Instructables

Make a Resistor Reference Card

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Way back when I very first started getting interested in electronics, and radio shack was more than a mini best buy, I picked up an invaluable learning aid / tool.

It was a simple piece of cardboard with 3 wheels inside of it, dial in the colors and it told you the values of resistors, capacitors, and on the backside 2 scales of inductors! (catalog number 271-1210)

While no replacement for proper education on the subject, it proved itself more than useful, so useful I still own the darn thing to this day 20 + years later, and even mention it in one of my Instructables as "the best darn piece of cardboard they don't make anymore".

The problem with it is, when radio shack changed from Archer brand stuff in brown packages to R (circle) stuff in blue and white packages, and eventually dwindled their electronic supply down to a couple of cabinets from 3 walls of the stuff, this handy device disappeared.

Without getting into too much RS / Tandy / Archer history, I would guess it had not been produced since the mid 1990's ... and thats a shame.

I have been meaning to make my own similar version of the card ever since I started Instructables, but ironically, I was going nuts trying to figure out a cardboard project for the "Gorilla Glue Cardboard Contest"...

Then one night, planning out how to shove a Cmoy amp into a 9volt battery, I was using this thing and all of a sudden all the DUH's came into place!

Welcome to my 6th Instructable.
 
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nerd74739 months ago
does RadioShack still sell the cards?
osgeld (author)  nerd74739 months ago
nope
J-Five2 years ago
On a Commodore 64 simulator I made a program that asks if it's a 4 or 5 band resistor. You type in the color, then it matches it witch the right color (i.e. green then value would be 5) for the rest of the significant bands. Then it does the same thing for the multiplier band. (I.e. blue would be 10^6). And finally it asks for the tolerance value, and calculates the lowest to highest possible value.
BTW Its a split pin. LOL
MacabreRob3 years ago
Very nice. Very handy. Just printed it out at work (they have the color printer) and going to assemble it tonight. I was teaching my son some basic electronics a couple weeks ago for a Boy Scout merit badge and had him looking up the color values from an index card taped up on the back of my electronics kit box. This will make it easier.

I just hope I don't lose it... :-)
mab00853 years ago
good one
wout smeets3 years ago
it works graet

thanks bro
osgeld (author)  wout smeets3 years ago
Your welcome!
zack2473 years ago
THANK YOU! i have been killing myself having to figure out resistors! now thanks to this i can easily figure it out without having to search up a resistor color code chart on the internet.
osgeld (author)  zack2473 years ago
your welcome, and the more you use one of these the less you need to
zack247 osgeld3 years ago
yes, especially when im away from the internet! 5*s
DocAmpuT3 years ago
I was in dire need of using the like resistor calculator after our 9th grade teacher showed us those things a couple of years after teaching the politically incorrect version of the color bands memory aid that my father had used also.

The prime reason I did use the calc thing from Radio Shack was because I was lazy and it was a bit quicker than figuring values in my head. ** grin **

Oddly enough, I still have that thing in workable shape sitting in my office. Probably because it got a break after one of the first programs I ever wrote for any home computer served the same purpose in letting me put the bands in and having it quote a calculated resistance for me on an old Commodore Vic-20.

Did you resistance calculator look like the one in this uploaded image I'm including?
Image1.jpg
osgeld (author)  DocAmpuT3 years ago
Yes thats it!

you can see mine in a picture on step two, and I still have mine today also
fundash3 years ago
I must make this!
I realize no one has posted here in almost a year, but since I just now came across this, and have been tearing my hair out over resistors for ages, I figured I'd say thank you:). Just now finished mine, I used photo-paper instead of cardboard, so it's probably slightly less sturdy, and used rivets to fasten it. Now I'm off to make a second one, since the first was more of a hasty prototype, as I was unsure if the wheels would still move after being riveted (They do). Thanks again!
kroq-gar784 years ago
relatively simple project. going to make one as soon as possible!
awesome idea!!
i just finished mine now, it oozes amazingness, lol
J-Five4 years ago
I am impressed!!!!

Osgeld you are a genius!!!

Very clever
mischka4 years ago
this is very useful, thanks a lot
osgeld (author)  mischka4 years ago
Thanks, and your welcome
jgscott9874 years ago
I have many fond memories of the cardboard resistor wheels. I've found that a simple table is a lot easier and more straightforward however. I keep this chart above my bench and I can refer to it without even taking my hands off what I'm doing.
That is great, thanks. I have troubles with oranges and reds, and although they are clear on the chart, on a resister they sometimes are much less so.
 
osgeld (author)  Goodhart4 years ago
agreed
Goodhart4 years ago
Very nice.   At my workbench, I use a chart (as someone else mentioned) but when away from my bench, this would be a VERY valuable tool.
 
