Special Notes: Potentiometer

755

20

2

For my loyal followers and learning viewers, hold on while I make the next lesson. In the mean time, enjoy this extra from my third lesson, adding a few things to your list of knowledge about the potentiometer. For those unfamiliar with this series all together, watch the previous lessons now! And now special note on potentiometers.

Step 1: Minimize the Connections

For those who saw my previous lesson, I described the way that you would connect a potentiometer to a battery would be to take its middle pin, called the input, and attach it to the ground. Power would be connected to the power as usual, and the ground terminal (not connected to LED) would as well go to ground. Here is where I would like to make a repeal. Remember, being that potentiometers follow a sensor design, this would technically be the proper format for constructing the circuit. But in this particular case, you do not need to connect the ground terminal to the battery's ground, being that technically, the input wire already connects to the ground.

Do not worry if you followed my previous design, either way, the circuit will work! I myself have confirmed this. But remember, this is for this specific kind of case alone. When directly hooking up any variable resistor (or 'sensor') to a power source and connecting its input to an out put device (like the LED shown in the circuit), you do not, I repeat, do not, have to connect the sensor's ground terminal to ground!

I hope you enjoyed this special note. Keep on watching and keep on learning. See you in lesson 4!

Recommendations

• 3D CAM and CNC Class

1,587 Enrolled

2 Discussions

A problem with this circuit is that if the pot is turned all the way "up" it will likely burn out the LED. Also if turned all the way "down" the LED may still be too bright.

Just some notes:
A pot can be connected as a variable resistor or a variable voltage divider, one needs 2 terminals, one three.
That is what is going on here, a variable resistor.
Second the better name of the middle connection is the wiper. See: Potentiometer - Wikipedia
https://en.wikipedia.org/wiki/Potentiometer. Input is bad since it is often used more like an output.