often have the ability to monitor currents, voltages, temperatures, and outputs, and then report back to a system computer, points out Mike Innab, president of North American operations at Martek Power Abbott in Torrance, Calif.
"Digital control can let the computer know how the power supply is, and to make sure everything is okay, and to help determine if a failure is about to happen," Innab says. "If a thermal shutdown is about to happen, we can give a warning at five to ten degrees before shutdown occurs.
"With digital control, every single output is monitored," Innab continues. "In a critical application, the system monitor can see where it might be getting into trouble, before they actually get into trouble; with these new systems, they often can see it coming."
Digital control and communications also enables very fine changes in current to keep power within the bounds of sensitive equipment. "Smart power can sense voltage and raise or lower it to correct for errors," says SynQor's Schlecht. "That has to be quite fast. You have to do it in microseconds, which was too fast for microprocessors to that before now, but these new processors really are developed with circuitry to do these kinds of calculations very quickly."
One concern involves the military's typical need for sophisticated smart power technology. A quick power industry consensus is that military applications rarely need the most advanced smart power, except in specific applications like battery charging and system debugging.
"As far as the military goes, there are not that many advantages I see with digital control, except where the system is able to communicate with the power supply," Innab says. "One area I do see for smart power is battery chargers, where the algorithms to charge the batteries are quite complex. You can get more life out of batteries with smart power."
In these days of tight military budgets, defense systems designers also are concerned with system upgrades and technology insertion, in which smart power often is not a high priority. "There is a lot of retrofitting older vehicles and older airframes, and smart power is not as needed in those applications," says Vicor's Johnstad.
Absopulse Electronics Ltd.; Ottawa, Ontario; 613-836-3511; www.absopulse.com
Aeroflex Inc.; Plainview , N.Y.; 516-694-6700; www.aeroflex.com
AJ's Power Source Inc.; Land O Lakes, Fla.; 813-996-2583; www.ajpower.com
Analytic Systems; Delta, British Columbia; 604-496-9981; http://analyticsystems.com
Astrodyne Inc.; Mansfield, Mass.; 08-964-6300; www.astrodyne.com
Behlman Electronics Inc.; Hauppauge, N.Y.; 631-435-0410; www.behlmanpower.com
Comdel Inc.; Gloucester, Mass.; 978-282-0620; www.comdel.com
CUI Inc.; Tualatin, Ore.; 503-612-2300; www.cui.com
DRS Pivotal Power; Bedford, Nova Scotia; 902-835-7268; www.drspowersolutions.com
Electromech Inc.; Ramsey, N.J.; 201-934-3456; http://electromechinc.com
Energy Technologies Inc.; Mansfield, Ohio; 419-522-4444; www.ruggedsystems.com
Falcon Electric Inc.; Irwindale, Calif.; 626-962-7770; www.falconups.com
Gaia Converter Inc.; Saint Laurent, Quebec; 514-333-3169; www.gaia-converter.ca
HiTek Power Ltd.; Littlehampton, England; 011-44-1903-712400; www.hitekpower.com
International Rectifier; El Segundo, Calif.; 310-726-8000; www.irf.com
Interpoint, a Crane Co.; Redmond, Wash.; 425-882-3100; www.interpoint.com
ITT Power Solutions; West Springfield, Mass.; 413-263-6200; www.ittpowersolutions.com
Kepco Inc.; Flushing, N.Y.; 718-461-7000; www.kepcopower.com
Martek Power Abbott; Torance, Calif.; 310-202-8820; www.martekpower.com
MS Kennedy Corp.; Liverpool, N.Y.; 315-701-6751; www.mskennedy.com
National Hybrid Inc.; Ronkonkoma, N.Y.; 631-981-2400; www.nationalhybrid.com
North Atlantic Industries; Bohemia, N.Y.; 631-567-1100; www.naii.com
Pduke Technology Inc.; Walnut, Calif.; 909-598-5000; www.pduke.com
Pico Electronics Inc.; Pelham, N.Y.; 914-738-1400 ; www.picoelectronics.com
Pioneer Magnetics; Santa Monica, Calif.; 310-829-6751; www.pioneermag.com
Power Solutions Inc.; Titusville, Fla.; 516-484-6689; www.powersolutions.com
Powerstax plc; Farnborough, England; +44 (0) 1252 407800,; www.powerstaxplc.com
Rantec Power Systems; Los Osos, Calif.; 805-596-6000 ; www.rantec.com
Schaefer Inc.; Ashland, Mass.; 508-881-7330; www.schaeferpower.com
Solitron Devices Inc.; West Palm Beach, Fla.; 561-848-4311; www.solitrondevices.com
SynQor; Boxborough, Mass.; 978-849-0600; www.synqor.com
TDK-Lambda; Neptune, N.J.; 732-922 9300; http://us.tdk-lambda.com/hp/
Teledyne Microelectronics; Los Angeles, Calif.; 310-822-8229; www.teledynemicro.com
Tracewell Systems; Westerville, Ohio; 614-846-6175; www.tracewellsystems.com
Transistor Devices Inc. (TDI Power); Hackettstown, N.J.; 908-850-5088; http://tdipower.com/
UltraVolt Inc.; Ronkonkoma, N.Y. ; 631-471-4444; www.ultravolt.com
Vicor Corp.; Andover, Mass.; 800-735-6200; www.vicr.com
Vishay Intertechnology Inc.; Malvern, Pa.; 610-644-1300; www.vishay.com
VPT Inc.; Blacksburg, Va.; 540-552-5000; www.vpt-inc.com
XP Power; Sunnyvale, Calif.; 408-732-7777; www.xppower.com