# How to Draw a Wiring Diagram

Wiring diagrams, or circuit diagrams, are a tool that engineers and electricians use to represent circuits. The symbols on a wiring diagram are standardized so that everyone who looks at the circuit knows what a symbol represents. For example, an electrician in Seattle will be able to look at a diagram with straight lines drawn by an engineer in Florida and know that the straight lines mean wires. Simple circuit diagrams are easy to draw, once you know the basic rules.

1. Map out your circuit. Decide where you want the components of your circuit to be placed: wires, ammeters, voltmeters, resistors, switches, light bulbs, switches and capacitors.

2. Draw straight lines with your ruler to represent wires.

3. Draw an A inside a circle where any ammeters appear on your circuit or draw a V inside a circle for a voltmeter. Erase the straight line at this portion of the circuit (you do not want a straight line to run through your circle A or circle V because this would indicate--incorrectly--that the wire is continuous).

4. Draw zigzags on your circuit for resistors. The zigzag looks like three letter 'z's laying down and joined at the ends. Erase the straight line at this portion of the circuit and replace it with the zigzag.

5. To draw a switch symbol, erase a one-centimeter segment of line. Create a slide by redrawing the one-centimeter line: attach the line to the right-hand edge of the wire, dropping the line to the left at a forty-five degree angle downward. Draw a small circle with a tick above this sliding line (the small circle with a tick above looks a little like a light bulb).

6. Draw battery symbols on your circuit. The battery symbol is two parallel, horizontal line segments about one centimeter in length. Draw a shorter, thicker line segment between the two parallel lines, and another shorter, thicker segment immediately below. The battery symbol has a long bar on top (representing the positive terminal) and a short bar on the bottom (representing the negative terminal). You should erase a line segment when inserting the battery symbol.

7. Erase a two-millimeter line for a capacitor symbol. In the gap, draw two one-centimeter, parallel vertical lines on either side of the gap.

8. Draw a light bulb by erasing a one-centimeter line segment and drawing a circle in the gap. One third of the way down the circle, draw a horizontal line with a small letter "o" under the line (draw in one continuous line as if you are writing in cursive).

## Warning

• Double-check your diagram before using it to build a circuit; an incorrectly drawn circuit diagram will lead to an incorrectly built circuit.