Author Topic: Can you tell the value of a resistor from the color bands?  (Read 4824 times)

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Offline SeekonkTopic starter

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Can you tell the value of a resistor from the color bands?
« on: February 22, 2018, 03:52:30 pm »
I can't. No, it is not what you think. I've been in electronics over 50 years. Started by cutting
resistors out of old TV's.  Had a drawer with a couple thousand and I could not only quickly find
the value I wanted at a glance, but one that was pretty close. Now I can't figure them out with a
magnifying glass. I have to use a meter. Brown, red and orange are about the same. Even when next
to each other it is hard to tell the difference. Same with green and black sometimes along with
violet and grey. A variety of background colors doesn't help with minimized ink. I have to get out
a meter to be sure and some times I am pretty shocked at what the value is.  Am I just getting too
old? Basic colors ought to have a standard.
 

Offline Paul Rose

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Re: Can you tell the value of a resistor from the color bands?
« Reply #1 on: February 22, 2018, 03:59:32 pm »
It has gotten harder as my eyes have gotten older ( I'm 47 ).

I've found that a bright light helps quite a bit.  A nice full spectrum incandescent light is best.  I have a lot of trouble distinguishing color bands using an LED flashlight, for example.
 

Online grumpydoc

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Re: Can you tell the value of a resistor from the color bands?
« Reply #2 on: February 22, 2018, 04:37:07 pm »
+1

For some reason it has got much harder.

As you observe all the colours are muddy, indistinguishable and just "meh"; the band spacing is usually totally even as well meaning you can't tell which end to start.

Buff coloured bodies seem easier than blue (which seems to predominate today).
 

Offline rstofer

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Re: Can you tell the value of a resistor from the color bands?
« Reply #3 on: February 22, 2018, 05:08:49 pm »
I have always had defective red-green color vision.  In the '50s, I could read the color bands quite well.  Why?  Well, the Heathkits I was building tended toward 1/2W resistors and larger.  Today, 1/8 watt is more common and they are much smaller.  1W resistors are EASY!

I gave up on color bands for anything other than sorting on the 3rd band many years ago.  I use a meter for every application.
 

Offline ataradov

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Re: Can you tell the value of a resistor from the color bands?
« Reply #4 on: February 22, 2018, 05:53:54 pm »
I grew up with resistors that had their value printed on them. I think this system is way more superior. Color bands may be easier for machines, but as a human, I'd rather rotate the resistor around a bit, and read an actual number.

And I don't  bother learning even basics of color codes. Just store resistors in marked bags, and use multimeter when not sure.
Alex
 
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Offline Muttley Snickers

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Re: Can you tell the value of a resistor from the color bands?
« Reply #5 on: February 22, 2018, 06:35:02 pm »
I did an amateur radio course back when I was 16 and the first thing we learnt was the saying below along with the phonetic alphabet, the teacher added a bit on the end for the tolerances but I could never remember what it was, anyway I never forgot the rest and I'm sure that there would be variations on the theme.

0. Black/ Big
1. Brown/ Boys
2. Red/ Race
3. Orange/ Only
4. Yellow/ Young
5. Green/ Girls
6. Blue/ But
7. Violet/ Violet
8. Grey/ Generally
9. White/ Wins
 

Offline lordvader88

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Re: Can you tell the value of a resistor from the color bands?
« Reply #6 on: February 22, 2018, 06:54:21 pm »
For years I couldn't remember the order, and didn't notice its just the spectrum of colors , starting at contrast black=0 and ending with white=9. So now its easy.

Yeah the 4 band blue resistors are tricky under bad lights. And why not use a pattern or something for the tolerance band.
 

Offline rrinker

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Re: Can you tell the value of a resistor from the color bands?
« Reply #7 on: February 22, 2018, 07:16:22 pm »
 The one I learned it similar to Muttley's but, ahem, not suitable to a family forum.

I have the same problem as the OP. In part I might say it's because I've gotten older and my eyesight has gotten worse - actually only about half there in my right eye. But I do have some old stock resistors from the 80's and I have no problem seeing the color bands on those. The new ones though, especially tighter tolerance ones with 4 bands, it's very difficult. The colors are washed out compared to the fairly distinct colors used years ago. It's to the point where I don;t even bother, I just always have a meter set on ohms and check each one. Size doesn't help, 1/2 and 1/4 watt resistors are huge compared to 1/8.

