Resistors are a fundamental component in electronics and we will see them in almost every circuit we build. They come in a wide variety of flavours ( as you will soon see) and your kit includes a number of examples.
What is resistance?
Broadly speaking all materials can be categorized as conductors or resistors according to their ability to let electrical current flow. Resistors are those materials — or components — in a circuit that inhibit or resist the flow of electrons.
Resistance is the measure of opposition to current flow. Its unit is Ohms and we represent resistance with the greek letter omega (Ω).
What do Resistors Want?
Resistors are placed in circuits to protect other components (they do other stuff but that will get us started). They are important because all of the components in our kit have electrical limits (including resistors). If you exceed the limits you can damage components.
Resistor Representations
Through out this course you will see resistors represented in photos, diagrams and schematics. There are two primary schematic representations for fixed resistors — i tend to use the zigzag one — some software packages use the rectangle.
Note that the specific value ( 1KΩ or 47kΩ) of the resistor is also given beside the resistor symbol. The R1 and R2 labels are tied to parts lists — they are not usually included in hand drawn circuits. I will leave them out most of the time.
Identifying Fixed Resistors
When starting out, one major skill you need to develop is resistor identification. Identification has to do with determining the size of a resistor. Where resistor size refers to the amount of resistance, not the size of the physical package. In fact, you should notice as you work your way through this Building Block that all of our resistors are the same size physically. But the resistances they provide differ by several orders of magnitude.
We determine resistor size by decoding the color bands on their bodies. The video below will explain the process.
Required Parts
You will need your fixed resistors, your resistor color chart and the resistor worksheet from your kit. OH — you also need your crayons! (I don’t have a crayon pic yet.)
