ABSTRACT
This chapter explains the main differences between an electric schematic diagram and a corresponding wiring diagram. It describes recognise a schematic diagram and explores identify common IEC circuit symbols. The chapter also describes recognise a wiring diagram and provides recognise a block diagram. It also explains recognise a single-line diagram. A ladder diagram is simply a type of schematic diagram in which the voltage supply is represented by two vertical lines, between which the circuit components are connected rather like the 'rungs' of a ladder – hence the name. A wiring diagram is a somewhat-simplified representation of how a circuit actually looks. Wiring diagrams can be relatively simple or very complicated indeed but, in either case, they are not intended to help us to understand how a circuit actually works; that is not their primary purpose. Block diagrams, as the name suggests, use labelled rectangles to represent the principal parts of a complex circuit.
