# Potentiometer as a voltage divider

SCHEMATIC DIAGRAM

ILLUSTRATION

INSTRUCTIONS
Begin this experiment with the pencil “lead” circuit. Pencils use a rod made of a graphite-clay mixture, not lead (the metal), to make black marks on paper. Graphite, being a mediocre electrical conductor, acts as a resistor connected across the battery by the two alligator-clip jumper wires. Connect the voltmeter as shown and touch the red test probe to the graphite rod. Move the red probe along the length of the rod and notice the voltmeter’s indication change. What probe position gives the greatest voltage indication?
Essentially, the rod acts as a pair of resistors, the ratio between the two resistances established by the position of the red test probe along the rod’s length:

Now, change the voltmeter connection to the circuit so as to measure voltage across the “upper resistor” of the pencil lead, like this:

Move the black test probe position along the length of the rod, noting the voltmeter indication. Which position gives the greatest voltage drop for the meter to measure? Does this differ from the previous arrangement? Why?
Manufactured potentiometers enclose a resistive strip insid a metal or plastic housing, and provide some kind of mechanism for moving a “wiper” across the length of that resistive strip. Here is an illustration of a rotary potentiometer’s construction:

Some rotary potentiometers have a spiral resistive strip, and a wiper that moves axially as it rotates, so as to require multiple turns of the shaft to drive the wiper from one end of the potentiometer’s range to the other. Multi-turn potentiometers are used in applications where precise setting is important.
Linear potentiometers also contain a resistive strip, the only difference being the wiper’s direction of travel. Some linear potentiometers use a slide mechanism to move the wiper, while others a screw, to facilitate multiple-turn operation:

It should be noted that not all linear potentiometers have the same pin assignments. On some, the middle pin is the wiper.
Set up a circuit using a manufactured potentiometer, not the “home-made” one made from a pencil lead. You may use any form of construction that is convenient.
Measure battery voltage while powering the potentiometer, and make note of this voltage figure on paper. Measure voltage between the wiper and the potentiometer end connected to the negative (-) side of the battery. Adjust the potentiometer mechanism until the voltmeter registers exactly 1/3 of total voltage. For a 6-volt battery, this will be approximately 2 volts.
Now, connect two batteries in a series-aiding configuration, to provide approximately 12 volts across the potentiometer. Measure the total battery voltage, and then measure the voltage between the same two points on the potentiometer (wiper and negative side). Divide the potentiometer’s measured output voltage by the measured total voltage. The quotient should be 1/3, the same voltage division ratio as was set previously:

