Electronics



Electronics are here to stay! I bet you can think of a lot of things that are electronic such as computers, mobile phones, DVD players and games consoles. Grocery stores, hospitals, airports and schools are full of electronic devices. **VIDEO/PPT/IMAGES** What makes a device electronic? It is not just because it uses electricity!!! It is only electronic if certain electronic components are used to control the movement of electricity through electronic circuits. Electronics is the study of how small electric currents are controlled to make all kinds of electronic and electrical equipment work. Understanding electronics and how electronic devices work may seem daunting but by breaking electronic devices down into simple system or block diagrams and considering the **Input, Process, and Output** we can begin to understand how these devices work, and by taking a closer look at the components used, and their function can we begin to understand how the electronic world around us works. **TASK What would we do without electricity? SCRIBD** At this point you might be asking yourself what is electricity?
 * What are electronics?**

media type="custom" key="678683" **Current** Electric current is the movement of tiny particles, called electrons along a piece of wire. All substances contain **electrons**, they are part of the atoms which things are made... you, the desk, this computer... EVERYTHING!  When electrons move, they carry electrical energy from one place to another. A lightning bolt is one example of an electric current, although it does not last very long. Electric currents are also involved in powering all the electrical appliances that you use, from a washing machine to flashlights and from telephones to MP3 players. These electric currents last much longer.  In certain substances, e.g. metal wire, electrons can be made to move easily by applying a power supply. Substances in which electrons move easily are called conductors. When we use electricity we need to be able to measure the amount of current. Just like with weight and length we need a unit to help us describe how much current there is. We call the units for measuring electric current **Ampers** or **Amps**. We write the unit as a letter **A**. **TASK Which Units?**
 * Voltage**

Power** Ohm's Law defines the relationships between (P) power, (E) voltage, (I) current, and (R) resistance. One ohm is the resistance value through which one volt will maintain a current of one ampere.
 * Resistance

( I ) [|Current] is what flows on a wire or conductor like water flowing down a river. Current flows from negative to positive on the surface of a conductor. Current is measured in (A) amperes or amps.
 * Recap**

( E ) [|Voltage] is the difference in electrical potential between two points in a circuit. It's the push or pressure behind current flow through a circuit, and is measured in (V) volts.

( R ) [|Resistance] determines how much current will flow through a component. [|Resistors] are used to control voltage and current levels. A very high resistance allows a small amount of current to flow. A very low resistance allows a large amount of current to flow. Resistance is measured in ohms.

( P ) [|Power] is the amount of current times the voltage level at a given point measured in wattage or watts.

Examples of some of the electronic components you will become familiar with: media type="custom" key="722311"