Computer power supply  types, functions, and components

computer power supply unit (PSU) showing cables and connectors

A computer power supply unit (PSU) is a hardware component of a computer that supplies all components with electrical power. It connects the computer system unit to the power wall socket. From the power unit, the energy is distributed to other components by the use of power connectors.

The main types of power supply form factors are ATX12V, LFX12V, CFX12V, EPS12V, TFX12V, and WTX12V. The main function of PSU is to convert the alternating current (AC) to a direct current (DC) that can be used by the computer. A power unit is made up of connectors, a transformer, rectifier, switches, and a cooling fan. The combination of these and other components enables the PSU to perform effectively.

Types of computer power supply

Power supplies are classified depending on the form factor. This factor should not be confused with the motherboard form factor which is specific to the motherboard. Some of the most common types of power supply units are:

  1. ATX12V: it is an improvement from standard ATX. It comprises of standard ATX form factor. In addition to that, it has increased +12VDC output capabilities and +12 V power connector.
  2. LFX12V (low profile): it is a low profile form factor with a 12V connector. They were designed for small power of 180W to 260W. They are mostly used on picoBTX or nanoBTX motherboards.
  3. EPS12V: they use an 8-pin connector for the processor connection. They were initially designed for server computer motherboards.
  4. CFX12V: it is a compact form factor with a 12-volt connector. They are designed to support Balanced Technology Extended (BTX)based systems motherboards. They have a power rating of 220W to 300W.
  5. SFX12V: They are small form factor power supplies that are designed for use with microATX and FlexATX systems. They have the power of 160W-300W.
  6. TFX12V: the thin form factor power supply optimized for small and low-profile microATX and FlexATX systems. They provide a power range of 180W to 300W.
  7. WTX12V the workstation form factor is designed for high-end workstations and select servers.

Components of PSU

A power supply is one component among many that make up a functional computer. PSU also has its component that helps to convert AC to DC and supply power to the computer. Below are the main components that make up the power unit.

  1. Connectors: These are power connectors that are used to connect different components such as computer motherboard, hard disk, and DVD/CD drive, expansion cards, among others. 
  2. External power source connector: it connects the power cord to the wall socket.
  3. Cooling fan: this is used to cool down the power supply unit
  4. Switches: there are mostly 2 types of switches. One is used to turn on the PSU while the other is used to change the power voltage intake.
  5. Transformer: used to step down or up the incoming power
  6. Rectifier: it is a component that changes power from AC to DC.
  7. Voltage regulator: it regulates the power that reaches specific components.

Types of power supply connectors

From the PSU, motherboard, and other components get power supply using a cable connector that links the component to the power unit. The main components that get power directly from PSU are the motherboard, DVD drive, Hard disk, processor, and expansion card among others. 4 main connectors used are:

  1. 24-pin motherboard power connector: it is used to connect the motherboard to power. They supply all the power that is needed but most other components drive their power from the mainboard.
24-pin computer powers supply connector to motherboard
  1. SATA connectors: they are used to provide power to the SATA storage device and Disc drive. To reduce the number of cables many SATA points are positioned inline on the same wires.
  2. 4-pin Molex connector: they are an old version of the SATA connector and they were used to connect harddisk and front
  3. 4-pin Berg connector: they were used to connect floppy disk drive.

Factors to consider when getting a power supply (PSU)

  1. Motherboard form factor compatibility: power supply unit should be compatible with the motherboard. It should also physically fit within the computer casing form factor.
  2. Wattage output: the standard power calculation of a computer is watts. It is calculated by getting the product of the voltage in (volts) and the current in (amperes). This depends on the power that your computer requires to function at its optimum. The power supply has a rating in watts that you can check. For gaming or high-end performance computers, you need more watts compared to a standard personal computer.
  3. Component connectors: ensure the power connector to motherboard CPU, hard disk and other components are compatible and supply the correct voltage.
  4. Cooling fan noise: power supply comes with a fan to cool the supply. Acquire PSU that has less fan noise.
  5. Efficiency (80 plus rating): power supply unit should offer the highest possible power efficiency. 80 plus rating is used to certify the efficiency of the power supply. A high rating means power is effectively converted and utilized by a computer. This saves on power, reduces overheating, and increases the life span of the PSU.

Functions of computer power supply

The power unit of a computer is a major component. If there is no power then no computer operation. The main purpose of PSU is to power the computer. Other functions include:

  1. Convert AC from wall socket to DC for computer use.
  2. They are used for the cooling system using a fan installed within.
  3. Providing power to the motherboard and other components.
  4. The power unit comes with connectors that are compatible with different motherboard components.

Power supply unit PSU maintenance

PSU is a critical component of a computer for efficient operation it requires to be in good working condition. To ensure it works optimally without problem we recommend the following maintenance routine.

  1. Use a power surge protector. They help to stabilize the power voltage that reaches the PSU.
  2. Use recommended form cleaner to remove dust regularly.
  3. Check the cooling fan is working. Failure of the fan leads to overheating of the power supply.
  4. Ensure the power casing is properly fixed to the computer casing.
  5. Use the right power wattage for the right computer capacity.