We'll finish up by introducing another part that's in your kit bag. This is the potentiometer (sometimes also called a pot because the word potentiometer is just terribly long)
Recall oh so many hours ago, when we talked about having a magic resistor that we could change from 0 ohms to infinite ohms and used that to think of how resistance changed LED brightness? Well, that isn't such an imaginary thing after all, in fact they are quite common. Potentiometers are resistor that are adjustable with a knob. We will talk about potentiometers more in detail in a future tutorial so consider this a light introduction!
The resistance between the two outer pins is always the same. The resistance between the middle pin and the left or right pin changes!
Note that we are connecting to the wiper and one end, not to both ends. Also, we have a 100 ohm resistor between the potentiometer and the LED.
Please try to build this circuit, verify that the LED dims and brightens when the potentiometer is turned.
The 100 ohms gets added to the resistance of the potentiometer!
If connecting the 100 ohm resistor like in the diagram means the resistances are added, what is the total resistance when the 10K potentiometer is turned all the way 'down'?
Last Quick Quiz!