3. Potentiometer – Wikipedia, the free encyclopedia
4. Voltage divider – Wikipedia, the free encyclopedia
5. Potentiometer
6. Voltage Dividers
7. Voltage divider with 10kΩ potentiometer
8. Potentiometer/voltage divider?!??
9. 1 Voltage Divider / Potentiometer
10. Potentiometer-Based Position Transducer Voltage Divider and Power …
11. Voltage divider – loaded and open-circuit dB calculator damping …
13. voltage divider: Definition from Answers.com
14. activity_2
15. TONE CONTROL ARRANGEMENT WITH VOLTAGE DIVIDER; POTENTIOMETER AND …
16. Potentiometer with digital display – Patent 4247816
17. voltage divider (potential divider; potentiometer) – (potential …
18. Voltage Dividers and Attenuators
19. Arduino Lab 1 – The Voltage Divider
20. Testing of voltage dividers by means of a double potentiometer
21. Using the R345 potentiometer as a voltage calibrator
22. Potentiometer-Based Position Transducer Voltage Divider and Power …
23. Potentiometer Calculator, Voltage Divider Calculation – Physics …
24. Dekapot Decade Potentiometers. DP1211 Voltage Divider.
25. Voltage Divider. DP1311 Voltage Divider. Precision voltage divider …
26. VOLTAGE-DIVIDER CIRCUITS
27. PH 292, General Physics Laboratory II, Spring 2003
28. Voltage Dividers and Voltage References Information on GlobalSpec
29. Data sheet for Digital Potentiometer Voltage Divider — KVD-500 …
30. Make: Online : Ask MAKE: Voltage divider
31. Basic electric circuit theory, electricity
32. Voltage Divider Design Considerations
33. SGC Voltage Divider Information
34. Model 8000A/8001A MODEL INFORMATION Automated Potentiometer Binary …
35. Design a Voltage Divider — from Wolfram Library Archive
36. Experiment_ Voltage divider
37. Phys 15b: Lab 2: I-V Curves; Voltage Dividers 1 Purpose
38. YouTube – Circuit Analysis Application – Voltage Divider (Part 3 …
39. Kelvin Varley Voltage Divider KVD-500
40. voltage divider – offers from voltage divider manufacturers …
41. INTRODUCTION TO ELECTRONICS
42. USER MANUAL FOR VOLTAGE DIVIDER
43. Voltage Dividers and Electronics
44. Sensor Design
45. JW-10 TRANSISTOR BIASING Voltage divider (dc) biasing • There are …
46. Rotary Transducer, Crack Displacement Sensor, Voltage Divider …
47. How to Calculate the Wiper Voltage of a Digital Potentiometer – Maxim
49. Voltage divider circuits This worksheet and all related files are …
50. Circuit Analysis – Voltage Divider Equation or Formula (Part 3 …
51. voltage divider – definition of voltage divider by the Free Online …
52. IC VOLTAGE DIVIDER PGA 10-UMAX – MAX5431AEUB+
53. voltage divider – FREE voltage divider information | Encyclopedia …
54. Arduino Forum – Replacing a Potentiometer with a voltage divider
55. Lab5
56. Voltage divider circuits This worksheet and all related files
57. How do you make a simple circuit using a potentiometer, photo cell …
58. Step-Up DC-DC Converter Calibration and Adjustment Using a Digital …
59. Project 011 – keywoniki
60. Potential Divider and Potentiometer – Electronics Tutorials
61. Potentiometer Resistance Voltage Circuit Pot Wire Cell
62. HIGH PRECISION POTENTIOMETER VOLTAGE DIVIDER DEKAPOT – eBay (item …
63. voltage divider@Everything2.com
64. Laboratory Exercise 1 – Voltage Dividers
65. Potentiometer | Define Potentiometer at Dictionary.com
66. Physics: Electrical circuits, variable resistor, voltage divider
67. Article: Mini metrology lab. (Kelvin-Varley voltage divider …
68. Electronics Workshop for Artists
69. Using ADCIN or POT/RCTIME? [Archive] – MEL PICBASIC Forum
70. Voltage Divider Lab
71. 4.5 Resistance to Voltage
72. Digital Potentiometers Convert Voltage To Resistance
73. Potentiometer as a rheostat
74. voltage divider calculation
75. ELE427 – Lab 1 Potentiometers and Optical Encoders
76. Trimmer potentiometer
77. StateMaster – Encyclopedia: Voltage divider
78. What is a Potentiometer Used For?
79. Voltage Dividers
80. Laboratory 2 More Resistor Networks and Potentiometers.
81. The Digital Multimeter – Calibration of a Linear Motion Potentiometer
82. 1 Hands-on Lab LabVIEW – NI-DAQ Analog Input and Output Concept 1 …
83. UaShem.com | Electronics guide | Measuring current and voltage …
84. Patent-Invent: Potentiometer
85. protolab / TutorialSensors
86. John Caunt Scientific
87. Potentiometer Model
88. Robot Room – Analog Light Sensor Comparator
89. ELEC 241 Lab – Experiment 3.1
90. bases, voltage dividers, preamplifiers
91. TechOnline | A Primer on Digitally Controlled Potentiometers
92. HX Series – Linear Potentiometer, Position Transducer …
93. Search www.Firstmarkcontrols.com for ‘voltage’
94. Alternative voltage reference? | Sci.Electronics.Basics …
95. Voltage divider rule definition of Voltage divider rule in the …
96. Potentiometers
97. The Secret Life of Pots
98. The Potentiometer—[The Physics Teacher 43, 232 (2005)]
99. SparkFun Electronics • View topic – Determining Correct Value of …
100. Membrane Potentiometers Simplify Position Sensing

COMMENT technologies

1. Anonymous

Digi-Key has recently updated the structure of our URLs and have noticed that you are currently linking to an old URL. The URL is located on the following pages (./potentiometer-as-a-voltage-divider]. Could you please update the link on your page from the following: [http://parts.digikey.com/1/parts/1346162-ic-voltage-divider-pga-10-umax-max5431aeub.html] to: [http://search.digikey.com/scripts/DkSearch/dksus.dll?lang=en&site=us&KeyWords=MAX5431AEUB%2B-ND]?
If you have any questions or concerns, please feel free to contact me. We appreciate your assistance.
Best regards,
Diane Gonsorowski
http://www.digikey.comdiane.gonsorowski@digikey.com
701 Brooks Ave S, Thief River Falls, MN 56701
Phone: 800-338-4105 ext. [1016]

2. Anonymous

Digi-Key has recently updated the structure of our URLs and have noticed that you are currently linking to an old URL. The URL is located on the following pages (./potentiometer-as-a-voltage-divider]. Could you please update the link on your page from the following: [http://parts.digikey.com/1/parts/1346162-ic-voltage-divider-pga-10-umax-max5431aeub.html] to: [http://search.digikey.com/scripts/DkSearch/dksus.dll?lang=en&site=us&KeyWords=MAX5431AEUB%2B-ND]?
If you have any questions or concerns, please feel free to contact me. We appreciate your assistance.
Best regards,
Diane Gonsorowski
http://www.digikey.comdiane.gonsorowski@digikey.com
701 Brooks Ave S, Thief River Falls, MN 56701
Phone: 800-338-4105 ext. [1016]