Sorting resistors

color band, or do you get down finer than that?

At my school, they are "sorted" by value (3 bands). The problem is that students don't always know the bands, or they don't look carefully, so you'll find resistors off my a magnitude or more.

It depends on how you use resistors. If you find more often that you need one of a specific magnitude, rather than a specific value, sorting by the third band makes sense. I don't yet have enough that I need to worry about sorting, but if I did, I think I'd sort by the first two bands, if not all 3.

It also depends on how many "buckets" you have to sort into. If you have only 5 buckets and don't have anything higher than 9.9M?, then that's your answer ;-)

I should mention to take my advice with a grain of salt. I'm only just starting on this adventure myself ;-)

third color band, or do you get down finer than that?

We buy 1% TH metal films for something less than $0.02 each. I calcualted what my time is worth, (salary+benefits+overhead+profit) And how long it takes me to identify a resistor and put it away in the right bin..(say one or two seconds with a DMM) I save the $0.50 caps, and sweep the R's into the trash. I always feel a bit guilty, they're fricking 1% resistors! I could save them all in a bag and mail 'em to you at the end of a year.

George H.

color band, or do you get down finer than that?

Six little plastic drawers across in the "organizing thing with lots of little drawers" (proper name is ?). The ordinary 5% through-holes are sorted by third band, with the last drawer being "1 meg and up" (not many in that one). Specials -- precision, DIP arrays, big-ass power resistors, etc. -- get a drawer for each type. Surface mount assortments are in little plastic strips in a couple of small boxes.

How finely you do it sort of depends on how many you have, how many drawers or boxes or bags you are allotting, and how much time you want to spend looking for one when you need it, and how obvious you'd like to to be that you don't have some values.

Right now, I have a mess. I hope to dig out of it, but I haven't wanted to invest too much in storage hardware, so I have a mess.

At a job where it was more a part of the job, they were sorted into 24 drawers by the 5% first two bands, and then dividers in the drawer sorted the third band (possibly only completely separate for common values, with others lumped & sorted out by third band as needed - it's been a couple decades.) I wanted to have stock of every value on hand for that job, and that arrangement made it easy to tell if I needed to order any. 1%, power etc were special cases beyond this system.

so:

10 11 12 13 15 16 18 20 22 24 27 30 33 36 39 43 47 51 56 62 68 75 82 91

I color-coded the drawers for good measure, as I recall.

I've thought about using large test tubes or culture tubes as a cheaper method to rack and organize than the plastic organizer drawer things.

Better yet, I should cook something up in the woodshop - it will be more satisfying, if I can find the time.

--
Cats, coffee, chocolate...vices to live by 
Please don't feed the trolls. Killfile and ignore them so they will go away.

There is a good thought there.

Find a school that has a hands on electronics program that can use your resistors then save them up and give them to the school. The students time for sorting is not expensive - and you get to do something good!

third color band, or do you get down finer than that?

20% were common, and some 50% resistors were in equipment I repaired. I bought a dozen metal frame, 50 drawer parts cabinets in 1970 and sorted out everything. Over the years, I've more than doubled the cabinets but I rarely have to sort anything now. I cut index cards nd folded them into dividers so I could put two 5% values ber drawer and ignored the wattage. Small capacitors, connectors, transistors and some hardware fill the rest of the cabinets. It doesn't take long to sort SMD resistors or capacitors with tweezer probes. Sometimes they get mixed up on the bench, and you are almost out of a value. That makes it worth sorting. Somewhere I have a box of about 10 pounds of SMD resistors, caps & other parts that were pulled at rework. A lot of them were mis-stuffed by an outside contractor, or boards were reworked from one rev to another and they didn't reuse the parts.

You may have some undiagnosed color blindness at work, too. The most common color blindness is a complete or partial inability to distinguish green and red (the red cones are actually missing, or are sparse, or the pigment is too close to the yellow cones' pigment, I'm not sure which).

When that happens violet and blue look the same, as do green and gray, and red and orange (or orange and yellow, or red and brown). Basically the blues and yellows work just fine, but blue + (red or green), yellow + (red or green), and gray + (red or green) don't.