 

Online grumpydoc

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Re: Can you tell the value of a resistor from the color bands?
« Reply #8 on: February 22, 2018, 07:43:05 pm »
The one I learned it similar to Muttley's but, ahem, not suitable to a family forum.
There was a stink a couple of years ago in the UK when a teacher taught a very non PC mnemonic for the colour code - something about people of race and questionable parentage.

Pretty certain he got sacked for it.

I learnt Black Beetles Running On Your Garden Bring Very Good Weather

Yes, I learnt the other one above as well but it isn't suitable for today's world.
 

Offline IanMacdonald

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Re: Can you tell the value of a resistor from the color bands?
« Reply #9 on: February 22, 2018, 07:51:35 pm »
Colour codes were really useful when they were the standard two digits and multiplier, plus tolerance. Unfortunately, few metal film types adhere to this any more. Thus the first problem you have is the identify the scheme they are using. Then you have to identify which end to read from. This is often impossible due to red or brown being both a tolerance and a value. It's become such a mess that it's easier to whip the meter out.  :-DMM
 

Offline mikeselectricstuff

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Re: Can you tell the value of a resistor from the color bands?
« Reply #10 on: February 22, 2018, 08:00:57 pm »
I wonder if a factor might be poorer CRI (colour rendering index) of LED lighting ?
Not much red, so this may make it harder to distinguish resistor colours
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Offline AndyC_772

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Re: Can you tell the value of a resistor from the color bands?
« Reply #11 on: February 22, 2018, 08:25:25 pm »
I can't possibly post the aide-memoire that I was taught to help remember the colour code sequence.

#1 was 'bastards'.

'Thank' this post if you also grew up before political correctness, and think you may know the same sequence.
 
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Online grumpydoc

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Re: Can you tell the value of a resistor from the color bands?
« Reply #12 on: February 22, 2018, 08:28:19 pm »
I can't possibly post the aide-memoire that I was taught to help remember the colour code sequence.

#1 was 'bastards'.

'Thank' this post if you also grew up before political correctness, and think you may know the same sequence.
That sounds like one I mentioned above.......  >:D

It's the one which goes
0 = ***
1 = bastards
2 = ***
3 = ***
4 = ***
5 = ***
6 = but
7 = ***
8 = ***
9 = without.

I think that's as close as I can get without being banned.
 

Online grumpydoc

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Re: Can you tell the value of a resistor from the color bands?
« Reply #13 on: February 22, 2018, 08:29:48 pm »
I wonder if a factor might be poorer CRI (colour rendering index) of LED lighting ?
Not much red, so this may make it harder to distinguish resistor colours
That thought crossed my mind as well.
 

Offline Dubbie

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Re: Can you tell the value of a resistor from the color bands?
« Reply #14 on: February 22, 2018, 08:55:10 pm »
'Thank' this post if you also grew up before political correctness, and think you may know the same sequence.

I think you meant to say, "Thank this post if you grew up when I and everyone I knew was racist as fuck"
 

Offline hamster_nz

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Re: Can you tell the value of a resistor from the color bands?
« Reply #15 on: February 22, 2018, 10:05:07 pm »
I wonder if a factor might be poorer CRI (colour rendering index) of LED lighting ?
Not much red, so this may make it harder to distinguish resistor colours
That thought crossed my mind as well.

I use a LED desk lamp magnifier lamp and am convinced that it is a size / age of eyes thing. With a little magnification identification is easy. Sorting loose parts into different containers for decades helps heaps.

Anyhow, I only ready need to know black = 0, brown = 1, red = 2, orange = 3. yellow = 4.  That is enough to get pretty much any value I use - eg 330 for LED current limiters, 10k and 100k pullups.

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Offline drussell

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Re: Can you tell the value of a resistor from the color bands?
« Reply #16 on: February 22, 2018, 10:28:15 pm »
I still have no problem with resistors (and I still use mostly incandescent lighting) but yes, I do really notice the lack of spectrum width in anything except bright incandescent or sunlight in today's lighting.  (Not that standard old-school 40-watt florescent are very good either, and that's way older than me... but I've always known about CRI because of them, even way back when I was a kid...  :)

You can see it in many places, you don't need to be looking at a Pantone chart or dfull spectrum, even seemingly simple craft-work threads, yarn, etc.  Just try looking at a DMC thread color chart under most of today's trendy lighting!...  :palm:
 

Offline Wimberleytech

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Re: Can you tell the value of a resistor from the color bands?
« Reply #17 on: February 22, 2018, 10:51:49 pm »
The one I learned it similar to Muttley's but, ahem, not suitable to a family forum.
There was a stink a couple of years ago in the UK when a teacher taught a very non PC mnemonic for the colour code - something about people of race and questionable parentage.

