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What is a PSU? PSU meaning

What is a Power Supply Unit (PSU)?

Electricity travels a long, complicated journey; from its generation to our consumption. Today we are going to look at an important piece of hardware that is an essential gatekeeper through which electricity must pass to power on our beloved computers.

This equipment turns the violent generated electricity into soul food for our delicate electronic devices. It is called the PSU. Now let us explore the PSU, meaning we will look at what it is and why it matters.

PSU meaning?

PSU stands for Power Supply Unit. It is often misidentified as the Power Source. Power Supplies only convert an existing Power Source into a form that is suitable for use by electronic devices.

A PSU is a necessary stage in electricity’s life cycle from generation, transmission, distribution to consumption by computing devices. A PSU can be compared to the stomach which digests food into nutrients, which are a more suitable energy source for the body.

All computers need a power supply unit to water down and regulate the voltage and current. Some PSUs stand as independent units whereas others are internalized into the device’s structure. 

PSU main functions

Power Supply Units (PSU) generally convert high alternating current (A.C) voltage to stable direct current (D.C) voltage.

A.C to D.C power supply units (PSU) are the most common kind and they are plugged directly into A.C wall outlets.

D.C to D.C power supplies exist that convert D.C power sources from one voltage to another. D.C to D.C PSUs are rare on the market and are usually only used within cars or similar D.C power sources.

Besides converting voltage, Power Supply Units also regulate the D.C output to provide a constant and stable D.C supply. PSUs also supply different D.C voltages to suit different hardware component’s needs. 

Types of PSU

There are three main types of supply units, which are non-modular, semi-modular, and fully modular. 

Non-modular PSUs 

They have fixed connecting cables that cannot be removed. This makes them cheaper and faster than their maneuverable counterparts.

This is because they have fewer points of connection, which minimizes loose connections that cause higher resistance. Higher resistance causes drops in voltage which affects performance.

Their major drawback is that the cables are clunky and inflexible which blocks ventilation and also looks ugly.

Semi-modular PSUs

These units only allow connectors for some non-essential components to be detachable.

This was done to improve the cosmetic appeal and ventilation within the housing.

However, the tradeoff is the added electrical resistance from the extra connectors that cause a minute drop in performance.

Fully modular PSUs

They have cables which are all detachable. This was done to aid airflow and aesthetics as fixed cables are inflexible.

These are the most expensive type of PSUs on the market today.

PSUs can also be further classified into another 4 modes of operation based on how they deal with electricity. These classes are Brute Force, Linear, Switching, and Ripple Regulated PSUs.

PSU Efficiency

Efficiency is how much power output exists compared to the power input. It is a ratio measured in percentages. Power Supply efficiency is a major topic around PSU grading and performance.

It’s so important that the cost of this hardware largely depends on its Efficiency and Power Capacity. So it is no surprise to discover how meticulous the considerations for PSU Certification are.

Efficiency, % = (Power Output / Power Input) * 100

For instance, to calculate efficiency for a PSU that consumes 125w to give out only 100w.

Efficiency, % = (100w / 125w) * 100

= 80%

Therefore its Efficiency = 80 %  at a load of 100w.

Power Output is also called LoadMaximum Continuous Load that a Supply Unit can support is called Rated Load. PSUs are graded by calculating their efficiency under different levels of load.

Below is a table containing the different PSU certifications and their accepted efficiencies under different loads.  

PSU efficiency

The remaining power lost due to inefficiency becomes heat generated during the conversion process.

More efficient supply units last longer because of less damage from the heat.

Less efficiency equals more heat generated which is equal to more damage caused by heat leading to a shorter lifespan.

The efficiency of PSUs can be increased by a better choice of materials used in the manufacturing of Supply Units.

The best operating efficiency of a power supply unit (PSU) is found around 50% of the rated load. Thus, it is recommended to buy a Power Supply Unit whose maximum power capacity is twice your system’s power demand.

Do this and your system will run at optimal efficiency with little risk of fireworks. You would even have the capacity for future upgrades.   

What PSU should I buy?

Whether you need a DC to DC or AC to DC power supply unit, it’s available on the market. The hard part is knowing where to look.

Good advice when buying Power Supplies is to always choose quality goods over cheap products. Reputable brands are a safe bet for important hardware that can go the distance.

Cheap PSUs often have few protections in place to guard against electrical surges or short circuits. Some unscrupulous companies might even use false ratings on their labels which will fry all your delicate hardware like an egg.

Some shady manufacturers even exchange the continuous power capacity of their PSUs with the brief peak capacity. Don’t become a victim, buying a cheap PSU will only cost you more in the long run than the money you will save now.

Some good brands that make good quality PSUs include Corsair, Seasonic, EVGA, and Cooler Master. Remember, always buy from reputable sellers where quality is guaranteed and the customer is protected.

What’s next for Power Supply Units (PSU)?

Power Supply Units (PSU) meaning in our daily lives doesn’t need embellishment.

It’s place is undisputed. All further improvements on this technology will focus on reducing size, increasing efficiency and eliminating noise.

Power Supplies are still constantly improving, from the days of physically mobile components to now having oscillating circuits. Who knows what will be the next breakthrough.

Technology is changing every day. We can only keep our eyes peeled, ready for the next breakthrough that is sure to come.



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