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.

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.

The internal power supply design of the medical power supply is influenced by its particular need to adhere to the medical equipment safety standard. However, a medical-grade power supply differs from a commercial type for more reasons than only safety.

The design cycles for medical equipment are often longer than those for other types of equipment, and the power supply provider is sometimes called upon to provide additional design help.

A medical device’s lifespan is often longer than that of other devices. As a result, the vendor of the power supply is usually required to provide support for medical-grade power supplies for a considerable amount of time.

Reliable Power, Designed for Medical Applications

Power that is dependable and accurate is essential in medical settings. The lives of people might be at stake. The medical grade power supply is covered by a warranty and has received medical safety clearances.

All of your delicate medical equipment will receive smooth, consistent, and stable power from the medical grade power supply. The medical power supplies are made to withstand the rigors of medical environments, so you won’t have to worry about power surges, spikes, or outages.

Hospitals, outpatient facilities, surgical centers, same-day care clinics, and any other medical setting can use the power supply. The majority of power items have received medical safety clearances, giving you further assurance.

Switching Power Supply

This approach was created to address a number of issues with linear power supply design. The input voltage is now rectified and filtered at the input rather than being decreased as before. The voltage is then processed by a chopper, which creates a high-frequency pulse train. The voltage is filtered and rectified once more before it exits the circuit.

What types of switching components are used in switching power supplies?

They use precision switching to regulate the operation’s duty cycle. As a result, transistors with improved control capabilities are used the most frequently.

What is a switching power supply adapter?

A power supply adapter enables the use of a power supply whose output was not created expressly for the input being used. Designs for power supplies might include both conversion and adapter circuitry on the same board or just the conversion circuitry.

Where are switching power supplies used?

They are utilized in digital systems including mobile phone chargers, medical diagnostic devices, arc welding equipment, computing gadgets, audio devices, and communications devices.

How Does It Work?

In order to run household appliances or light fixtures, power converters have been converting AC power from the utility grid into DC voltage for many years. Because smaller supplies are required for high-power applications, linear power supplies are now only used in a limited number of industrial and medical applications, where their low noise makes them still necessary.

Switching power supplies have replaced traditional power supplies because they are more compact, efficient, and able to handle high power.

When constructing a switching power supply, there are many various factors to take into account, particularly those that relate to performance, size, weight, and other factors. Since switching power supplies have more complicated control circuits than linear power supplies, many designers find it helpful to incorporate integrated modules in their power supply systems.

Conclusion 

The switching power supply raises the input voltage to a level where the linear post-input regulators to output voltage difference are sufficiently low. The linear regulator then gives the load a cleaner, controlled voltage.

The inadequate transitory reaction is another issue, for instance, it needs some time to respond to and adjust for a step or rapid load shift.