Saturday, August 3, 2013

A Short Note About Circuit Diagrams & Symbols

                You probably already know that electrical engineers do not draw pictorial diagrams for every circuit.  Instead, they draw symbolic diagrams that represent a physical situation.  Do you remember this circuit?

Now, imagine that the element shown as a yellow rectangle is a battery.  We would draw this circuit as shown at the right.  Notice the symbol for the battery, with the "+" and "-" signs.  Notice also the two elements, shown here as rectangles.  Later, we will examine some symbols for particular elements.

        These diagrams may not look like the physical system, but they form a sort of language that allows precise communication between engineers about exactly what comprises a particular circuit.  Different kinds of electrical elements have different symbols.  Sometimes new symbols have to be invented when someone invents a new electrical device.

        Here are some symbols that are used for some common components.