Chapter · Electricity
Resistors
The part you reach for most, in the four arrangements that cover almost every circuit.
- 04Reading a resistor6 minFour coloured stripes, no numbers, and a part that looks identical to the one next to it. The code is quick to learn and quicker to forget, so this page is built to be used with a resistor in your hand rather than read once.
- 05Series and parallel7 minTwo resistors, two arrangements, two completely different circuits. One adds up the way you would expect and the other gets smaller as you add parts — which is the rule people refuse to believe until they watch it happen.
- 06Pull-up and pull-down8 minA digital input has to be held at a voltage to read as a 0 or a 1. Left unconnected it is held at nothing, and it will report both, changing as your hand moves nearby. A pull-up or pull-down resistor is the part that decides what the pin reads when nothing else is driving it.
- 07The voltage divider8 minTwo resistors in series and a wire taken from the middle. It is the most common circuit in electronics and the one people size wrongly most often, because the ratio sets the voltage and the size sets what it costs you.
Start at 04 and read down — the order is the order things get easier in. Or take the one with your part in it; every article stands on its own, and links back to whatever it needs.