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Possible Duplicate:
Resistor suggestions for colorblind person

My color deficiency is bad enough that a year of fiddling with resistors in high school was enough to frustrate me right out of considering EE as a career. I'm spending a fair chunk of time on the arduino now, but it is still a frustration: identifying resistors.

Most of the seasoned EEs I know could scan through a pile of resistors and spot the one that they're after, looking for the pattern of colors that they knew would be on the parts. For me, this is quite simply impossible. If you think it's no big deal, try finding your resistors in a pile with only the light of a deep blue LED to work from.

So, before I go out and buy 500 of every resistor and just dispose of them every time I pull them off a breadboard, does anyone have any suggestions? I'd love to find a supplier of axial resistors who actually prints resistance values instead of color bands. Failing in that, I'd even resort to stickers. I'm not about to pull out my phone to try to ID resistors. That would take more time than futzing with the multimeter, and I want a better solution than that.

Thanks.

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marked as duplicate by Brian Carlton, stevenvh, AndrejaKo, W5VO Aug 16 '12 at 11:20

This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.

  • \$\begingroup\$ I had this problem as well when working at a physics research lab in college. Nothing is quite so frustrating as the various shades of green, red and blue used by different manufacturers. If only they each used the same color palette, it would have been theoretically possible. \$\endgroup\$ – David Navarre Aug 15 '12 at 21:39
  • \$\begingroup\$ I use the most amazing LED worklight that has several modes. It is made for painters but sure helps me on the workbench. Here it is: amazon.com/… -- The best mode brings the colors out extremely well - for me it is a must-have as the Mark 1 eyeballs age. For general information on how this all works, check out the video at the end of this for an explanation of the Color Rendering Index: blog.1000bulbs.com/home/how-to-choose-lighting-for-paint-colors \$\endgroup\$ – SDsolar Aug 5 '17 at 4:19
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Get a cheap DMM, and a small breadboard. Wire the DMM between a couple columns, even parallel a few adjacent columns together so you don't have to be accurate when placing it. Then, when in doubt, just stick the resistor in your breadboard. You should really measure every resistor you use anyway. Mislabeling and defective parts do happen in large batches.

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    \$\begingroup\$ Get a nice DMM instead. The auto-ranging for the ohmmeter on a Fluke is so much nicer than an Extech. If I had to ohm out resistors all day I'd definitely choose a Fluke, even if it's a low end one. \$\endgroup\$ – Ben Jackson Aug 15 '12 at 23:22
  • \$\begingroup\$ @Ben - Fluke has great DMMs, but isn't cheap and seems overkill if you just want a resistor measuring device. But you'll indeed want auto-ranging. \$\endgroup\$ – stevenvh Aug 16 '12 at 7:31
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    \$\begingroup\$ @Matt - Why the breadboard? Can't he just fix the probes 3 cm apart, and push the resistor against them? \$\endgroup\$ – stevenvh Aug 16 '12 at 7:32
  • \$\begingroup\$ I've seen probe tips which have a sort of plastic cover on them so that only the sharp point of the tip is exposed. These are great for resistor testing since they allow good contact with the resistor while it's on the paper line. This way, there's no need to actually remove resistors for testing. Also half of 10k resistors I have have 1k markings and half of 1k resistors have 10k markings. \$\endgroup\$ – AndrejaKo Aug 16 '12 at 8:11
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axial leade resistors with printed values

There are axial leaded resistors with the values printed on them. Until surfacemount parts became standard, we used these exclusively in mil-spec electronics.

One manufacturer is Vishay/Dale.

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Good news! Color-coded resistors are obsolete. All my recent designs have used 0402 SMT resistors that are completely unmarked and anonymous. So don't fear becoming an EE: you are on a level playing field with everyone else.

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    \$\begingroup\$ MLCC capacitors have never been marked, even if they're large enough to print a complete encyclopedia on them. :-( \$\endgroup\$ – stevenvh Aug 15 '12 at 17:41
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    \$\begingroup\$ And when they fall down they might as well be grains of sand. \$\endgroup\$ – starblue Aug 15 '12 at 18:31
  • \$\begingroup\$ But they don't cost that much more than one. \$\endgroup\$ – joeforker Aug 15 '12 at 20:34
  • \$\begingroup\$ While color codes may be less important for resistors and other parts, wires are still color coded as much as ever. Gnd, power, signals... \$\endgroup\$ – DarenW Aug 16 '12 at 7:33
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You could switch to SMT. SMT resistors have their resistance printed in digits on them, like "473" being 47 kΩ.

enter image description here

As markrages points out the smaller ones, 0402 and smaller, downto 01005, don't have any marking, but since you're currently using PTH the size of an 0603 or 0805 probably won't be a problem.

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  • \$\begingroup\$ Not a great idea for working with breadboards. \$\endgroup\$ – m.Alin Aug 15 '12 at 18:45
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    \$\begingroup\$ @m.Alin - not for solderless, no, but they work without problems on veroboard. \$\endgroup\$ – stevenvh Aug 15 '12 at 18:58
  • \$\begingroup\$ I might have to pick up a bunch of them and solder legs on them. Probably won't be very sturdy, though. I guess I could cut up protoboard and solder the resistors and legs to the holes in the protoboard. Thoughts? \$\endgroup\$ – user30997 Aug 16 '12 at 16:55
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Tinted contact lenses. Differently colored lenses for each eye, or a colored lens in just one eye. Tinted regular reading glasses ought to work too, I suppose.

Idea no has tried yet, AFIK: wear polarizer glasses, such as for watching a 3D movie, and colored lamps with polarizers illuminating the work area and parts containers. Not sure which colors would work best, so long as your two (or more?) eyes receive different impressions of the scene where there are colors.

BTW, my paternal grandfather was color blind, and was an artist who painted pictures of big ships in the great lakes. He had to get correct colors on flags, logos on the ships, etc. Grandma may have helped review the finished works, but mostly he relied on clearly labeled tubes of paint and written sources describing the flags, etc.

Online info, from quick superficial search (quality not guaranteed):

http://www.colblindor.com/2008/03/29/improving-color-vision-with-lenses-for-the-colorblind/

http://www.scripps.org/news_items/4271-many-shades-of-color-blindness

http://www.colour-blindness.com/solutions/cure/

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  • \$\begingroup\$ I'm quite familiar with the tinted lenses trick. They are designed to help you distinguish colors, but no solution can get a color deficient viewer any closer to identifying colors. I've tried about a dozen different shades for my work in the games industry and they're worse than useless. There are people who are very functional color deficients. The level of my deuteranomoly is so deep that I am nearly dichromatic. =[ \$\endgroup\$ – user30997 Apr 23 '13 at 23:36

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