Military Power Supplies: Why are they important?

Electronic systems of all types require power supplies. Commercial and even industrial power supplies are sufficient for many, even the majority of uses. Demanding military applications, including military aircraft, naval vessels, ground vehicles and all manner of defense apparatus, operating in extreme conditions, require only the best technology. A quality military power supply must provide consistent, highly reliable and technically superior performance. After all, lives are depending on it.  

Consistent and Reliable Military Power Conversion

As a trusted source of AC and DC energy, military power supplies must consistently perform when deployed in the field. Configuration controlled power supplies for military applications are designed with a higher mean time between failure (MTBF) than power supplies for commercial or even industrial use. Rigorous design review, quality control standards during manufacturing, feature redundancy and often in-field diagnosis tools are employed to ensure military power supplies are exceptionally reliable.

Military Power Supply Standards

To achieve the required level of reliability, military power supplies are subject to regulations, commonly referred to as military standards. The standards describe very specific requirements for the type and quality of parts, design, and applications for use. These standards for military power supplies include:

MIL-STD-461 Electromagnetic interference (EMI) characteristics – This military power supply standard describes how to test equipment for electromagnetic compatibility.

MIL-STD-704 Aircraft Electrical Power Characteristic – This military standard defines many of the engineering and feature requirements of military power supplies, both AC and DC systems, used on military aircraft, fixed and rotor.  

MIL-STD-810 Environmental Considerations – This military power supply standard defines the environmental requirements a military power supply manufacturer must design for. The standard further defines the chamber test methods that replicate the effects of environments on the equipment rather than imitating the environments themselves. Additional tests may also be defined by the design engineer, such as the harsh environment moisture test.  

MIL-STD-1275 Characteristics of Electrical Systems in Military Vehicles – This military power supply standard covers the limits of steady state and transient voltage characteristics 28 VDC electrical power systems for military ground vehicles.

MIL-STD-1399  Interface standards for shipboard electric power - This military power standard establishes electrical interface characteristics for shipboard equipment utilizing AC electric power, to achieve compatibility between end user equipment and the electrical systems of the ship.

MIL-S-901D Is the military specification for High Impact mechanical shock which applies to  equipment mounted on ships. The purpose of the standard is to verify the ability of shipboard equipment to withstand shock loads resulting during wartime service due to the effects of nuclear or conventional weapons. Watch this video for an example of a Milpower Source Naval UPS being subjected to a hammer test associated with Mil-S-901D compliance. The unit operated normally before, during and after the test sequence.  

An additional standard to be aware is one established by the VMEbus International Trade Association (VITA) committee.  The specification of greatest relevance to power supply design, specifically VPX power supplies, is ANSI/VITA 62-2016.

This defines the power supply requirements for a module designed to power systems that support a VITA 62 slot on the VPX backplane, commonly structured in a chassis arrangement. Power supplies designed for VITA 62 compliance use the standard VPX 3U/6U form factor and comply to the requirements defined in VITA 48.0. VITA 62 also specifies the connectors that mate properly with a VITA 62 compatible backplane.

MOTS, COTS and Custom

Military power supplies, as are most of the components in the defense supply chain, are available in three common broad categories of configuration. These include MOTS (Modified-Off-The-Shelf or Military-Off-The-Shelf), COTS (Commercial-Off-The-Shelf) or MIL-COTS (Military Commercial-Off-The-Shelf) and Custom Solutions. While the terms are common, each company has a distinct way of defining the terms, making it important for the customer to both communicate their power supply objectives and understand how the supplier defines these terms. Milpower Source defines the terms as follows as it pertains to military power supplies. 

MOTS - When supply a MOTS power conversion solution, Milpower Source starts with an existing military power supply design, from the existing catalog of thousands of proven designs, and modifies the configuration to meet the customers specific requirements. 

COTS - Milpower Source views this as MIL-COTS. A wide variety of off-the-shelf units are available in standard configurations -- look for the -10X models on individual product pages.  All of the product available, regardless of the configuration or technical specifications, is already designed for military use. Milpower is after all the company name! 

Custom Military Power Supplies - Milpower Source design engineers can and will be pleased to solve any military power supply design challenge. In many cases, new requirements lead to a modification of an existing power supply design, this is typically the most expeditious path to a qualified military power supply. When dealing with all new requirements though, the Milpower Source engineering team, as they have done hundreds of times, will design and deliver an exceptional custom military power supply. 

Sensor Open Systems Architecture (SOSA)

The SOSA Consortium is developing a a body of materials and reference architectures the military and defense contracting community can coalesce around. The objective is a common framework of military design standards, including those applicable to military power supplies, which will operate as guidelines for design and development. Visit the SOSA site here

VMEbus International Trade Association (VITA)

Milpower Source is a proud member of VITA. Customer seeking to adhere to or incorporate aspects of the VITA standards into a future military power supply can turn to Milpower Source with confidence. With in-house VITA experts, Milpower Source can support a customer's requirements and guide the design process to align with VITA standards, thereby supporting system compatibility and reducing risk.  Lear more about VITA here

Beyond the Standards 

Military power conversion solutions adhere to specifications, often defined by the application objective, which guide the production of these power sources. The end application, be it aircraft, ground, shipboard or any manner of defense related platform all have certain feature and environmental requirements. The power supplies input/output voltage, shock, vibration, frequency, electrical noise, and abnormal condition management are all regulated by these detailed specifications.  

Size, Weight and Form  

Military power supplies, more than commercial or industrial power supplies, routinely need to address size, weight and form in the design process. Weight for airborne military applications is a particular consideration, requiring higher degrees of engineering expertise. While the VPX form factor has become common, there is not a consistent form standard in the military environment, often resulting in power supplies being design to fit the available space on an application.            

When to use military power supplies

Military-grade power supplies should be used in all mission critical defense related applications These sophisticated power supplies are especially important in harsh or rapidly changing environments, when system failure is not an option and especially when lives are depending on reliable performance. Though the cost is higher than commercial units, overall when the units last longer and prevent the failure of other expensive electronics the peace of mind is worth it.

Total Cost of Ownership

When procuring electronic products for military applications, cost is of course a major consideration. The procurement cost is the obvious expense but there are other costs, not always obvious at first glance because they incur later. The affect that they have on the overall cost for the program is significant. For more information intended to assist program managers, engineers and procurement individuals in understanding the factors that should affect the procurement decision beyond the immediate cost of a unit visit this page

For more information about military power supplies and other defense related news topics visit this page for a list of relevant trade publications.   

Selecting a Military Power Supply

When a military power supply is required, it is best to work with a proven expert. An experienced military power supply design and manufacturer, with expertise in mechanical and electrical requirements, is a good option.  Milpower Source offers a wide variety of military power supply product options. Visit the product family of interest and identify a base unit, then get in touch to discuss the specific requirements of your application.    

 

- For offline reference, download the Product Selection Guide

Next, contact a design consultant to discuss your application and military power conversion requirements at (603) 267-8865, sales@milpower.com or via this contact page.  

The Milpower Source Difference

Milpower Source has been designing and manufacturing military power supplies for more than 40-years. Milpower Source’s wide range of military power supply solutions are incorporated into all manner of fixed and rotorcraft aircraft, drones, naval ships, ground vehicles, C4ISR, radar arrays and fire control systems.  Learn more about our design process and how we support the defense communities’ military power conversion requirements here. 

 

 

 

 

 

Milpower Source
P.O. Box 810
7 Field Lane
Belmont, NH 03220
United States
Phone: (603) 267-8865
Fax: (603) 267-7258
sales@milpower.com
© 2019 Milpower Source - All Rights Reserved