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					A+ Essentials

Lesson 25


Learn about electronic components and how they work
Learn how to protect your computer system against damaging changes in electrical power

Mini Lesson

Basic electronic components in a PC include transistors, capacitors, diodes, ground, and
resistors. Materials used to make these and other electronic components can be:

      Conductors – materials that easily conducts (allows to pass through) electricity such as
       gold or copper.
      Insulators – materials that resist the flow of electricity, such as glass or ceramic
      Semiconductors – materials such as silicon whose ability to conduct electricity when a
       charge is applied falls between that of a conductor and an insulator.

A Transistor is an electronic device that can serve as a gate or switch for an electrical signal and
can amplify the flow of electricity. Invented in 1947, the transistor is made of 3 layers of
semiconductor materials.

A Capacitor is an electronic device that can hold an electrical charge for a period of time and
can smooth the uneven flow of electricity through a circuit. Capacitors maintain their charge
long after current is no longer present, which is why the inside of a power supply can be
dangerous even when it is unplugged.

A Diode is a semiconductor device that allows electricity flow in only one direction. A transistor
contains two diodes. One to four diodes used in various configurations can be used to convert
AC to DC. Singularly or collectively, these diodes are called a Rectifier.
A Resistor is an electronic device that limits the amount of current that can flow through it.

Protecting your computer system

      Make notes so you can backtrack
      Remove packing materials from work area
      Keep components away from hair and clothing
      Keep screws and spacers in an orderly place
      Don’t stack boards on top of each other
      Don’t touch chips on motherboard or expansion cards
      Don’t touch chip with magnetized screwdriver
      Don’t change DIP switch settings with a graphite pencil
      Have classroom instructor check your work before putting cover on and powering up
      Turn off a computer before moving it
      Keep disks away from magnetic fields, heat, and extreme cold
      Turn off power and unplug computer
      Always use a ground bracelet
      Never touch inside of a computer while it is turned on
      Never remove cover or put your hands inside monitor or power supply


What are Conductors, Insulators and Semiconductors?

What is a Transistor?

List 5 things that will help to protect your computer system.