about resistors

[goblin_techies]

why do resistors use color codes for determining their value???......

why not just print the resistance value??

 

[maor]

resistors have a round shape not square printing values will look wierd.
also what about big numbers?
i mean comeon its just two numbers and some zeros is it that hard?
edit:
if your'e having trouble about memorising the color codes go here:
**broken link removed**

 

[goblin_techies]

i cant accept that....
how about capacitors?? they have a round shape too

 

[maor]

...
dude caps are bigger and have more room to write on unlike resistors they are small in leanth and width so its practacly impossible and if your'e talking about non electrolitic caps they have the numbers written first two digits are numbers and the third digit is the amount of zeros and its starts from pf's

 

[Styx]

how about... thats how it is and thats how its gonna be for a long time

 

[stevez]

I'm guessing that "why" color codes were done in the first place has to do with the complexity and capability of equipment years ago - and less to do with what can be done today.

 

[audioguru]

I have some very old Japanese radios and the numbers on the resistors and ceramic capacitors are written by hand!

 

[Souper man]

The axial ceramic caps on old TVs and stuff...

O GOD! TOO MANY COLORZ
(some had like 6 bands on a tiny little casing)

 

[bananasiong]

why do resistors use color codes for determining their value???......

why not just print the resistance value??

The value of diode is printed on it, sometimes it is difficult to identify what's its parts number on the PCB. But I can identify the color codes for resistors easily, this is the advantage.

 

[Souper man]

It makes it easy to see a certain pattern, and automatically know it starts with 10 for example, then just look at the last band, and multiply it. Makes it quicker if you know your color values.

 

[maor]

The axial ceramic caps on old TVs and stuff...

O GOD! TOO MANY COLORZ
(some had like 6 bands on a tiny little casing)

you know all six bands have a reason
1st band:first digit
2nd band:second digit
3rd band:amount of zeros
4th band:tollerance
5th band: is for 1% metal film resistors
6th band: the temputare it can suffer

 

[Souper man]

Of course!

 

[Speakerguy]

One more reason to use SMT parts. 103 = 10k resistor

 

[justDIY]

i cant accept that....
how about capacitors?? they have a round shape too

that's a subject that irks me.

I can buy 0402 resistor (tiny as heck) and they have their value printed on them (small yes, but it's still there).

however, even a mighty huge 1210 ceramic cap will have no value printed on it, despite having a 'football field' sized area to do so.

 

[Styx]

thats cause the value isn't the ONLY signficant thing w.r.t. caps
Sure resistors have value (printed on them), wattage (get use to the size), voltage (50V is pretty standard)
But caps... you got a hell of alot of different voltage rating (some only a volt different), di-electric, ripple-current, temp capability and that is even before you get to the actual capacitance, to which you have a wider range of values, all the way from pF upto F...

There just isn't enough room. Even CaseA Tants have tried to squeeze on the main ones (voltage & capacitance), but have to neglect the others

 

[justDIY]

your explanation makes sense, but it'd still be nice to have something to go on, instead of nothing at all. I've got three strips of cut-tape ceramics that got mixed together, before I could write the value on the tape... so now I've got 0603 sized .33 uf , .22 uf and 2200 pf in a jumble. I could get a capacitance meter and measure 'em, but eh, its only a few dollars worth of parts.... just a loss I guess, be more careful next time

 

[Baske7Cas3]

Ok, well I have a a beginner question about the resistor color codes... How do you know which way to start reading the bands? For example, all the examples I see has all the bands are near one side, but when I look at a circuit all the bands are placed evenly across the resistor so I don't know which way to read it... Also, this one is for goblin_techies.... Do you play Dota?

 

[Nigel Goodwin]

You start at the opposite end to the tolerance band, which was easy with 5% and 10% resistors, but not so easy with 1% and 2% ones - in which case just read it both ways, one will make sense, the other generally won't!.

 

[Baske7Cas3]

That doesn't sound like a very stable reading system lol.

 

[RODALCO]

The other advantage of coloured rings it that the R value can be determined from any angle while still soldered in the circuitboard.

Have you tried to read the value of a Zener, or 1N4XXX in circuit when the installer soldered it in with the numbers facing the board ?

After you work enough with the colour coding you get used to the E12 or E 24 patterns.

It is good practise to check with an Ohmmeter the values, especially when the red and orange look almost the same in colour and if you are in doubt about the Res. value.