Session 3

Last Lesson• How Voltage, Current , and resistance are related• Ohms Law• Base units must be used• Power equation• Relationship between the Power and Ohms law• Electrical equipment is rated in Watts• The Power rating is referring to the output power not

input power

This LessonThis LessonIdentity circuit components represented by various drawing

symbolsConvert a basic circuit diagram into a wiring diagramConnect the components of a basic circuit and check that

the circuit operates correctly

SymbolsWhy do we use them instead of drawing the component?

See Australian Standard AS 1102.107:1997

Three types of diagrams commonly used are:

• Block Diagram• Circuit Diagram (schematic)• Wiring Diagram

Block Diagram

• Develop concept of operation or idea• How the individual circuit blocks are interconnected• Overview of circuit operation

Circuit DiagramsSchematics

Ladder diagrams • Vertical• Horizontal

Power Circuit for a star delta starter

Wiring Diagrams