RSD Academy - The Resistor Color Code

hi welcome to our SD Academy I'm Bob Duhamel and today we are going to talk about the resistor color code now you don't need to have any calculator website smartphone app or slide rule or anything like that to calculate resistors all you need to do is remember a simple mnemonic and that mnemonic is better be ready or your great big plan goes wrong yes I know there's another one but we're going to keep this video family-friendly so each one of these represents a color in the color code and those are black brown red orange yellow green blue purple gray and white and then each one of these colors represents a number and as you see black is zero Brown is one red is two three four five six seven eight and nine and we'll start with resistors that have three color bands so let's just draw a resistor up here I'll use black for my bands but we'll make this work so here are the three color bands now there's probably a fourth color band which will be either gold or silver but we'll talk about that later that would be the tolerance whether it has a tolerance of 10% or 5% or if there is no band that that would be 20% but those are pretty rare but let's just talk about the value of the resistor so let's just pick a resistor at random and calculate its value so here I have a resistor you can't see it but I'll write the colors on the board it is brown black and green so the colors are brown black and green so these are brown is one black is zero and green is five so that is 105 ohms right well of course not so how does that read well it's very simple the first color is simply the first number the second color is simply the second number but the third number is the number of zeros to follow now some people will say this is the multiplier and say that you multiply it by tens times this number doing scientific notation others will say that this tells you how many places to move the decimal point it's simply the number of zeros so this is one zero and five zeros so that's pretty simple whoops got to get that in the right place there one and zero and five more zeroes simply 1 million ohms or 1 megohm let's pick another random resistor and do that one okay this one is yellow purple red a fairly common one yellow purple red and let's not do this by looking at the chart let's start doing this from memory well throw out the better because we start counting from one so let's do the mnemonic from be ready or your great big plan goes wrong so yellow is be ready or your that's for purple be ready or your great big plan that's seven and red is be ready that's two so that's four seven two which is four seven and two zeroes so this is four thousand seven hundred ohms or four point seven K let's do another one here we have purple green black purple green black just remember that black is zero so this is purple which is be ready or your great big plan so that's going to be seven green is be ready or your great that's five and then black is zero so 750 ohms now it's seven and five and the number of zeros so that's zero zeros so this is 75 ohms shall we keep going here we have yellow colors a little I'm sure that's not blacks it's got to be purple yellow purple orange that's similar to one we just did but another common one yellow purple orange so that's going to be yellow be ready or you're for purple be ready or your great big plan that's seven and then oranges be ready or it's three so that's four seven and three zeroes or forty seven thousand ohms or 47k let's keep going here we have brown red orange so Brown is B which is one ready be ready that's to be ready or that's three one two three that's one and two and three zeroes so twelve thousand ohms now let's try another one so here we have a little pack of resistors red red black orange brown now what do we do with that that's too many colors well it's pretty simple actually it's red red red red black orange brown red red black orange brown let's forget about the last band for now now we have four colors giving us the value of the resistor instead of three with or without that we know this is a precision resistor without a fifth band we know it's a one-percent resistor but sometimes in fact more often than not now they also put a brown band on the end a fifth band telling us this is a one percent tolerance resistor so we ignore the last band and just read the first four and it works just like the three band resistors so we have red red black orange so that's going to be B READY that's to be ready to black of course is zero orange be ready or that's three so we have two two zero three same exact thing to a to a zero and then the number of zeros so this is a two hundred and twenty thousand ohm resistor let's do another one of these there's another one let's get it oriented right here blue gray black brown brown okay so once again we have five colors we ignore the last one blue gray black brown brown blue gray black brown brown so let's start off with the blue be ready or your great big that's going to be six gray be ready or your great big plan goes that's eight black is zero brown is B that's one so we have six eight zero and one zero so six point eight K or 6800 ohms let's do another while we're on a roll the next one we have here is brown yellow black black brown whereas it brown black black yellow brown you know these should be printed asymmetrical so I know to start at the side closest to the end but this particular resistor I don't know if you can see this in the camera stick that up there fairly close but they're pretty symmetrical I really can't tell which end to come from so these are either brown black black yellow brown or brown yellow black black brown let's just figure them both out and see what we get so start out with brown yellow black black brown that's going to be one yellow be ready or your that's four black zero black zero and forget the last Brown that's going to be one four zero and zero zeros so 140 ohms could be could be but I kind of doubt it let's flip it over and do it the other way that's going to be brown black black yellow brown ignore the last Brown that's going to be one zero zero yellow be ready or your four that's going to be one zero and zero and four more zeros one two three four so it comes out to 1 megohm well fortunately these happen to be in the package and low and behold that's what we have right there is 1 million ohms so we do have we were able to fit well we couldn't figure out which is which what we do see that it is 1 million ohms so should be easier to read than that might have to pull out your o meter some time just to tell what these are but no I can't tell which way to read these that's uh that's a manufacturing defect so got a watch out for that now let's talk about tolerance for a minute if you have three color bands you might have a fourth tolerance band if you have no fourth tolerance band it's a 20% resistor if you have silver and that band is usually offset so there's a gap between