How to read resistor and capacitor values.

[DrNomis_44]

Hi everyone, seeing as there was quite a bit of interest in the last two tutorials i started, I thought that I would do another one, so, here's a mini-tutorial on how to read resistor and capacitor values.



Here is a pic of a resistor to show you what they look like:





And here is a pic of a capacitor:







The resistor is marked with four coloured bands, the first three coloured bands indicate the value of the resistor and the forth band indicates what's called the tolerance, or how much + or - of the marked value the resistor can actually measure.


Now, each of the first three coloured bands marked on the resistor can be any one of the following colours which represent the following values:


Black 0

Brown 1

Red 2

Orange 3

Yellow 4

Green 5

Blue 6

Violet 7

Grey 8

White 9

Gold .1

Silver .01


The fourth coloured band can be any one of these colours which represent the following tolerance values:


Brown 1%

Red 2%

Gold 5%

Silver 10%


Here's how the resistor colour-coding works


First colour band = First significant number.

Second colour band= Second significant number.

Third colour band= Number of added Zeros.

Fourth colour band=Tolerance +/- the marked value.



Using the resistor in the pic as an example, it is marked with the following colour bands:


Yellow, Violet, Orange, and Gold.


Which indicates the following value:


4, 7, 000, and 5%


This decodes as a 47,000 Ohm resistor with a 5% tolerance, or 47k / 5%.



The value marking on a capacitor is marked similar to a resistor except that it is usually marked as a 3-digit number followed by a capital letter, but it is read in the same way as a resistor, the first two digit from the left indicate the two significant numbers, the third digit indicates how many Zeros to add, and the capital letter indicates tolerance.


Using the cap in the pic as an example, it is marked 684, which reads as follows:


6, 8, and 0000, or 680,000, or 680nF.

[Muzza]

Doc, you put too many zeros in your example.

[DrNomis_44]

Doc, you put too many zeros in your example.

Oops, so I have, I'll go and sort that out, cheers for letting me know about that Muzza.


Update:


All sorted now, it should look correct.