Custom Military Power Supplies Extreme Conditions and MIL-STD Power Supplies Military standards (MIL-STD) in terms of power supplies refer to a set of predefined tests that need to be conducted on product designs to ensure that a piece of equipment is fit for purpose in extreme military operations. On the battlefield you cannot have equipment fail, irrespective of what the equipment is; as it may compromise field operations. Originally MIL-STDs were developed as commercially available canned products where not designed to be dropped out of aeroplanes or be opened independent of a can opener. Spoilage was also a concern and so internal coatings and linings were improved to reduce the potential of this in many cleaver ways. To ensure a product is to MIL-STDs and therefore fit for purpose, extensive test methods were developed and continually improved; ensuring each new product meets the current needs of a modern battlefield.
Customisation of Military Power Supplies MIL-STD power supplies are used in many diverse applications. As such their designs are purely dependent on that requirement. While you can get standard ‘off the shelf’ products you can also get light and full customisation alternatives. While this sounds very ambiguous in terms of quality, all designs that are produced still have to pass MIL-STD testing. MIL-STD testing requires many units to be destructively tested, this then raises the question of is this economic to do. Full product customisation would require completely new testing to be conducted which takes time. The alternative is to have partial customisation allowing for a lot of the testing to have been already conducted and ‘passed-off’. However, why do you need to customise anything? This could be to add connections or remove redundant systems, reduce the size, and change the shape to fit a custom mounting on a military platform. Following the adage ‘form, fit, function and cost’. Here cost is optimised with quantity to offset addition testing required to pass MIL-STDs, or cost is offset through the platforms performance that integrates a more expensive customised unit.
Military Usages Military platforms can be very diverse and require different specialist power solutions. Designs must not produce noise or allow the ingress of dirt that could affect its performance and require maintenance activities. From an operations perspective this is great however from a design perspective it can be challenging. Even low powered sat-navs for marine applications that are sealed against water is a challenge to produce. In sealed solutions high conduction interfaces are used to distribute heat which cools the heating components. However, the specific heat capacity and therefore the volume of material needed to get heat away from the heat sources needs to grow in size; this can increase the weight and size of the device to maintain a stable power supply.
As a designer of a power supply that needs to meet a power demand, do you then need to go to the client and state the various design parameters that are creeping outside the design boundary of the specification? It may be that the design specification for the military platform is incorrect in so much as it treats the power supply as an isolated module. Instead, it could be that you can get the shape, weight and performance of the sealed system by asking that an external interface acts as heat-sink to improve the conductive volume outside of your box. This could mean that the specification for the platform taking the power supply will need to be modified and a more integrated design of the platform and power supply created. For instance, if the power supply is for aerospace use, could it be mounted with a heat-sink taking the excess heat to an acceptable heat vent.
Design Challenges Most designers these days in industry assume an independent module design and dislike communication with other design teams. This is something to bear in mind when you are defining customisations. Has the client provided a list of needs that you then base your specification on that is incorrectly assumed? Only through better communication and team interaction can you get the best customised design for your products purpose. For information on customized military power supply please contact Titan Power Systems