them that's silver that's 10% and gold which is by far the most common these days is 5% so it just tells you what the tolerance of that particular resistor is and what range it should happen to fall in so you might be asked some time to calculate a resistor and you might need to know what range of Tolerance it might fall into so let's come up with a imaginary resistor let's say 10 K so 10 K what's that going to be brown black and orange so we got that right brown one black zero and orange B READY or three zeros then we have 10 K so let's say there's a gold band on the end that means it's a 5% resistor so we have 10,000 ohms 5% tolerance the question is what range of resistance might this really be with a 5% tolerance well let's pull out our trusty calculator here and we take our resistance which is 10,000 and we multiply it by 0.2 0-5 and that gives us 500 ohms so that's going to be plus or minus 500 ohms so this resistor could be anywhere from ten thousand five hundred ohms the upper limit to nine thousand five hundred ohms the lower limit so to calculate your tolerance you take your resistance multiply that by point zero five to get your plus or minus number then you take the resistance and add that number then you take the resistance and subtract that number that will give you the range that that resistor might fall in so this 10 thousand ohm resistor may be anywhere from nine thousand five hundred ohms to ten thousand five hundred ohms let's do another one I don't actually have an example of this so I'll just throw up the numbers red red gold gold for the third one yes let's see what this is that's going to be B READY that's two and two and gold tells us to move the decimal point one place to the left unfortunately I can't do it as simply as number of zeros but everything can't be that easy so gold means move the decimal point one place to the left so red red gold would be to to move the decimal point there that's two point two ohms let's look at another one how about yellow purple gold that's going to be yellow be ready or you're for purple be ready or your great big plan seven and then gold means move the decimal point one place so that would be four point seven ohms now what if we want an even smaller resistance let's do the same thing with silver red red silver that's going to be to to move the decimal point two places remember gold gives you bigger numbers than silver so gold you move at one decimal place silver you move it to so for makes the number smaller so red red silver as 0.22 ohms and if we do the other one we just did yellow purple silver is going to be be ready or you're for be ready or your great big plan seven and then silver one two point four seven ohms let's just come up with some numbers for practice and then call it a day how about red red red not too uncommon that's going to simply be to two and two zeroes how about let's do a four color one how about red red black brown that's going to be two to zero and one zero so notice that red red red on a three color one let's say that was a gold over here so it's a five percent resistor so red red red is two and two and two zeroes but with a one percent resistor that becomes red red black brown which is two two zero and one zero so those are actually the same resistance so remember if it's three numbers let's come up with another one let's do a how about this how about orange red red that's going to be B READY or three be ready to and two zeros how about green gray and blue I'm just making this up you would probably not find a resistor of this color code but for practice let's do it Green is be ready or you're great that's five gray be ready or your great big plan goes that's going to be eight and blue be ready or your great big six that's a lot of zeros there that's going to be five and eight and one two three four five six that's what it is 58 million ohms I doubt it but that's what it would be if it was green grey blue one more just for the fun of it how about white and yellow and purple that would be be ready or your great big plan goes wrong that would be nine yellow be ready or your four and purple be ready or your great big plan that's going to be seven a lot of zeros again but this is just for practice that's going to be 9 & 4 & 1 2 3 4 5 6 7 yeah 940 million probably not but that's what the numbers would be let's just do one more realistic one very common combination how about yellow purple and green so that's going to be B READY or your for purple be ready or your great big plan 7 and green be ready or your great that's 5 that's going to be 4 and 7 and 1 2 3 4 5 sub B 4 point 7 make and that's a realistic number that I would not be surprised to find a resistor with the 47 or 33 or 22 tend to be common numbers that you find in resistors so again just as a reminder just remember better be ready or your great big plan goes wrong and when you look at the number just start counting with B be ready or you're great that's 5 be ready or your great big plan that's 7 be ready or your that's 4 great be ready or your great big plan goes that's 8 and you can use that to calculate any resistor just remember if there's three colors it's number number number of zeros if it's four colors it's number number number number of zeros a couple of last things I need to say before we sign off here is that sometimes you'll find resistors with the resistance printed right on them that sure makes life easy other times you might see something like this here we have a resistor with just some numbers printed on it now since there's four numbers a bit that's a precision resistor that it's a 1% and you read it just like the 1% resistors this would be four seven zero and three zeros so that would be 470 K this video is about the color code and this is kind of rare but you might run across resistors with the resistance printed right on them or with the code printed on that reads just like the color code but it's numbers instead of the color code thanks for watching and be sure to hit that thumbs up down below if you think this video was useful and informative and be sure to subscribe and hit that Bell button when you do subscribe to receive a notification when we put new videos online and our SD Academy is a free online vocational school if you'd like to study electronics technology and prepare for a career as an electronics technician you can take our free course at our SD Academy net and help us put these courses and videos online for free you can pledge your support at patreon.com slash our SD Academy you can also help us by sharing these videos on social media and linking to our SD Academy net and a big thank you to our patrons and sponsors you are making this possible

Channel: RSD Academy

Views: 111,797

Keywords: Basic electronics, electronics school, free online classes, electronics classes, learn electronics, learn electronics technology, Resistor color code

Id: 6HqvPsiKStw

Length: 19min 52sec (1192 seconds)

Published: Tue Jul 10 2018