The mighty resistor
A small striped tube whose only job is to slow electrons down.
Read first: Resistance
A resistor is the most common part in any circuit. It looks like a tiny tube with two metal legs and a few coloured stripes painted on the side.
Reading the rainbow
Those stripes are a colour code that tells you exactly how much resistance the part has. You only need to know four colours to start:
Brown = 1, Red = 2, Orange = 3, Yellow = 4. The first two stripes make a number, the third stripe is how many zeroes go after it. The gold stripe at the end means "this is the right end to read from".
Why does an LED need a resistor friend? Because an LED on its own would gulp down all the current the battery can give it — and burn out in a flash. The resistor sits in the loop and only lets a safe amount through.
Now you understand…
- Resistors squeeze the current down to a safe amount.
- Coloured stripes spell out the value.
- Always pair a resistor with an LED.
Time to meet the part the resistor is protecting.