Schematics and Electrical Components
“A circuit diagram (also known as an electrical diagram, wiring diagram, elementary diagram, or electronicschematic) is a simplified conventional pictorial representation of an electrical circuit. It shows the components of the circuit as simplified standard symbols, and the power and signal connections between the devices. Arrangement of the components interconnections on the diagram does not correspond to their physical locations in the finished device.
Unlike a block diagram or layout diagram, a circuit diagram shows the actual wire connections being used. The diagram does not show the physical arrangement of components. A drawing meant to depict what the physical arrangement of the wires and the components they connect is called “artwork” or “layout” or the “physical design.”
Circuit diagrams are used for the design (circuit design), construction (such as PCB layout), and maintenance of electrical and electronic equipment.” Taken from the Wikipedia.
Without being able to read and understand a circuit diagram your not going to get very far in physical computing. Fortunately in this class will be dealing with a very limited set of electrical components. The one’s that you’ll need to use for this class are the following:
I found this very handy little set of Electronic symbols that can be used in Illustrator. It’s very useful for when you create your own schematics. You can find it here:http://blog.flashicon.com/?p=104
ITP’s physical computing page has a very nice description of the most common electrical components and their symbols so I’m not going to recreate it here. Instead open up the following link to read more.
http://www.tigoe.net/pcomp/code/understanding-electricity
http://en.wikipedia.org/wiki/Electronic_symbol
One of the common mistakes when reading schematic is to assume that the physical arrangement of parts on the board will be the same as the schematic. Remember a circuit diagram just shows connection between the devices not their physical arrangement.
Here are some more links the Wikipedia’s definitions for the electrical components that will be using:
Resistor
http://en.wikipedia.org/wiki/Resistor
http://www.sonofsofaman.com/hobbies/electronics/reference/resistorcalculator.asp
Capacitor
http://en.wikipedia.org/wiki/Capacitor
Diode
http://en.wikipedia.org/wiki/Diode
Transistors
http://en.wikipedia.org/wiki/NPN_transistor#NPN