5tgb6yhn4 years ago
I used 1/4" brass grommets instead of brads for a cleaner look.  A lot stronger too.  Grommet kits, made by either Stanley or General, are readily available at most hardware stores.
I have a friend who is colorblind, and now I kind of want to make him a little scanner device that can read the colors off a resistor and tell him what the resistance is... Hmm... *pondering*
ohm meter?
nawh, that would be too simple...
Exactly!
Why would you bother making something to read the colors off a resistor only for it to change it back to its resistance, or build something to read the colors and then tell him the colors so he can re-decode them? And that would require a lot more electrical work and be less accurate than a ohm meter. Also, what if he is working with a SMD resistor, then the color reader thing woulding work... (well, neither would the card here, but the ohm meter would read both through hole parts and SMD parts, resistance wise atleast) Or better yet, get a a MULTI-meter
hey so am i instructables is red to me
Great little helper - exactly what I was looking for :)
Dipankar4 years ago
Sharing this with us is really great. It comes in very handy. Thanks.
osgeld (author)  Dipankar4 years ago
Thank you everybody for your kind comments!
ausome nice idea but what did you use to make the card
osgeld (author)  knexsuperbuilderfreak4 years ago
The card itself is made out of thin non corrugated cardboard, the graphics were done on Inkscape + The Gimp
static4 years ago
Far out man, slick work. I can see some one making a super sized version for wall art in the shop. 5 stars.
sharlston4 years ago
theres some free software that has a resistor thing for coputers :)
tundrawolf4 years ago
That's pretty slick! good idea, thanks! I'll give you $5 to print out another piece of cardboard and send it to me. Just kidding! :)
3vilnat34 years ago
This sounded like a good idea for college, so i made one in my college colors. i think it turned out really well. great idea!
scan0005.jpgscan0006.jpg
osgeld (author)  3vilnat34 years ago
looks good! (I was wondering when I would see others artwork on this)
NEIN4 years ago
How awesome would this be as a BUSINESS CARD!!
conrad24684 years ago
great instructable, but i prefer the ipod app just cause its an ipod app.....worth 5 stars though!!
simplebeep4 years ago
I love this. I can never remember what those darn transistor colors mean; and even if I could, I would be constantly second-guessing myself.
It's so simple, yet such a great idea!
pravardhan4 years ago
My 1st PUC (Class - 11) teacher taught it as:
"B.B.Roy Of Great Britain had a Very Good Wife"

Very Good Idea, But where to find a Colour Printer. I have two B/W Laser Printers!!!!!

5 Stars from me. -
crazzzy14 years ago
lol 660 so close
foo its been on the web for like 5 days and its featured already thats smart
D.L.H.4 years ago
The idea is very cool and helps in the long run.Glad that someone made this.
mdog934 years ago
Could i scale it down to fit between two credit cards (old gift cards or something similar)? mdog
osgeld (author)  mdog934 years ago
yes you could, just make sure to scale everything down at once (or it might become a nightmare)
mdog93 osgeld4 years ago
yeah i didn't do that it took ages and because the scale factor of the width of the card isn't the same as the scale factor of the height of the card etc. I couldn't do it all in one go. Also the wheels are very small now, so small that the gap between the ring of numbers and the edge of the circle isn't enough that it can stick out far enough ( of the top of the card) to turn it without seeing the numbers poking out. but you could manage with it, but it's a bit dissapointing saying that i spent a couple of hours resizing it. nvm mdog
itsachen4 years ago
haha very cool! I just remember BBROYGBVGW with a handy but politically incorrect mnemonic my teacher taught me. This would have come in handy though!
Was it "bad boys rape our young girls but violet gives willingly"? My 10th grade physics teacher taught us that back in the day (almost 30 years ago).
YES.
Except my teacher changed bad to black...>>
That's so funny that it goes back so far
Bad Beer Rots Our Young Guts But Vodka Goes Well. Get Some Now. Black Brown Red Orange Yellow Green Blue Violet Grey White. Gold Silver None 1,2,3,4,5,6,7,8,9,0, 5%, 10%, 20%
Very awesome, thanks for that tip!
No problem.
szechuan534 years ago
printers... printers never change. :D
FALLOUT!!! YOU BETHESDA-SOFT LOVER!!!! Lol, jk. Great reference. -PKT
Patented4 years ago
Wow! What a nice and easy to do tool! thx a lot im making one right now Well done! 5*
i can't open the .svg file!
osgeld (author)  mashedpotato134 years ago
what program are you using?
Chad-Nadir4 years ago
they're called split-pins
they are also called Brads, not to be confused with Chads...
I never knew dat...,
omnibot4 years ago
Excellent! I'll run down to the shop to have it printed today!
geeklord4 years ago
Yea, i was able to memorize the colors in ~2 days, but for people who can't do that, this is great!
ikestarm174 years ago
That's really cool (even though I just use a multimeter usually!)
oh now i get the usage hehe thats sad but now i get it SWEET
J-Five4 years ago
It makes reading resistors a lot easier.
wow 2o years ago man nice instuctable
Sandisk1duo4 years ago
thanks for making this!
bulsatar4 years ago
might be able to use 3 small rivets instead so that you can use the back of the wheels and the back of the card for a second reference for whatever.....?
osgeld (author)  bulsatar4 years ago
yes, the radio shack one actually uses 3 rivets, but I dont so I used those paper things
starwing1234 years ago
This is a great idea, for when you don't want to risk your ipod touch in your workshop...
brunoip4 years ago
Great, I really like it
awoodcarver4 years ago
Very Handy I do remember when they gave these out at different places when you bought a few resistors ...My old one from RS is getting worn around the edges and is smaller then it was 30 years ago ...Or maybe it is my eyes???? going to make this a bit bigger so I can see it
gmjhowe4 years ago
Nice work! Im glad you worked it out yourself instead of 'copying' directly.
ChrysN4 years ago
Cool, I could definitely use one of these!
Bongmaster4 years ago
now that is handy :)
osgeld (author)  Bongmaster4 years ago
Yes it is :)