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Chapter 2 Power Supply

Chapter 2 Power Supply






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    Chapter 2 Power Supply Chapter 2 Power Supply Presentation Transcript

      • Electricity is a basic part of nature and it is one of our most widely used forms of energy.
      • Electricity is about charge . Charge is a property of electrons and protons which are part of an atom . Electrons have negative charge and are mobile because they have 1/1830 of the mass of the positive proton.
      • Neutrons have the same mass as a proton , but no any charge.
    • Electron
      • Electron in motion is called electric current which we use every day in our homes . In other words, Electricity is simply a flow of negative charged particles, called electrons through conductors like copper wire.
      • In most metals, the nuclei of atoms (protons & neutrons) are bonded together.
      • The pressure the electrons in the wire is called voltage and is measured in units called volts (V) .
      • The amount of electrons moving past a certain point on a wire is called the current, which is measured in units called amperes (Amps or A).
    • Type of electric current
      • Alternating current (AC)
        • electrons flow in one direction around a continuous path
      • Direct current (DC)
        • electrons alternates direction back and forth
    • Power Supply
      • Designed to convert 110 volt or 230 volt AC power from the mains to usable low-voltage DC power (12 volt, 5 volt and 3.3volt) for the internal components of the computer.
      • It provides the necessary electrical power to make the computer work. A power supply is rated by the number of watts it generates.
      • Because motherboards, power supplies and computer cases are often sold together and must be compatible with each other.
      • Personal Computer (PC) power supply consists of single box with lots of wires coming out of it to connect various internal components and motherboard of a computer.
      • Understanding power supply units of a PC is very important because any problem in power supply can crash your computer and can corrupt your valuable information (data).
      • Power Supply In a personal computer (PC), the power supply is the metal box usually found in a corner of the case. The power supply is visible from the back of many systems because it contains the power-cord receptacle and the cooling fan
    • The interior of a power supply.
    • WARNING: Do not open the power supply, it contains capacitors which can hold Electricity (WHICH CAN KILL) even if the computer is power off for a week, if not longer
    • Power Supply Form Factors
      • Form Factor : industry term for the size, shape, type and external connector.
      • There are approximately eight industry standard
      • Form factors for power supplies. They are:
      • Personal Computer / Extended Technology (PC/XT)
      • Advanced Technology (AT) Desktop type
      • AT Tower Type
      • Baby AT
      • LPX
      • Advanced Technology Extended (ATX)/NLX
      • SFX
      • WTX
    • Power Supply Form Factors – PC/XT
      • first used in IBM desktop in 1983.
      • Called as extended technology.
      • placed into the rear of the case – right hand side
      • controlled by an up/down toggle switch
    • Power Supply Form Factors – AT (Desk Type)
      • “ AT” – advanced technology
      • introduced by IBM in 1984
      • increased in size.
      • The original AT power supply provided 192 Watts ,
    • Power Supply Form Factors –AT (Tower)
      • Introduce tower style cases
      • Introduced the first remote power switch.
      • The control wires for the switch were passed through the same hole in the front of the power supply case that was used for the motherboard and drive connector bundle.
    • Older AT Style Power Supply
    • Power Supply Form Factors – BABY - AT
      • smaller version of the original AT form.
      • It has the same height and
      • length, but is about 2" less in width.
      • It has the same motherboard connectors and drive connectors as the AT
      • introduced around the time PCs began to grow.
      • The Baby AT power supply was made in both a tower and desktop configuration,
      • the most popular design over a decade.
    • Power Supply Form Factors – LPX
      • The LP in LPX stands for low profile .
      • They are also often called slimline power supplies because LPX cases are often called slimline cases .
      • size reduction. The height in particular of the power supply is significantly reduced, facilitating the design of much smaller, consumer-oriented PCs.
      • The connectors of the LPX form factor power supply are the same as that of any AT families.
      • use remote power switches.
      • made in large quantity and millions of these power supplies are still in use.
    • Power Supply Form Factors – ATX/NLX
      • Introduction by Intel in 1995 .
      • The Advanced Technology Extended (ATX) form factor was the most significant change in system design
      • Now standard in the marketplace.
      • The NLX motherboard and case form factor designed to replace LPX.
      • The ATX power supply appears virtually identical to an LPX power supply in terms of its dimensions and component placement.
      • The ATX power supply design consist:
      • True Standard
      • Soft Power
      • Additional Signals
      • Changed Motherboard Connectors
      • Modified Fan Direction and Placement
    • Power Supply Form Factors – ATX/NLX Rear view
    • Power Supply Form Factors – SFX
      • In 1997 Intel introduced the new microATX form factor, based upon the original ATX form factor.
      • In 1999, Intel produced the FlexATX addition to the microATX specification, detailing plans for an even smaller motherboard and case standard.
      • Later, Intel created the SFX power supply form factor, which they may optionally use.
      • “ S” stand for small
      • The specified output rating of the SFX power supply is 90 W. This is sufficient to run rather small systems with low-powered CPUs and few peripherals
    • View of the top and side of an SFX power supply, showing the top-mounted cooling fan.
    • Power Supply Form Factors – WTX
      • WTX was introduced by Intel in 1998 , and revised in 1999.
      • designed specifically for workstations. W in WTX stands for Workstation.
      • WTX defines a standard for motherboards, cases, and power supplies.
      • It is designed in a modular way from the ground up to allow it to meet the needs of large, multiple-CPU systems now and in the future .
      • The motherboard is mounted on a special mounting plate
      • which gives motherboard makers the flexibility to design boards
      • suit the needs of larger system
      • supplies large power
      • Industry standard PC/XT, AT, Baby AT, and LPX motherboards all use the same type of main power supply connectors. These supplies feature two main power connectors (P8 and
      • P9) , each with 6 pins that attach the power supply to the motherboard.
      • Modern motherboard uses a 20 or 24 pin P1 power connector . Some motherboards may require special 4-, 6- or 8-pin connectors to supply extra power . The ATX, NLX and SFX power supplies have 20-pin connectors that attach to the motherboard.
    • Power Supply Connections to Peripheral Hardware - MOLEX
      • the most commonly used
      • provides both 12 volt and 5 volt
      • hard disk drives, CD Rom drives
    • Power Supply Connectors to Peripheral Hardware - Mini Connectors
      • supply power to floppy drive
      • standard connector for 3.5 inch floppy disk
      • four pins out and usually four wires
    • Power Supply Connectors - SATA Connectors
      • Serial Advanced Technology Attachment (SATA) designed for transfer data to and from hard disks and optical drives.
      • SATA hard drives
      • need a special 15 pin SATA power connector .
    • Power Supply Connectors - Splitters
      • using splitters to create more connections
    • Power Supply Connectors - Mini Adapter
      • most systems come with a single mini connector
      • for an additional mini connector use mini adapter
    • Computer Cases
      • Usually made of metals
      • Holds all the primary electronics
      • Three general rules to consider:
        • the bigger the box, the more component it can hold
        • the more compact the box, the less expansion potential it has
        • smaller cases that come with a power supply usually have lower wattage
      • Desktop computer cases are for the models of PC that sit on the desk horizontally .
      • As far as computer cases go, desktops have the least amount of choice available on the market.
      • Although the majority of new PC's come with towers or mini towers, some are still built using desktops case.
    • Full Tower
      • Following factors need to be considered while choosing a computer case:
      • Size
      • Cooling
      • Installation features
      • Power supply
      • Convenience Items
      • Style