I have this condition in the partial form. For the E96 series I can usually get the first two digits because not all of the bands are used, but I need to use a meter for the multiplier band (and 220 looks like

330, and 120, etc.)

I have enough bins to cover 47 to 470k in the 20% value range. Within that I just look at the bands.

Besides, these days resistors don't have color bands -- if you're lucky they have numbers, and if you're not they're just little black rectangles with silver ends.

--
My liberal friends think I'm a conservative kook. 
My conservative friends think I'm a liberal kook. 
Why am I not happy that they have found common ground? 

Tim Wescott, Communications, Control, Circuits & Software 
http://www.wescottdesign.com

To be fair, in the old days when the resistors all came from Big Name companies, the resistors were all brown, and the color coding on top of that, it was pretty easy to read the color code.

Then the imported resistors, more like a sealed package, the color was no longer consistent. It was obvious if you had the close together colors together, but by itself it became harder to tell.

The big mistake beginners make is to try for some scheme. All those mneominics and color wheels and such, when they should just be learning the color code. It's not unlike learning morse code, if you look up on a chart rather than hearing the sound of the character, you waste time and can't catch up. If you don't do a direct translation, "there's red, that's two" not even thinking that much, then sorting will be a tedious process. A look up table, such as a mnemonic, just has the sorter spending time remembering the mnemonic.

That said, if the color isn't clear, I'll just pull out the DMM. I often tend to do that anyway, worried that the cheap resistors have been coded wrong, or changed value.

It's easier to check parts as you solder them in than try to figure out why something isn't working.

Michael

Hi Tim,

Tim Wescott Inscribed thus:

Since you mention it, how do you decode the value for the ones that have four numbers ?

--
Best Regards: 
                        Baron.

It's the same algorithm, just an extra sig fig.

There's a handy free tool at that also includes a decoder for SMT resistor codes like "A22".

the third color band, or do you get down finer than that?

e h

I put the common values, 100, 1K, 10K, 100K, 1M in their own drawers. The rest are sorted in ranges, so most all 1/4 watt values are in 20 drawers. I stumbled on some 8 pin SMT resistor packs with four 10K resistors each. Each one of those can be arranged as a single 10K,

15K, 20K, 30K, 40K, 5K, 2.5K, and a few others. I haven't worked out all the possibilities.

-Bill

color band, or do you get down finer than that?

I go finer, I sort to E6

--
?? 100% natural

I have reels of resistor networks. They, and the other reels of resistors are sorted by resistance, tolerance, then size.

I was starting a business when I set up my inventory and decided that I couldn't waste the time looking for parts if I wanted to make money.

Four numbers means it's a 1% or better, and you decode it like the 1% resistor color code (XXX * 10^Y). The hardest part for me is remembering that I can't just "bin at a glance" by looking at the multiplier band -- i.e., yellow does _not_ mean 100k-ohm range, it means 1M-ohm range!!

--
My liberal friends think I'm a conservative kook. 
My conservative friends think I'm a liberal kook. 
Why am I not happy that they have found common ground? 

Tim Wescott, Communications, Control, Circuits & Software 
http://www.wescottdesign.com

I sort by the first 2 bands - E24 series only needs 24 component drawers.

color band, or do you get down finer than that?

--
I sort E24 from 1 ohm to 10 megohms by the first three color bands, 
for a total of 169 drawers.

Another factor is the lighting in your shop. When the lab where I used to work started stocking a lot of 1% values (which had a light blue body) everyone noticed that it was hard to tell brown from red. One guy (avid photographer) started looking into lighting, and replaced some of the overhead fluorescent tubes with a special daylight-balanced type. Presto! Suddenly the reds jumped out and looked nothing like the browns.

However, the room as like "perpetual sunrise". Sounds good, but after a while it got to be "too much of a good thing". We ended up with the special tubes just over the resistor cabinets.

Best regards,

Bob Masta DAQARTA v7.21 Data AcQuisition And Real-Time Analysis

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third color band, or do you get down finer than that?

haha, 50% resistors. never heard of that one. Russian equipment?