March 3, 2013

(Mostly) Organized Resistors in 20ish Drawers

Organizing electronic components is important if you want to spend more time building prototypes than looking for the right resistor. The problem is, there's just way too many to organize without spending a ridiculous amount of money and space on a billion little drawers....

Resistor color codes are really quite easy. Each color represents a different number, with 10 total colors (0-9). On the 4 band version (by far the most common), the first two bands make up the base value, the third band is a 10^n multiplier, and the last band is the tolerance. For example, a 4.7 kilo ohm (4,700 ohm) +/- 5% resistor will have the color bands:

$$yellow - violet - red - gold$$
The yellow and violet are 47, and the red is a 10^2 multiplier.

$$47 \times 10^2 = 47 \times 100 = 4,700$$
Easy, right? The tedious part is remembering which color goes with which number, but google has no short supply of images to help you out there.

Rather than offering any resistor value you can imagine, manufacturers (and whoever else decides this stuff) offer common resistor values. The idea is that you can make up any value you need with a combination of these values. Notice how the same base number is used in each row (columns differ only by the position of the decimal point).

As I've tried to grow accustomed to resistor color coding, I have found that if I try to read all the colors at once my mind gets rather bogged down trying to remember the colors and do the math. But if I look for a single color in the same position every time, I can do it quite easily. With this in mind, and in an effort to reduce the number of drawers needed to sort my resistors, I decided to lump resistors together in a single drawer by base value and manually sort by order of magnitude.

So I made up some drawer labels and so far so good on the organization. If I need a 1.5k resistor, I just open up the "15_" drawer and look for a red multiplier band. 20k? Open the "20_" drawer and look for orange. 68 ohm? "68_" drawer and look for black. Easy.

Here's the Illustrator file (and .pdf) I made for my labels. It's made to be printed on Avery File Folder Labels (template 5202), and each Avery label fits three drawer labels. I trimmed the common resistor values list down a few so I could fit them all on one sheet.


  1. Great system. This will save me time on each project.
    Many Thanks

    BTW: The code for 75_ seems wrong. Should it be purple, green,_ ?
    Currently, I see 56_ with the same code as 75_.

    1. Thanks for catching the 75_ error. I'll update it shortly.

  2. Hi Nich, thanks for publishing this in Illustrator format, I was able to import it in to Inkscape and use it no problem. I've corrected the error and organized the glyphs to print nicely on Avery 5160 labels, I published the new document here and link back to your page a couple of times. Let me know if you are not okay with this.