# Cool resistor calculator

388 Views 11 Replies 7 Participants Last post by  John Alison
Figures out the value for you, just click on the colors.

http://www.dannyg.com/examples/res2/resistor.htm

Deron.
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Hi Deron,

Quote:
 Originally posted by deronmoped Figures out the value for you, just click on the colors. http://www.dannyg.com/examples/res2/resistor.htm Deron.
After you have been playing with electronics for a while, you don't

need these tools anymore . You can easily read the color codes

directly from the resistor. However, beware the above only works

with 3 +1 (tolerance) color codes. The 4 +1 color codes have to be

read differently (although the colors still have the same number

values.)

Greets,

Reinhard
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Try this one, it does both: Calculator

Some of us really need these.
This one never fails. It's been about 10 years, since I learned that, and I can still remember it. Probably, one of the few things I still remember from school.

Boys= Brown= 1

Run= Red= 2

Over= Orange= 3

Your= Yellow= 4

Grass= Green= 5

But= Blue= 6

Victor= Violet= 7

Got= Grey= 8

Wet = White= 9

Chris.
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That must be the politically correct version; we learned:

"Bad Boys Rape Our Young Girls, But Violet Gives Willingly."

Anyway, once you remember the color-number relationship, just remember the third band is the quantity of zeroes after the first two digits. It's just familiarity.

It's no more dificult than remembering network punch-down colors, or the old/new phone wire color matching, or the number-letter groups on the phone pad, etc.
Thanks Larry, you beat me to it. That's the one I learned!

I've been an electrical engineer for 15 years now and although I work with surface-mount stuff now (no colors, just numbers on them), I still see my share of "old" resistors with the color bands. My problem is that I'm color blind and have a hard time getting the colors right by sight. I usually have to pull an ohmeter out.

Cary

PS. For at leaat 5 of those 15 years I designed PC video cards. It was always a big joke that the video guy was color blind
Hi Larry,

>Anyway, once you remember the color-number relationship, just

> remember the third band is the quantity of zeroes after the first

> two digits. It's just familiarity.

This is only true for carbon type (3+1 code) Metal usually uses

4+1 code, so you need to differentiate between the two. I think

the most problems beginners have is deciding which end of the

resistor to start on. The carbon type are easy, since the gold

and silver colors are not used for the first or second rings.

e. g.

- a brown black red nothing is a 1k 20% resistor

- a brown black red gold is a 1k 5% resistor

However a metal 1.00k resistor (c)would look this:

brown black black brown brown which is a 1.00k resistor with 1%

tolerance. Now you have the problem on what end to start looking

at the code??? USUALLY, there is a bigger space between the

brown brown then there is between the brown and the black. But

if you luck out and the manufacturer didn't do a good printing job,

you will need to measure the value.

A little mind teaser for all (the first one to find it out gets a virtual

reality dollar from me ). What value does this resistor have:

orange orange red blue violett green

??????????

Greets,

Reinhard
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Quote:
 What value does this resistor have: orange orange red blue violett green

Just to show how little I know, I would guess 6,703.3K Ohms.

It's been over 40 years since I memorized the color codes, and until now, that was about the last time I used them. The calculators are a big help to me.
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Quote:
 Originally posted by Lightningman What value does this resistor have: orange orange red blue violett green
332Meg, +/- 0.1%, but green isn't a 6th-band option. Only brown, red, orange, or yellow.
Hi Larry,

Quote:
 Originally posted by Larry Fine 332Meg, +/- 0.1%, but green isn't a 6th-band option. Only brown, red, orange, or yellow.
Almost. but not quite I chose this combo on purpose because

it isn't a common combination. You are correct on the value (332M)

and the tolerance. The green 6th band option is the TK im ppm and

would be 5ppm. While I'm not sure such a resistor exsists (that low

a ppm) it is defined as such The four non defined colors in the 6th

band are blue, violet, silver & gold.

Black: 200 ppm

Brown: 100 ppm

Red: 50 ppm

Orange: 15 ppm

Yellow: 25 ppm

Green: 5 ppm

White: 10 ppm

Since they totally screwed up the sequence in the 6th band, I too

cannot rely on memory when I need an >exact
enough the temperatur coefficent usually isn't that critical

@GlenC: Don't worry about it. Sometimes it can be really tricky and

many online calculators don't show reference to the 6th band option.

There are also a number of norm series for resistors like E6, E12, E24

E48 E96 E192. The higher the E number the more precise the value

you can choose.

For example:

E6: 1.0k 1.5k 2.2k etc

E12: 1.0k 1.2k 1.5k 1.8k 2.2k

E24: 1.0k 1.1k 1.2k 1.3k 1.5k 1.6k 1.8k 2.0k 2.2k

E6-E24 is the most common used series. I have never seen a E192

series resistor, but they can get as small as one incrediment (100

ohms and next one in the series would be 101 ohms)

Greets,

Reinhard
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You learn something every day...........

Not having any training in electronics, except one class in High School, 40 years ago, I was unaware of the six band resistors. My lay assumption was two three band in series..........would have been closer with parallel........

As a result, here is another calculator I found. http://international1.farnell.com/Se...lculator.jhtml
Looks as if a forum for resistor colour codes is required.
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