1. Electrical Principles 1 - 7793A, Applied Electricity 1 - 7793AV Mt Druitt College of TAFE Dept. Electrical Engineering

2. © Mike Stacey 20082 Assessment Theory Test 1: 25% Theory Test 2: 50% Practical: 25%  May consist of 2 separate tests

3. © Mike Stacey 20083 How to pass the subject – your responsibility Access the web site at http://wsiee.wikispaces.com/ every couple of days for: http://wsiee.wikispaces.com/  Weekly notes – powerpoint slides in *.ppt and *.pdf format:  Print the pdf versions and bring to class BEFORE each class.  Other material such as revision questions for tests and related material  It can all be found on a page dedicated to each week of the subject. You should print this page also.  Store all hard copies in a folder and stay organised!

4. © Mike Stacey 20084 Web site – home page

5. © Mike Stacey 20085 Web site – class notes index

6. © Mike Stacey 20086 Web site – Compulsory Core index

7. © Mike Stacey 20087 What you require The workbook: Student Workbook available from the college bookstore: "Electrical Principles for Advanced Diploma Courses, Workbook 1" Text: (Recommended) Phillips, Peter 1996, Electrical Principles 1 ISBN 0 170092127 Thomas Nelsen, Melbourne, Victoria. Weekly notes downloaded and printed from the website A Calculator: Capable of performing rectangular -> polar conversions, logs, trig, base N number systems. Folder to store weekly material and pens and paper

8. © Mike Stacey 20088 Topics Basic Electrical Concepts Ohm's Law Power Series Circuits Parallel Circuits Series - Parallel Circuits Voltage Sources Effects of a Current Electrical Measurement Resistance Practical Resistors Sources of electrical energy

9. © Mike Stacey 20089 Today’s Topics See workbook pages 2.1 - 2.6  The Atom  Potential difference, current, resistance  Source of electricity  Circuit diagrams  Current direction  Current effects  SAFETY  Maths review  Homework: Complete Tutorial 1 (P 2.8) and Safety Tutorial (P2.7) for next week

10. © Mike Stacey 200810 The Planetory Atom (ref P2.1) An atom consists of a central nucleus surrounded by orbiting electrons. Electrons are negatively charged and protons positively charged, Figure 1

11. © Mike Stacey 200811 Potential Difference, Current and Resistance (ref P2.1) A potential difference exists between negatively charged and positively charged bodies. Resistance is the ability of a material to oppose the flow of electrons. Figure 2

12. © Mike Stacey 200812 Water Analogy for Current Flow [1] A water-pressure difference causes a current of water to flow between the two tanks. The thick pipe passes a larger current than the thin pipe. Figure 3

13. © Mike Stacey 200813 Water Analogy for Current Flow [2] Figure 3

14. © Mike Stacey 200814 Basic Sources of Electricity (ref P2.2) Zinc-carbon voltage cell Chemical action removes electrons from the carbon. Carbon rod is then positively charged. Electrons accumulate in the zinc hence it is negatively charged. There is a potential difference, or voltage, between the +ve and –ve terminals. Figure 4

15. © Mike Stacey 200815 Basic Electric Circuit (ref P2.2) Switch open: no conduction path between battery terminals. No current flow. Switch closed: potential difference between battery terminals causes a current to flow from negative terminal, through the lamp and switch, to the positive battery terminal. Result: the lamp lights up. Figure 5

16. © Mike Stacey 200816 Circuit Diagrams (ref P2.2) Figure 6

17. © Mike Stacey 200817 Current Direction (ref P2.3) & Effects of Electric Current Current Flow  Conventional Current direction: Positive to Negative  Direction of Electron Flow: Negative to Positive Effect of electric current  Heat  Magnetic field  Chemical effects  Muscle contraction

18. © Mike Stacey 200818 Conditions Required for Current Flow (ref P2.3) Source of EMF Conducting path