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Hello and Welcome

This Instructable is going to be short and sweet. I would like to share with you the power of potentiometers. A simple component that can be used as a voltage divider. You may be saying to yourself, "Duh, everyone knows that!" Well, unfortunately, this simple concept escaped many of my classmates even after a year of schooling. So, I decided to take this opportunity to help clear up any confusion you may have.

I hope you find this Instructable informational and remember inspiration can be found anywhere!

Thank you for viewing!

Step 1: What Is a Potentiometer?

A potentiometer is an adjustable resistor which consists of a wiper that slides across a resistive strip to deliver an increase or decrease in resistance. The level of resistance will determine output of current to the circuit.

However, the potentiometer can be used as a voltage divider!

This is exactly what we are going to do today.

Step 2: Component List

To build the voltage divider, as shown in the circuit, you will need the following parts:

1 x 5 volt power supply

1 x 10K Potentiometer

1 x 1K resistor

1 x RED LED

1 x Digital Volt Meter

1 x Breadboard for prototyping

Wires cut to varying lengths (clean and organized prototyping is a good habit to have)

Cables - for measuring Voltage

If you do not have a 5 volt power supply I have made an Instructable showing how to build your own variable voltage supply.

How to fabricate a lunch box into a dual 0-12VDC power supply - LINK

Step 3: Building the Voltage Divider

1.) Begin by bringing power onto the board.

2.) Set up the Voltage Divider. Remember to GROUND the potentiometer.

Forgetting to ground the POT seems to be the common mistake.

3.) Place the LED and current limiting resistor on the board.

Basic Red LEDs -

This is a very basic 5mm LED with a red lens. It has a typical forward voltage of 2.0V and a

rated forward current of 20mA.

Features:

1.8-2.2VDC forward drop

Max current: 20mA

Suggested using

current: 16-18mA

Luminous Intensity: 150-200mcd

Step 4: Results

Congratulations!

You have successfully constructed a circuit that gives you a variable 0-5VDC.

Some Technical Stuff:

The recommended current rating for the LED is 16 - 18 mA. Since I am using a 1K resistor in series with the LED my max current will never exceed 5 mA. I used a 1K resistor because I have an abundance. If you wanted to get the current closer to the recommended levels simply use OHM's law and calculate the resistor size.

If you would like to learn more there are many knowledgeable users on Instructables.com

Here are some links to help guide you:

All about OHM and his LAW - LINK

Ohm's law - LINK

Step 5: Gratitude

Thank you all for viewing my Instructable.

I hope it was educational and you found it useful.

<p>I have a 240vAC to 12v DC power pack which has a reading of 17.7 v DC output with no load. I intend to use it as a 12v DC supply to power signals on a model railway. The signals are red &amp; green LEDs with suitable resistors. I know the output on the power packs are sometimes higher than specified on the pack label. Would this circuit be suitable for my purpose to control the output to 12v DC?</p><p>Thanks</p>
<p>ty , Helped alot</p>
<p>Very good tutorial, thank you for sharing :)</p>
<p>Thank you!!! Wanted to change speaker output to a line output but didn't know how. Looked up on google then on here... just what i needed. :)</p>
Nice job
Thank the gods! This is exactly what I needed for a modding project I am working on.<br>It's just like I phoned you up and said &quot; how do I do this?&quot;<br>Cheers bud, nice one!
I'm glad you found this helpful. I hope to see your project on Instructables.com
thanks for this instructable!<br>just wanted to point out that the main purpose of potentiometers is actually to use it as a voltage divider since its value is not so accurate<br>

About This Instructable

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Bio: My short attention span lends well to an ever changing industry. I love dedicating all my energy into a project and the satisfaction of a ... More »
More by bweaver6:How to use a potentiometer as a voltage divider. How to fabricate a lunch box into a dual 0-12VDC power supply. 74HC595 Shift Register Demystified  
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