With Level B releasing in a few weeks, here’s a preview of yet another electrical component you will learn to work with.
Remember in Level A when you learned to work with resistors to moderate the flow of current? The resistors you were using had a set value, or a set amount of current they would allow to flow through the circuit. Now what if you needed to adjust the amount of current up or down based on the needs of the circuit? A potentiometer is a variable resistor. It allows the current flow to be adjusted using a dial.
An adjustable resistor is very useful for something like volume control or anywhere you need to fine tune the exact level of resistance needed for a piece of equipment.
In this project, we’ve set up the same basic monitoring system as we used for the phototransistor project (link): the analog-to-digital converter is keeping an eye on the voltage flowing through the potentiometer. The difference here though is that based on the voltage flowing, instead of just turning the LED on or off, we are using pulse width modulation to drive the LED. This allows us to control the brightness from fully off to fully on, to anywhere in between.
Sound like fun? Good news! Potentiometers, phototransistors, analog-to-digital signal conversion, and pulse width modulation are all covered in Level B. Think of all the amazing projects you’ll be able to do with these new skills!