Close Advertisement

TECH RECON

Power Supplies Evolve to Meet Needs of Boards and Systems

As military embedded systems get more complex and powerful, the importance of proper power system design only grows. Power supply and power conversion vendors are keeping pace with new innovative technologies.

JEFF CHILD, EDITOR-IN-CHIEF

Keywords in this Article:

No Keywords

  • Page 1 of 1
    Bookmark and Share

Article Media

Gone are the days when military system designers could afford to treat choosing power supplies and power conversion electronics as an afterthought. With more and more computing stuffed into smaller spaces, power has direct implications on the size, cooling and mobility of a board- or box-level system. Add to that the challenges of multi-voltage electronics and the complexity of distributed system architectures, and it’s clear that military system designers need solutions that address those needs. Often the unsung hero of a military system design, power supplies and converters are critical enablers for meeting today’s rugged requirements.

Vendors are smoothing the way with flexible options and robust solutions. The good news is that military power conversion vendors are easing the burden with more efficient products, new partitioning strategies and increased ruggedization. New solutions continue to roll out, not just at the component or brick level, but also at the module and board level. Meanwhile, uninterruptible power supplies (UPS) are now more critical than ever as computer and network gear pervade the battlefield.

Designed for Military Use

Exemplifying state-of-the-art power supplies, Vicor last summer introduced its new Westcor MicroPAC power factor corrected AC/DC power system providing up to 1300W of continuous power at up to 92% efficiency and 25 Win3 power density in a compact 4 x 1.72 x 7.45 inch package. Offering semi-regulated output voltages of 12, 24, 36 and 48 VDC via four factory-configurable isolated outputs, the new Westcor MicroPACs support a wide range of customer power requirements and are ideally suited for distributed power architectures.

System designers seeking the flexibility to partition multiple voltage outputs rather than use two separate power supplies can configure MicroPACs with a combination of four high-performance VI Chip BCM high-voltage bus converters, which may be configured as single outputs, parallel outputs, or a series output with integrated current sharing. For applications requiring higher power levels, MicroPACs can be configured in arrays with box-to-box current sharing.

MicroPACs operate at full load over a wide temperature range (-40° to +55°C) and are ruggedized for harsh environments. Offering an economical alternative to competing MIL-class power systems, MicroPACs meet MIL-STD 810 standards for shock and vibration—up to 7Gs per axis for one hour each, and 40G functional shock—and are therefore well suited for ground vehicle (Figure 1), aircraft and ship transport and usage.

Figure 1
The MicroPACs is an AC/DC power system that meets MIL-STD-810 standards for shock and vibration—up to 7Gs per axis for one hour each, and 40G functional shock—and are therefore well suited for ground vehicle platforms.

DC/DC Full-Brick Conversions

Brick-style DC/DC converters are still a favorite in military designs. More electronics in military systems mean ever stronger appetites for power. Feeding that need, SynQor has increased the maximum rated power level of its 270Vin MCOTS line of full-brick DC/DC converters by raising the lower end of the input voltage range over which they can operate. The new MCOTS-270H line of full-brick converters can deliver 800W of output power while operating over a continuous input voltage range of 240V to 425V and a transient input voltage range of 240V to 475V. The 240V lower limit complies with the requirements for all of the Steady-State conditions specified in MIL-STD-704(A-F), and the higher limits comply with all of the Steady-State and the over-voltage Surge requirements. These MCOTS-270H converters are particularly useful for high power systems that do not need to operate through a Starting Voltage Transient, or that simply have power sources that are more tightly regulated than specified in MIL-STD-704(A-F).

The MCOTS-270H full-brick DC/DC converters are designed to provide isolated DC power for electronics such as power amplifiers, jammers and systems requiring high-powered bus voltages (Figure 2). These converters use SynQor’s synchronous rectifier-based technology to achieve extremely high efficiencies, up to 92% at 800W. The optional built-in current sharing feature allows for easy paralleling of modules for applications requiring more power or module redundancy with limited external components. Switching frequency is constant to provide predictable EMI performance, and the converters can be paired with SynQor MCOTS EMI filters to meet most requirements of MIL-STD-461. The MCOTS-270H converters are offered encased for exceptional performance in harsh environments and can provide full output power at case temperatures between -55° and 100°C.

Figure 2
The MCOTS-270H full-brick DC/DC converters are designed to provide isolated DC power for electronics such as power amplifiers, jammers and systems requiring high-powered bus voltages.

