Assignment # 3

The theory of electricity: a general term referring to a variety if phenomena resulting from the presence and flow of electric charge.
Conductor: any material that easily permits the flow of electric current.
Insulator: an object that supports or separates electrical conductors without passing current through itself.
Voltage: the difference of electrical potential between two points of an electrical / electronic circuit.

The two voltages most commonly used by computer components are 120V and 230V.

Current: the flow (movement) of electric charge.
1-10-100 Rule: the cost to fix a defect increases exponentially the later it is identified.

You can calculate the amount of current running through a current by either using an ammeter or using the formula
I=V/R (Current = voltage/ resistance)

AC and DC: Alternating current (AC) is an electrical current whose magnitude and direction vary, while direct current (DC) stays constant.
Electric Power: the rate at which electrical energy is transferred.
Resistance: a measure of the degree of which an object opposes an electric current through it.
Impedance: like resistance except it occurs with alternating current.

Human Body's Resistance Capability is 0.1 A before it becomes fatal.

5 Safety Precautions You Can Take To Avoid Electric Shock: Make sure equipment is turned off
before moving, make sure equipment is well grounded, make sure tools are well insulated, make sure all electrical equipment covers are secured when your not working with it, and make sure you’re well grounded.

Static Electricity: is the build-up of electrons on an object. It is dangerous to humans as enough of it can cause a heart attack, while computers can be wiped by a static jump.

To avoid static build-up you should don’t wear wool, don’t drag your feet while walking on carpet, don’t wear rubber shoes, use dryer sheets, and keep the air in your house humid.

To avoid static discharge you should keep hands well moisturised, wear leather shoes, tap metal surfaces with knuckles versus using your fingers, wear a metal thimble (keeping it contact with your skin at all times), and/or carry a coin to touch metal surfaces with first.

Two things that are found in the ESD- prevention kit are a grounding wire strap and a rubber mat.

The job of the PC power supply is to convert AC power into DC power sop the computer can use it.

Specific Power Supply Requirements
For a motherboard: 240V-300V
For memory chips: use 5-10 watts
For a CPU: 45 watts
For a hard drive: 1 amp of 12 Volts
For a CD-ROM drive: 360 watts
For a floppy drive: 10-20 watts

The motherboard is the component that the power light goes on when it gets power. Without this the computer couldn’t run.

Molex connectors supply power to hard drive, Berg connectors supply power to floppy disk drives, and an ATA power connector connects power from the power supply to the serial connectors in the computer.








Bibliography

http://blog.softwareprojects.org/the-110100-rule-6.html
http://computer.howstuffworks.com/power-supply.htm
http://en.wikipedia.org/wiki/Alternating_current
http://en.wikipedia.org/wiki/Conductor
http://en.wikipedia.org/wiki/Electrical_resistance
http://en.wikipedia.org/wiki/Electric_current
http://en.wikipedia.org/wiki/Electric_power
http://en.wikipedia.org/wiki/Electricity
http://en.wikipedia.org/wiki/Insulator
http://en.wikipedia.org/wiki/Power_supply
http://www.bbc.co.uk/dna/h2g2/A6378744
http://www.newton.dep.anl.gov/askasci/phy00/phy00367.htm
http://www.ptub.com/content /et/14086/css/14086_35.htm