Instructables

HOW TO CALCULATE RESISTOR & CERAMIC CAPACITOR VALUE.

Picture of HOW TO CALCULATE RESISTOR & CERAMIC CAPACITOR VALUE.
You all must have had a problem while make your projects and searching old pieces of circuits for a particular resistor or a capacitor.

Well , using a multimeter is a good option but  it may not be available to most of us, and using it is a bit complicated and I will be posting it in  my next instructable on it.

Presently, I will tell you the criterion for calculating the resistance and capacitance.(Only in ceramic capacitors as it is mentioned on electrolytic capacitors)
 
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Step 1: MOTIVATION

I was making a school project and I needed some resistors and capacitors, as the local electronics shop is about 20km from my house saw I started to look in the old circuit boards I have.

As I didn't have a multimeter so I tried to understand the logic behind the codes.

Which I will be telling you.


Step 2: THE RESISTOR

Picture of THE RESISTOR
First, of all I would Like to start off with a few basics.
For those of you who don't know what is a resistor, it is device that resists the flow of current.

The colour code is just, the resistance in the forms of  coloured strips.
The colours include-
 
1. BLACK
2. BROWN
3. RED
4. ORANGE
5. YELLOW
6  GREEN
7 .BLUE 
8. VIOLET
9. GREY
10.WHITE

Now, the first two strips of the resistor represent the digit and the third is the multipier band .
And the fourth band gives the tolerance.

The image is from  --http://www.doctronics.co.uk/resistor.htm


Lorddrake1 year ago
just trying to understand ... I think there are a few discrepancies

under calculating resistance .. is the first band color supposed to be green instead of yellow?

is it a supposed to be red band to get 5700 or an orange band to get 57000?
waldosan1 year ago
funny story: i once spent an entire night looking through my resisters to find a few 10k ohm resistors, I started at 9 pm and it wasn't until 2 that i realized i was reading the code backwards!
Aha!Thats why I use my multimeter instead of decoding.
raikut1 year ago
Well the picture that you have given in Step one. Is that a circuit board that you have made. If yes i would like to see its schematics.
pranjal12 (author)  raikut1 year ago
Well I took it from google just to explain you.
You can find it on google images.
Zakery1 year ago
Thanks a ton, This will come in handy for me.
samaddon1 year ago
i got 1 question to ask can you please tell me what this ceramic capacitor does?
i've got a ceramic capacitor it's blue in color in front 471 and 2KV is written what is the meaning of 2KV??
pranjal12 (author)  samaddon1 year ago
Well ceramic capacitors like other capacitors store energy.. The only difference is that it uses ceramic material as a dielectric.
The 2KV is the voltage rating it means 2000 Volts.
For information refer to http://en.wikipedia.org/wiki/Ceramic_capacitor
samaddon1 year ago
Very good i also have some problem calculating the capacitance of a ceramic capacitor but it really solves my problem i am not well known to electronics cause i am only 15 yrs old! Sooraj Bhaiya!