The full-brick converter features include: remote on/off control, very wide +10% to -50% output voltage trim range, remote output voltage sense, input under-voltage lockout, output over-voltage protection, active back bias limiting, thermal shutdown, output current limit, short circuit protection and optional current share. The MCOTS-270H series is designed for 4250 VDC and 100M ohm input-to-output isolation, is 5/6 RoHS compliant, and has a calculated MTBF in excess of 1.2M hours at 70°C (MIL-217).

Chassis Mounted Power Conversion

As box-level rugged systems become more common, the demand for chassis-mounted power converters has been on the rise. Satisfying those needs, Calex offers the 75W QCM Chassis Mount DC/DC converter now available with a DIN mount adapter. The QCM Series offers an input range of 18 to 36 VDC and 36 to 75 VDC with output voltages from 3.3 to 24 volts DC (Figure 3). The QCM is fully encapsulated with easily accessible recessed barrier strips. The package size is 2.65 x 4.20 x 1.00 inches. The QCM is fully isolated input to output. The isolation voltage is 1544 VDC. The operating temperature range of the QCM is -40° to +100°C. The storage temperature for all models is -40° to +120°C. All models feature remote ON/OFF as well as output voltage trim. The voltage trim range is +/-10%. The units are protected by reverse input voltage protection, pulse by pulse current limiting, dead short current limiting and over-temperature protection.

Figure 3
The 75W QCM Chassis Mount DC/DC converter is now available with a DIN mount adapter. The QCM Series offers an input range of 18 to 36 VDC and 36 to 75 VDC with output voltages from 3.3 to 24 volts DC.

UPS Technology Moves Forward

Innovation is also happening in the UPS side of power technology. For its part, Falcon Electric has added a ruggedized wide temperature (-30° to 63°C) extended runtime battery bank option to its popular SSG and SSG-RP UPS products (Figure 4). The wide-temperature-rated batteries provide long back-up runtimes for protecting connected computers and instrumentation operating in harsh environments during a prolonged power outage. The new battery pack gives users over 10 times the battery runtime, compared to Falcon’s standard 2U extended battery pack option.

Figure 4
Ruggedized wide temperature (-30° to 63°C) extended runtime battery bank options have been added to Falcon Electric’s SSG-RP UPS. The new battery pack gives users over 10 times the battery runtime.

The new battery bank carries a UL listing when powering Falcon’s unique UL-listed SSG2.5KRP-1. UL is pending for the remaining models in the SSG and SSG-RP Series wide-temperature-rated UPS product line. The SSGB-1S40-5U 40AH battery bank is a rugged battery option that consists of eight deep cycle, valve regulated lead-acid, maintenance-free 40 amp hour (AH) batteries and two internal one amp chargers. The batteries and chargers are housed in a sleek rackmount enclosure that takes only 5U (8.75 inches) of vertical rack space. The battery banks may be interconnected or “daisy chained” to provide exceptionally long battery runtimes and can be easily added in the field after the SSG units are installed and in service. The SSGB-1S40-5U 40AH is priced at $2,995.

Another interesting trend happening with UPSs is the reduction of size. A recent example from NOVA Power Solutions is the NP560 Series power supply. Only the length and width of a piece of paper, the 1U high unit is an ideal solution for rugged perimeter surveillance, giant voice / indoor voice capabilities, military vehicles, mobile command centers, or any mission-critical equipment. The NP560 provides 560VA/400W of nominal 120 VAC output from an 85-155 VAC  40-70 Hz input with additional 24-30 VDC or 85-260 VAC input options. This wide voltage and frequency tolerance enables the UPS to operate from generators in the field, tactical vehicles or any international power standard. With an optional battery pack, the NP560 operates as a True Online, Double-Conversion Uninterruptible Power Supply (UPS) that powers your system through utility power interruptions.  

Calex
Concord, CA.
(925) 687-4411.
[www.calex.com].

Falcon Electric
Irwindale, CA.
(626) 962-7770.
[www.falconups.com].

Martek Power
Torrance, CA.
(310) 202-8820.
[www.martekpower.com].

NOVA Power Solutions
Sterling, VA.
(800) 999-6682.
[www.novapower.com].

Pico Electronics
Pelham, NY.
(914) 738-1400.
[www.picoelectronics.com].

Rantec Power Systems
Los Osos, CA.
(805) 596-6000.
[www.rantec.com].

RECOM Power
Brooklyn, NY.
(718) 855-9710.
[www.recom-power.com].

SynQor
Boxborough, MA.
(978) 849-0600.
[www.synqor.com].

TDK-Lambda Americas
San Diego, CA.
(619) 575-4400.
[www.lambdapower.com].

Vicor
Andover, MA.
(978) 749-8359.
[www.vicorpower.com].

VPT
Blacksburg, VA.
(425) 353-3010.
[www.vpt-inc.com].

 

LEAVE A COMMENT