power supply and cooling chapter 4 release 22/10/2010powered by dj

Power Supply and Cooling

Chapter 4

Release 22/10/2010 powered by dj

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Objectives

Discuss the power supply unitDiscuss power supply components and

connectorsDiscuss cooling devices for the systemTroubleshooting SMPS


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Power Supply

Accepts the Alternate Current (AC) supply from the power socket in the wall and converts the AC supply to the Direct Current (DC). Now a days power supplies are available in the range of 250W to 400W

Supplies 3.3V, 5V, and 12V to the different components of the system


Disk Drive Connectors

Motherboard Connector

Power Plug

Power Supply Fan

Cover

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Functions of the Power Supply

Converts AC to DC to supply various components

Generates high-frequency signals during the electric current conversion from AC to DC

Packed in a metal box to prevent damage to system due to high-frequency signals


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Output Voltages

Various voltages provided by the power supply are:• -12 V (Blue) – required by some of the serial ports

• -5 V (White) – required by some older floppy controllers and ISA bus cards

• 0 V (Black) - ground

• +3.3 V (Orange) – required by processor, DIMMs, PCI/AGP cards

• +5 V (Red) – required by voltage regulators, ISA cards, SIMMs and disk drive logic

• +12 V (Yellow) – used by drive motors and cooling fans


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Power Supply Control Signals

Power supplies are operated using different control signals

Different control signals are:• PG Signal (5V Grey)

• Power-On (PS_ON) (5V Green)

• +5VSB (Violet) – Always on when AC power input is active, even if the system is turned off


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Question for GD Time Limit – 3 Mins

What are the different control signals of a SMPS?


Sl. Control Signals1

2

3

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Form Factors of Power Supply – I

Represents size and shape of the power supply

Must match the form factor of the system case and the motherboard


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Form Factors of Power Supply – II

Different Form Factors• Advanced Technology Extended (ATX) –

Uses NLX power supply. Does not have a power outlet to connect to monitor.

• New Low Profile Extended (NLX) - NLX motherboard also uses a riser board for the expansion of bus slots and uses true ATX power supplies.


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Form Factors of Power Supply – III

• Small Form Factor Extended (SFX) – Has two fans to cool the whole system. The output of SFX power supply unit is 90W and is used on smaller systems that do not require a lot of power.

• Low Profile Extended (LPX) - Is also known as slimline form factors because its cases are known as slimline cases. The main goal of this form factor is size reduction.


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What is the significance of form factor on designing the SMPS?


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Components of the Power Supply

Power supply unit consists of different functional components

Different components of the power supply are:• Power Connectors• Power supply Fans


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Power Connectors – I

Electrical connector used to carry DC or low frequency AC power Connectors carrying small amount of power are called signal

connectors

Types of connectors

AT power connectors

ATX power connectors

Standard Peripheral connector

Floppy Drive power connectors

2/3 Pin Mini Plug type

connectors


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Power Connectors – II

AT Power Connector - Two 6 wire connectors named P8 & P9 which are to be connected to the mother board with black wires inside. PC/XT, AT, Baby AT and LPX form factors use AT power connectors

ATX Power Connector – 20/24 pin single connector with mainly 6 types of voltages coming out of it. ATX/NLX form factors use the ATX style power connectors


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What are the different components of a power supply unit?


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Power Connectors – III

ATX Power Connector - 24 pin SMPS connector is built with ATX style of power connector.

4 additional pins number 11, 12 and 23 carry the voltage +12 V, +3.3 V and +5 V respectively. Pin number 24 is connected to the Ground.


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Power Connectors – IV

Standard Peripheral Power Connector (Molex) - Use 4 wire connectors. Hard disk drive, CD/DVD drives use this larger size connectors

Floppy Drive Power Connector (Mini/Berg) - 3.5-inch floppy disk drive use smaller size connectors, called as mini-plug


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PCI-E Connector

Is a 6 pin connector used to provide extra 12 volt power to PCI Express expansion cards. PCI Express motherboard slots can provide a maximum of 75 watts. Many video cards draw significantly more than 75 watts so the 6 pin PCI Express power cable was created.


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Ask the students to write down the output voltage of different color codes of SMPS?


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Power Supply Fan

Used for cooling the system Located at rear end of power

supply unitBall bearing fans are more

reliable and are long lasting as compared to sleeve bearing fans


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Factors to be considered before selecting power supply

Size – Should fit in your system caseConnectors – No. of connectors should be

moreWattage – Computers have rating between

300 – 350W and servers have rating 350 – 400W

More information:www.journeysystems.com/power_supply_calculator.php


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Practical

Perform the activity mentioned in Lab no. 1 in the text book:

• To install and uninstall a power supply unit in the system.

• Click on the image to run the video.


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SMPS Uninstall Video


Click on the image to run the video.

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Types of Cooling Systems - I

System produces heat while it is functioning that can damage the internal components of the system

Fans - System case and the system power supply have a fan in it that helps channel air flow in or out from the system case

Heat sink - Heat sink is used to cool the microprocessor and the other chips on the system


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Types of Cooling Systems - II

Thermal grease or heat sink compound - Thermal paste or heat sink compound is a fluid substance with grease properties.

Liquid submersion cooling - In this system, all the computer parts are submerged in a thermally conductive liquid. This liquid must have low electrical conductivity in order to make sure that, it will not interfere the normal operation of the computer components.


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Types of Cooling Systems - III

Liquid cooling system - Liquid cooling is a radiator for the CPU. Liquid cooling system circulates a liquid through a heat sink to the processor of the computer.

Heat is transferred from the processor to the cooler liquid. This hot liquid moves out to a radiator at the back of the case. The radiator transfers the heat to open air outside the case. The cooled liquid is then transferred back to the system and the process continues.


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What is a cooling system and list the different types of cooling systems?


Sl. Types of Cooling System

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Air Flow

Use an ATX form factor system - Due to the flow direction of the air from the ATX power supply unit, this form factor is preferred.

Use a large system case – A larger system case allows better flow of the air in the system.

Arrange the internal components – Each component should be placed approximately ¼ inches apart from each other.

Keep the system clean –This protects the system from air blocks due to dust.


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Practical


• To install a system case fan.


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Troubleshooting

Various tools can be used to troubleshoot SMPS problem

Due to a faulty power supply, the components of the system may also get damaged

Problem that may occur are:• Power Supply Fan does not Work or Emits a lot of

Sound

• Before Opening SMPS

• Troubleshooting PC problems without opening SMPS


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Practical


• To test the SMPS before opening.• Click on the image to run the video.


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Summary – I

Power supply unit supplies power to different system components

Power supply unit converts AC current to DC current Different form factors are PC/XT, AT, Baby AT, LPX,

ATX (NLX), SFX, and WTX Different components such as power connectors and

power supply fan Heat sink compound, liquid cooling system, liquid

submersion cooling, fans and heat sinks are different types of cooling system

Troubleshooting power supply problems is also an essential task for maintaining the system


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Explorative Work

Refer to Internet, reference books or magazine to get the information.

Do not copy the information provided in this text book. Consult your faculty for further guidance.


SMPS

Sl. Make WattageNo. of Molex connectors available

20/24 pin ATX Connector

Total no. of peripheral connectors

Approx. Cost

Year of Release

1

2

3

4

5

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Mind Map

Draw a mind map to summarize this chapter


power supply and cooling chapter 4 release 22/10/2010powered by dj

Documents

nlx power supply

power supplyaccepts

power supplymust

power socket

lot of power

power outlet

power supplypower supply

power supplyconverts