Ground Defense Power Systems
Power supplies for the ground defense and in particular the ground vehicles military sector present some very specific requirements for the power supply designer. The first and most obvious requirements are the environmental conditions such power supplies are exposed to, secondly are the electrical input requirements and having a power supply operate from a vehicle battery which can fall to very low voltages when starting and cold cranking the engine.
The military standard MIL-STD-1275 defines the interface characteristics of 28Vdc Input Power to utilization equipment in military vehicles. It defines the operating voltage limits and transient voltage characteristics of the 28Vdc electrical power at the input power terminals of the power supply.
A ground defense vehicle power supply must be able to handle:
Steady state DC input voltage of between 20V and 33V
Input voltage (droops) to 12V, lasting up to 1s and repeated at intervals of 1s
Input voltage (droops) to 16V lasting for up to 30s
The power supply must also be able to accept the following surges and transients and not emit surges and transients exceeding the same limits.
Voltage surges of up to 100V for 50ms to 33V at 500ms, with maximum single surge energy of 60 Joule
Voltage (droops) to 18V for 0.5s, to 20V at 0.6s, with maximum single surge energy of 60 Joule
Voltage spikes up to 250V for 70µs to 100V for 1ms with maximum single spike energy of 2 Joule
Voltage spikes up to -250V for 70µs to 18V for 1ms with maximum single spike energy of 2 Joule
Environmental & Other Considerations for Military Ground Vehicles
Military ground vehicles present a very wide range of environmental challenges, predominantly for temperature, vibration and hermeticity. A variety of vehicle types are used by the military, some wheeled and others with tracks, each presents its own vibration spectrum in terms of frequency and acceleration levels, here, MIL-STD-810 helps define the requirements.
Vehicle type and where it is used have a major impact on the vibration spectrum. The same vehicle will have a very different spectrum when used in one location compared to another. A Viable Power custom ruggedized power supply can offer the best solution for the application.
In addition to vibration, ground vehicle applications also present extreme temperature, water, dust and mud for the power supply to withstand. For an externally mounted unit, a water-tight solution using conduction cooling, with a robust finish is a preferred approach. For internally mounted units, the requirements may be less stringent and will be appropriately addressed by the design team.
Viable Power’s expertise and experience professionally addresses our customers’ power supply product needs for these demanding applications. As with all Viable Power products, they are designed and manufactured in our 13,000 square foot facility in Pointe-Claire, Quebec in Canada.
After a series of qualification level tests on a qualification unit, the power supplies are manufactured in accordance with the requirements of IPC-J-STD-001 Class 3. Each product undergoes stringent quality inspections to IPC-A-610 Class 3 during the manufacturing phase, followed by a series of electrical performance and environmental stress screening tests which include vibration and thermal cycling.
Need More Information About Our Ground Defense Applications?
If you would like more information about our services and products for the ground defense applications, please feel free to contact us or complete our request for proposal form and one of our experts will contact you.
