Introduction: Paper Resistor

A simple technique to make a variable resistor from paper and pencil.

Step 1: List of Materials Required:

All the things required to make this resistor are readily available in homes and
you will not require to spend any money to buy them.
The materials required are as follows:
(1) A thick (rather stiff) sheet of paper.
(2) A HB pencil.(preferably 3B,4B or 6B)
(3) A ruler or scale.
(4) Few metal paper clips.(will be used as the pins of the resistor)
(5) A multimeter or ohm meter to measure the resistance and calibrate your
resistor.
(6) pair of scissors.

Step 2: Lets Make It !!!

Building this resistor will hardly take an hour.You can build it in just 5 steps.
Step (1):
SubSteps:
(1)First take the sheet of paper(as i have told before it should be stiff and rough).
(2)Cut a small strip out of it.(as I have shown in the picture).

Step 3: Start Scribbling !!!!

Now take out the heck out of the pencil ! This is was is the second step.
Step (2)
Substeps:
(1) Take a scale/ruler and your HB pencil and place the ruler near one side(the lenght i.e. the longer side) of the strip at about 0.5cm.
(2) Draw a demarker line with the ruler
(3) Now rub and scribble your pencil in the demarked area (as hard as you can !!).

*It is better if you scribble in a linear way ,horizontally and carefully seeing that no space is left blank in that area.

*If you use here a thin paper then it will tear off so I again recommend to use a stiff paper.

Step 4: Time to Work Seriously!!

This is the most important part of this instructable - THE CALIBRATION PART.
Before starting with this part,
PLEASE MAKE SURE THAT:
  • the area beyond the demarked one (where we have scribbled) is clean as while scribbling you have may have touched the other part of the paper,so rub off the ajoining area with an eraser-neatly!
*make sure that your multimeter is working and set your multimeter to to the resistance range of 200K ohms.

Step (3):
Substeps:
(1) Put the clip to the starting point of your strip(i.e. on the most lefthand side).
(2) See to it that the clip is firmly put (as shown in the figure)
(3) Next to this clip, put another clip ,leaving a space of around 1/2 to 1 cm.
(4) Connect your multimeter probes to the clip and check the resistnance.
(5) Adjust the position of the second clip to get the desired resistance.
(6) After getting the desired resistance ,see that the clip is frimly stuck.
(7) I have made actually here a variable capacitor like taht used in a light dimmer , so you can see in the photo that i have stuck two clips as the other pin of the resistor . The clips as so calibrated that the resistance difference between two clips is of 10 k ohms.You can calibrate many clips side by side with specific resistance interval and can make your own light dimmer !!

Step 5: Limitations,Experimentation and Applications -

Though this resistor is modest at perfromance it can't be used for all practical applications.This is because it is difficult to calibrate this resistor to lower resistance value in ohms.Also while making a PCB it would be difficult to attach it.But for experimental purposes it is good.You can learn a lot about resistors by this instructable.The pencil lead is actually a graphite rod (carbon).By rubbing it on paper you transfer the carbon particles on to the paper.The paper is a insulator.The comibantion of paper and carbon acts as a resistor.You can tryby using a very thin line of pencil on the paper to thick lines on the paper and see the difference in calibrating it and its effect on resistance.You can use it to make a "light dimmer" or controlling volume output in a sound circuit or to control motor speed etc.It can also be used in small circuit or circuits in which it is hard to find the required resistance.

I hope you liked my first instructable.If you have any suggestions or comments or questions you can tell me freely in the comment space or can email me at science4u@gawab.com

Comments

author
DanielK82 made it! (author)2016-04-01

A good fix when you need a 100K resistor but don`t have any. And with a bit of tape it doesn't look too bad :)

IMG_4046.JPG
author
kishcool2005 (author)2007-10-16

It is a good idea buddy...but when days go on ,the resistance value will decrease gradually due to removal of carbon particles from the paper...any how you have given an alternative for resistor...gr8 job..!

author

Simple fix. Put tape over it securely.

author
SinisaJ (author)kishcool20052015-12-11

I think its lapsus lingue, resistance will actually increase as carbon particles are removed from paper... :-)

author
raju1192 (author)2010-01-29

Actually my question is how to connect with Multimeter?
and it will not get heated?
plz answer me.

author
Wobbuffett (author)raju11922015-12-09

You can put the ends on the area covered by graphite (both wires at both ends).

author
Yonatan24 (author)raju11922015-11-04

It won't heat up, the current that is flowing is really low

author
joinaqd (author)2008-12-26

hi i really liked your instructable because its so simple...someone once told me to make resistor out of pencil lead but its hard...your idea is so simple and easy...i hav a question..Can i use this to charge my 6 volt battery using a 12 volt charger if i use the resistor?please answer back.

author
Yonatan24 (author)joinaqd2015-11-04

No, the resistance (ohms) it too big/large/high

author
shaheersa32 (author)2013-06-08

this can also be used to make a lighter, just make a big shape that looks like a upside down V and connect one wire from a motorbike battery or bigger to one side and other to other side here you go instant fire!

author
sonic1234 (author)2008-09-06

what does it do

author
radracer (author)sonic12342013-04-08

Impede the flow of electrons through a conductor.

author
amit13121991 (author)2010-01-17

does anything happen 2 the paper due 2 the heat generated by the resistor.....

author
jrt42 (author)2008-11-14

How about a strip of foil on paper?

author
LkArio (author)jrt422009-11-26

The resistance would be very low, much less than a quarter of an ohm

author
Abizer (author)2007-05-03

very cool.i tried the same project yestrdy . it works

author
a_d777 (author)2007-05-01

very cool thing... i just tried it... i could not find any paper to 'sketch' it on... i took a small calendar and sketched it on that... what wonderful results i got!!! my variable resistor varies from 90k to 1800k... below is a picture of it!

Picture 001.jpg
author
lemonie (author)2007-04-29

What practical range (Ohm) can you get out of this, and how much current will it take?

author
science4u (author)lemonie2007-04-30

I got the resistance range from 10k ohm to 2000k ohm and you can calculate the current from V=IR formula (that is ohms law).If you still have any doubt please do ask.<br/>

author
mje (author)science4u2007-04-30

I think what he's asking is really how much power it can handle. I suspect the answer has to be empirically determined.

author
lemonie (author)mje2007-04-30

Yes, correct on both counts. L

author
Kiteman (author)2007-04-29

You can make a variable resistor directly from the pencil:

Using your Instructables Leatherman (ahem), slit the pencil length-wise. If you're careful, you can split it cleanly along the glue, otherwise you may need to whittle a little wood to expose the "lead" (yes, I know it's graphite) along the full length of the pencil.

Then just clip on wherever you need to.

I like this idea though - I may pinch it to allow my pupils to keep something "real" in their exercise books.

author
Brennn10 (author)2007-04-29

Very cool indeed.

author
Sgt.Waffles (author)2007-04-29

I remember doing this before. Its a pretty cool DIY, and could help to teach youngn's about electronic stuff.

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Bio: I am a student at BITS-Pilani,Goa Campus.
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