PC Power Supplies

A PC power supply, or Power Supply Unit (PSU), is the component that converts mains AC power from the wall socket into the regulated DC power required by all of your computer's internal components.

A high-quality PSU is the foundation of a stable and dependable computer system. They provide clean, consistent energy and ensure all your components function correctly, while also protecting them from electrical issues like voltage surges.

What is a Computer Power Supply?

A computer power supply takes electrical energy from an external source, like a wall outlet, and transforms it into the stable, low-voltage DC power that your computer's components need to run. Essentially, it makes the power from the mains usable for every part of your PC. A clear understanding of what the power supply does is crucial for anyone building their own desktop computer or upgrading existing hardware.

How does a PC Power Supply Work?

A PC Power Supply Unit (PSU) performs three primary functions to safely power a computer:

Conversion: Its main job is to take the high-voltage alternating current (AC) supplied from a wall outlet and convert it into the low-voltage direct current (DC) that all internal computer components use.
Regulation: The PSU doesn't just convert the power; it also regulates it, ensuring that each component receives a precise and stable voltage.
Protection: Modern PC power supplies include a range of built-in safety features. These protect the computer's delicate components from potential damage caused by power grid issues like voltage surges, spikes, or brownouts.

PC Power Supply Types (Form Factors)

PSUs come in several standard sizes, known as form factors. Each type offers different dimensions and features to suit various computer cases and needs.

ATX Power Supply

This is the most common and widely used form factor for standard desktop PCs to convert AC mains power into DC. An ATX power supply offers a great balance of power and compatibility. Their size allows for larger, quieter fans and a wide range of wattage options, making them ideal for everything from office workstations to high-performance gaming rigs.

EPS12V

Often visually similar to the ATX standard, the EPS12V form factor was originally designed for servers and high-end workstations. It typically provides more robust power delivery and additional CPU power connectors, making it a requirement for motherboards with dual-CPU sockets or those with very high power demands.

SFX

SFX (Small Form Factor) is a compact standard designed for space-constrained systems. These smaller PSUs are essential for Mini-ITX and other small PC builds where a full-size ATX unit will not fit. While compact, they are available in a range of wattages capable of powering high-performance components in a small package.

TFX and CFX

TFX (Thin Form Factor) and CFX (Compact Form Factor) are even more specialised Power Supply Units (PSUs), designed for slimline and compact OEM (Original Equipment Manufacturer) desktop systems. They feature a narrow, elongated shape and are less common in the custom PC building market, but are often found in pre-built office PCs.

Benefits of ATX Power Supply

The ATX form factor is the most popular standard for desktop PCs. Its design offers a combination of power, compatibility, and features that make it the ideal choice for several different systems.

Key benefits include:

High Wattage Capacity: The larger size of ATX PSUs allows them to support a wide range of power outputs, from efficient low-wattage models to high-performance units capable of delivering over 1000 watts.
Wide Range of Connectors: ATX power supply units come with a comprehensive set of connectors to power all standard components, including the motherboard, CPU, graphics cards (PCIe), and storage drives (SATA).
Superior Cooling and Airflow: Their larger dimensions can accommodate bigger, more efficient fans (typically 120mm or 140mm). This results in better cooling performance at lower RPMs.
Greater Efficiency: The ATX market is highly competitive, leading to a wide availability of high-efficiency models. This means less wasted energy, lower heat output, and reduced electricity costs.

How to Choose the Right Computer Power Supply in NZ

Choosing the right Power Supply Unit (PSU) is one of the most important decisions when building or upgrading a PC in NZ. Consider these factors to make an informed choice.

Determine Your Wattage Needs: Calculate your PC's peak power draw and choose a PSU with 20-30% more wattage for efficiency and future upgrade headroom.
Check the +12V Rail: Verify the +12V rail provides enough amperage (Amps) to reliably power your specific CPU and graphics card.
Look for the 80 Plus Rating: Choose a PSU with an 80 Plus certification (e.g., Bronze, Gold) to ensure better energy efficiency, less heat, and lower electricity costs.
Ensure the Correct Form Factor: Confirm the PSU's form factor (ATX, SFX, etc.) matches your PC case specifications to ensure it will physically fit.
Prioritise Quality and Safety Features: Look for essential safety protections (like OVP, OPP, SCP) to safeguard your components from electrical faults and ensure stable power.
Consider Eco-Friendly Standards: For better eco-credentials, check for compliance with standards like RoHS and ErP/EuP for safer materials and low standby power use.

Applications of PC Power Supplies

While every PC requires a Power Supply Unit (PSU), the specific demands placed upon it can vary dramatically depending on the application.

Gaming Desktops: High-performance gaming rigs require high-wattage PSUs with strong +12V rails to power demanding graphics cards (GPUs) and CPUs.
Office Workstations: For standard office and business PCs, the focus is on reliability and efficiency. A lower-wattage, high-quality PSU is ideal, ensuring quiet operation and long-term dependability.
Home Theatre PCs (HTPCs): These systems are built for media playback and often use small form factor cases. The priority here is quiet or silent operation, so a highly efficient SFX power supply with a quiet fan is the preferred choice.
Industrial and Server Systems: Industrial PCs, servers, and rack-mounted systems demand maximum stability and often 24/7 operation. They typically use robust EPS12V or redundant power supplies designed for long-term reliability and easy replacement in critical environments.

Ordering PC Power Supplies from RS New Zealand

Power your next PC build or upgrade with a reliable power supply from RS NZ, providing stable DC power for all your components. As a leading distributor, we stock a wide range of ATX and other types of PC power supplies from trusted manufacturers like Seasonic, Nipron, and Phoenix Contact. Explore our full online selection to find the perfect Power Supply Unit (PSU), uninterruptible power supply, or DIN rail power supply for your next project.

Ordering from RS is designed to be a quick and straightforward experience. Simply select the power supply you need, add it to your online basket, and complete your purchase through our secure checkout process. We offer a variety of payment options to accommodate your needs. For complete information on delivery times, shipping rates, and our service coverage within New Zealand, please visit our dedicated Delivery Information page.