Pretty certain he got sacked for it.

I learnt Black Beetles Running On Your Garden Bring Very Good Weather

Yes, I learnt the other one above as well but it isn't suitable for today's world.

Better Be Right Or Your Great Big Voltage Goes West. 
 

Offline Richard Crowley

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Re: Can you tell the value of a resistor from the color bands?
« Reply #18 on: February 22, 2018, 10:57:19 pm »
I wish I still had some of those resistors from when I was a kid.  Nice brown molded bodies with crisp bright color bands. Easy to read the codes back then.

These days, we have murky or weird body colors on dipped (or conformally coated) "dumbell-shape" bodies.
And horrible band colors that are nearly impossible to read anymore.
I increasingly rely on using my little $10 "Transistor Diode Triode Capacitance LCR Meter" to confirm component values.
 

Offline tautech

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Re: Can you tell the value of a resistor from the color bands?
« Reply #19 on: February 22, 2018, 11:01:33 pm »
I wish I still had some of those resistors from when I was a kid.  Nice brown molded bodies with crisp bright color bands. Easy to read the codes back then.
Yeah, that's what I first learn on too.
Dad's 'little' ones were 1" long and 1/4" dia.  :scared:
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Offline Brumby

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Re: Can you tell the value of a resistor from the color bands?
« Reply #20 on: February 22, 2018, 11:45:25 pm »
I learned the colour codes from a chart on my own - black, brown, rainbow(most of), grey, white - courtesy of my Philips EE20 kit.

After a while, I could 'see' a 47K, quarter watt, 4 band carbon film resistor from its colour codes even if it was far enough away that I had to lean over to reach it.  In fact, everything from 10ohms to 1M in the E12 range didn't require any thought at all.

The eyes aren't quite as acute these days and the range tops out at about 2 ft ... for quarter watt carbon film - BUT the blue bodied metal film are quite something else.  For starters, the darker blue body really kills the contrast which just makes things harder.  Then we have the smaller size of resistor and the bands which, coupled with aging eyesight (though I don't need glasses) makes unassisted viewing more difficult.

I've always had good lighting, so these problems are overcome by using my headband magnifier - but one still remains a challenge: Which direction to read.  With 1% and 2% tolerance bands and values outside E12, I find myself reaching for the meter more often these days.  With some of the stock I have, the tolerance band is spaced out a bit more - but it's just not consistent and/or obvious.

I used to be able to pick out a value from a fistful of resistors dumped on the bench - but with the smaller blue bodied beasts, those days are gone.
« Last Edit: February 22, 2018, 11:47:04 pm by Brumby »
 

Offline Dubbie

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Re: Can you tell the value of a resistor from the color bands?
« Reply #21 on: February 22, 2018, 11:58:37 pm »
I find I just keep my LCR meter next to me and jam them in to quickly tell me the value, even if I bother to try and read the value, I never quite trust myself and end up measuring anyway.
 

Offline sibeen

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Re: Can you tell the value of a resistor from the color bands?
« Reply #22 on: February 23, 2018, 12:01:42 am »
rushes in

I hope I'm not late to this meeting of the grumpy old bastards club :)

I actually had to look at a colour code just a few days ago. Looked at it under a light, then got out the newer glasses with higher magnification, then put it under a magnifying glass and then got out the multimeter.

Mine started "Bad boys..."
 

Offline ArdWar

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Re: Can you tell the value of a resistor from the color bands?
« Reply #23 on: February 23, 2018, 12:42:41 am »
It's always brown-red or red-orange that gives me the most problem, much more if it's old fading part. Some use better, easily discernible paint than others. Some use certain shade of base paint that exacerbate things.

My other problem is with 1% resistors. I always not sure if it's read one way or the other way around. ;D
 

Offline ikrase

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Re: Can you tell the value of a resistor from the color bands?
« Reply #24 on: February 23, 2018, 02:04:49 am »
I find it remarkably difficult to tell which end of a resistor is the most significant digit and I'm pretty young.
 
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