Have you ever wondered how the military powers all their equipment? It’s not as simple as we have it – can’t just call the power company and boom, there was light. There are power supplies in virtually every military electronic system. 

These devices come in all shapes and sizes. On matter functionality, it’s not that different from their commercial counterparts. They too have advanced power conversion solutions like AC/DC, DC/DC and other configurations.

How Different Are They?

The main difference between defense power supplies and their commercial siblings has been reliability. See how annoyed you get when there is a power outage? Well, imagine that in the military. 

It is no longer simply a matter of inconvenience but potentially catastrophic failure and loss of life. Military power supplies were designed with a long mean time between failure as the main goal being delivering years of trouble-free operation.

What the Scene Is Like Today

The standard has remained reliable, with their MTBF being way higher than those of their commercial counterparts. On top of that, they are being upgraded every two years – just like consumer electronics I might add. 

Every upgrade renders previous generations obsolete. This spells out obsolescence and availability issues. For long term reliability, the ability to recognize pending failure has become very important.

When it’s all said and done, military grade supplies have to meet specific requirements. These requirements include detailed guidelines for selecting components that are part of each supply not to mention a rigorous set of design rules to ensure manufacturability.

Let’s look at some of these guidelines:

Guidelines for Military Power Supply

Part Selection and Design

Part selection is a very important step in designing defense power supplies. All components that will be part of the product have to be approved and qualified by the manufacturer for use in any military system or be qualified for the application by the manufacturer of the power supply. This process serves 2 purposes:

• Establish that a stable source of supply for the component exists and adequate control procedures are in place
• Prevent the usage of restricted materials that can degrade during normal usage.

Over time, life cycles of advanced power conversion solutions have dwindled in importance although that remains a requirement in military electronic systems. Military electronic systems must be replaceable or at least repairable throughout their lifetime. This places extra demands on military grade power supplies manufacturers.

Application Requirements

Different branches of the military have published detailed sets of requirements that establish what is to be expected of power supplies from all military systems deployed in the field. These standards focus on performance issues as well as the working environment which can impact reliability.

Input voltage conditions for tactical military applications cover electromagnetic compatibility and input levels. Electromagnetic compatibility standards demand the amount of conducted RF energy the device must be able to withstand and still operate properly. 

It usually is 40 dB or more. Commercially available filters that meet the requirements for commercial noise suppression cannot achieve this level of signal rejection. 

With all that in mind, it is safe to conclude that each military power supply application must be approached individually to construct filters and maintain proper impedance matching characteristics to eliminate radiated noise at the input.

Most common power supply devices adapt alternating current power from an electrical source to the voltage, current, and frequency that the device needs. Stepping the voltages up or down, followed by filtering, is how it’s done. The device receives electrical power in a secure and regulated manner as a consequence. 

Other energy sources, such as solar or chemical energy, can be converted into electrical energy in some models. In larger devices like desktop computers, a power supply is either internal or external, as seen in laptops and phone chargers.

Programmable DC Power Supply

The output voltages can be remotely controlled by a programmable DC power supply utilizing an analog control signal that can be altered by a rotary switch that is frequently seen on the front panel.

Current and voltage output are two often modifiable power supply features. Alternating current power supplies allow for the frequency to be programmed as well.

Electronic Load 

Manufacturers of power supplies must dynamically test their products. Electronic load provides them the ability to quickly and cheaply simulate various power levels in place of using fixed-resistor banks of different sizes. It also aids in the analysis of a wide variety of power sources, including batteries, fuel cells, and electromechanical sources like converters and inverters.

It may also be used as a high-speed current modulator to boost a power supply’s efficiency. In such cases, just a part of the rated capacity of the power source is needed. The voltage across the load is extremely low when the current is modulated to its maximum. As the current is modulated off, the voltage increases to its highest point.

The load power needed for a current modulation from zero to maximum typically equates to one-quarter of the operating voltage times the current rating plus a buffer.

The Dc to Dc Converter

They are employed to modify the voltage level. They are constructed around a wiring system that makes use of electronic switching technologies. 

