[ we make science jokes, periodically ]

Resistors: What are They?

Check out this picture. How many rectangular blue and green components can you spot?


Those are resistors! Resistors usually are used to resist the flow of electric current.

Pop quiz! Can you name the basic properties of electricity? If you answered voltage, current and resistance, you were right!

Let's talk about current. A simple definition for current is how much electricity is flowing. It has its measurement called an Ampere, but that’s for another time. Let's say some current flows from a battery to a LED.

LEDs are fragile. They are so fragile that they are easy to break if too much current flows through them. What if our battery provides too much current to directly connect to our LED. What can we do to get it to work? A RESISTOR!

As the current flows through a resistor it will lower the current to a safe level for the LED. How does it do this? Well, by wasting energy. It burns energy by turning the current into heat; that’s why electronics tend to get hot when turned on: All those little resistors are heating up.

Let’s add one more thing to our resistor talk: Resistors come with different values called Ohms. An Ohm is a measure of resistance. A value of 1 Ohm would be really low and do very little to reduce current, but a 100,000 Ohm resistor would drop current significantly. If we put our 1 Ohm resistor in our LED example, it might still break our LED since it didn’t lower the current by much, while the 100,000 Ohm resistor might drop it so much that our LED won't even turn on. Like Goldilocks, sometimes you need to find the one that is just right for what you need.

That was one example of what resistors do, and maybe the most common one. Like anything, resistors and how to use them can get complicated.