1. Electrical Engineering
Technological World
Chapter 14

2. Electronics vs. Electricity
Electrical Appliances (ex: toasters) and Electronic Devices (ex: cell phones) depend on electrical currents.
Electronics
Electricity
Made of SEMICONDUCTORS (usually silicon)
Made of CONDUCTORS- metals and alloys (copper)
MINIATURE, LOW-INTENSITY currents
POWERFUL currents
Conduction is finely controlled  they can process information
Conduction is not as finely controlled

3. Electrical Circuits Conventional Current Flow:
From + to – terminal on the power supply (battery)
Electron flow:
FROM – TO + terminal on the power supply

4. Direct Electric Currents
Electrical currents are caused by the movement of electrons.
DC happens when electrons move
in 1 direction within a circuit.
Anything requiring a battery
works on a direct current.
Electronics use direct currents
as well.

5. Alternating Electric Currents
Electrons within the circuit move in a back and forth direction. The electricity we get from Hydro Quebec is an example of alternating electric currents.

6. Why use AC instead of DC? AC is much less expensive than DC!
Less space is required
More reliable