They can accommodate both applications requiring very low voltage and those requiring very high voltage, and it is most frequently used when a linear regulator is not the optimum solution.

The Function of DC to DC Converter

Numerous electrical equipment and circuits in a variety of applications require a voltage that is either lower or greater than what the power source provides. 

In such cases, a circuit is required to convert or modify the electrical voltage level of the incoming power. The dc to dc converter makes it possible to transfer electrical power effectively, which makes it ideal for use in gadgets like mobile phones and laptop computers.

Conclusion

Think about the many parts that make up your device and how each one will require a specific current and voltage to function properly. The screen display won’t be powered by the supply voltage because it is the device’s CPU. 

Therefore, in order to handle the power supply of various voltage domains, you will require a converter that can either step up or step down the voltage level.

Let us break it down a bit for a better understanding. If you were keen in science class, you probably remember the teacher mentioning that DC stands for direct current. Direct current is a unidirectional flow of electric charge – the direct opposite of AC, alternating current.

Simply put, a defense DC-DC converter is an isolated, thick-film hybrid converter for flight critical applications with extreme temperature requirements. They efficiently produce a regulated DC voltage from a source that may or may not be well controlled to a load that may or may not be constant.

DC-DC Conversion

A DC-DC converter is a type of electronic circuit that takes DC source and converts it from the current voltage into another voltage. Now I know this sounds like describing a word with the word but it’s not quite it.

The conversion sometimes can involve increasing or decreasing the voltage. A perfect example of DC-DC conversion is your portable DVD player. Whenever you are going to work jamming to some music, the player has to draw the power from the car battery.

Now too much power may damage it and too little power may not run it. That is exactly why DC-DC conversion is important. The applications of a military DC DC converter may not be as simple and melodious but the idea is pretty much the same.

They for one need to be ruggedized which leads me to a side note:

Ruggedized Power Supply

A rugged power supply is a form of power supply capable of withstanding a variety of unfavorable environmental conditions – however challenging they may be. This comes in handy in military applications. These power supplies were built to withstand extreme environmental and weather conditions like extreme altitude, temperature, vibrations and shock.

Ruggedized power supplies are related to DC-DC converters in that they themselves are DC-DC converters. Regardless of where these power supplies are being used, their purpose is: provide regulated voltage.

Regardless of the source input, the output should be converted to DC. There are both rugged AC-DC and DC-DC power supply units. Just about all electronics require regulated power supplies to function correctly. Without regulated power supply, large fluctuations can occur delivering unsuitable power needs. Regulating the power maintains steady power supply which prevents outages and avoids overloads.

Using non-rugged power supplies in non-ideal conditions will have you having to provide continual maintenance, deal with breakdowns and downtime of course.

Applications of Rugged Power Supply

Ground Vehicles

A rugged vehicle power supply is useful both in and outside of the military scope. Just about any car needs to withstand a host of climates and environmental conditions. Vehicles often travel over rough terrain through dirt, sand, humid areas and marshy areas. On top of using rugged power supplies, military vehicles need to meet other specific codes and standards.

Aerospace

When it comes to manufacturing power management solutions for the aerospace industry, engineers must consider the effects of altitudes and the accompanying changes in weather.

Just like in ground vehicles, vehicles for military use have to meet other standards and requirements on top of using rugged power supplies.

Shipboards

Ship environments don’t exactly scream optimal conditions for electronic systems with the demanding external conditions. This rules out a significant amount of power supply options but no matter, ruggedized power supply to the rescue. These rather harsh environmental conditions necessitate precision-engineered power management solutions that of course meet the standard Naval requirements.

How a DC-DC Converter Works

Like I had earlier explained, DC-DC converters basically change the voltage, sometimes by increasing it or decreasing it.

Boost converters increase the voltage from a power source. You could have a power source of only 10 V and a boost converter kicks that up to 30V. You typically find these DC-DC boost converters in battery chargers or solar panels.

Bult converters on the other hand are responsible for reducing the voltage from the power supply. Remember the 10 V power supply? A DC-DC bulk converter could trim that down to just 5V. Said trimming down is achieved by increasing the current.