Okay, and on this slide, I show you several sizes of fixed value resistors. And they range from three watts down to one 16th of a watt. Now, I'm going to define what a watt is just here, I'm going to just show you the formula. Right when you would take my circuit analysis course, we'll get into a deeper but power of a component, which will determine the wattage rating equals the voltage across the component. In this case, the resistor times the current flow through it and current is abbreviated By I, so that's current. Alright, so for instance, if I make a calculation here and I say that the amount of power that's dissipated by the resistor and I'm using specifically resistor here because that's what we're talking about is a half watt than the component or the or the wattage rating of that of the resistor that I should place inside this circuit would be a one watt resistor because what we want to do is we want to overcompensate it.

So if I calculate a half a watt, I want to make sure that the component that I put in there or the resistor value that I put in there is double lat or greater and greater is okay too. But But We would like to see at least two times the calculated value. Okay, the next thing I want to speak about is the colorings and lonnis resistor pictures, you'll see that I have four bands and you can count them. All right, the first digit is closest to the left. You'll notice that all these resistors if you look at them, and I'm going to clear the slide off, but I just wanted to emphasize that is closest to the left, that is the first digit. Okay, now, on a four band resistor, and as I'm talking I'm going to clear the slide off on a four because we have four and five resistors Alright, so on a four band resistor, you'll notice and this one's very pronounced, that's gold.

This is gold, gold, gold, gold, gold, they're all right the last band or the band all the way to the right is the tolerance band. Very hard to get a period with this okay is the tolerance band and I abbreviated tolerance right there okay. The tolerance band is the specification on the resistor. In other words that resistor may or may not be may not be exactly the public value of the resistor which is determined in this case by the front three bands right there. All right. So there's a tolerance plus or minus 5% plus or minus 10%.

Plus or minus 2%. Okay, we'll see how to calculate that in upcoming slides. But that's the tolerance band. The tolerance band says, Okay, I've got this value resistor, the upper limit can be as high as this, and the lower limit can be as low as that and we'll see as we go on. All right, so now let's stop here and go on to the next slide. Okay, on this slide here, we're going to introduce the color code.

And what I've done is I've given you a little bit of a poem to try to remember the colors. And the little POM a little saying is right here. big boys race out young girls, but violet generally wins. Now, the first letter of the of this poem represents a color. And what you have to remember is that we go from a dark numb dark color, which is black, up to a bright color, which is white. All right.

And the first letter of the first word in the poem is the, the first letter of the color, for instance, big is black boys is brown. All right, big. Black represents zero, boys brown represents one race represents red and it's the number two, our equals orange. And that's the number three young represents yellow. And that's the number four For girls represents green, and that's five, but represents blue and that six, violet is violet. And that represents seven and generally equals gray.

And that's eight wins equals white, and that's nine. So again, we go from a very dark color to a very light color. If you can remember that poem. it'll, it'll make life easier for you. All right. So that's all I'm going to say here.

I just take a look at this and try to remember it. And we're going to go on to the next slide. Okay, on this slide here, we're going to see how the colors represent the value of the resistor. And in this slide here, we've got a four man resistor up here. And then we've got a five band down here, or right now we're just going to look at the four band. Now the first thing I want to mention is We have to know where the first digit is or what color represents the first digit.

And if I look at this resistor, I want to find the group of colors that are to the left of the resistor. So by looking at this resistor, you can see the group to the left is these two here are those three, they're all right, where the most left color. In this example, green is the first digit. All right, now, let's go over here. And if you look at where it says colors, if you remember back in section one, I gave you big boys race out young girls, but violet generally wins and we start from zero which is black, and we go all the way to white Which is nine. All right, and again, I said earlier, if you don't see that, go back and review Part one.

So looking at this again here, the first band of color is green and what does that represent? That represents five. The collar to the right of that in this example, blue represents six. And on a four band resistor, the third band is the multiplier as I show you here, that is yellow, and that represents 10 K. All right, so what do we have? We've got five which is the first band color. We've got six, which is blue, and we have a multiple wire of 10 K, so I can multiply that by 10 K. And previously, I've mentioned this k equals one k equals 1000.

So I can do this five, six times 10 times 1000. What does that equal 560123 zeros ohms 560,000 ohms or 560 because k equals 1000. I can have 500 to 60 k ohms. All right, again, all I'm doing is looking at the colors All right and represented that color represents a certain number. If it's a four band resistor, the first band is the first digit. The second band is the second digit.

And then I have a multiplier and I multiply that out. That's the value of that resistor. Now I've cleaned off the slide and I want to talk about the tolerance. Now on a four band resistor, with a four band resistor can have four tolerances, 10% 5% and 2%, which is right here. If you'll notice, the fourth man on a four band resistor right here is the tolerance man. So if I have four, a four band resistor or a resistance that's represented by four bands of color, I can have a to five or 10% so The fourth ban can either be red, gold, or silver.

Right now, the posted value or the colors that represent the value of our resistor that we're explaining right now is right here. 560 ohms 560 k ohms plus or minus 5%. All right, that plus or minus 5% is an upper limit, and I'm going to abbreviate that ul and a lower limit. All right, so that resistor can go 560 k ohms 5% above and 560 k on 5% below and I'm going to show you how to get that I've got a blank slide coming up. We're going to go that I'm going to go through the derivation on that. So let's go over there now.

Okay, the value of my resistor as we know is 560 k ohms or 560,000. Homes. All right, plus or minus 5%. So what do we need to do first? First, we need to find 5% 5% of what of the value of our Alright, so how do we do that? Well, we take the 5% And we change that into a decimal.

How do we do that? Well, if I've got 5%, what do I need to do? I need to move the decimal two places to the left. All right, so when I move the decimal two places to the left, I get zero dot. And it's very hard for me to show this arrow. Like I said, I'm buying a new tablet for this.

So bear with me. Zero dot and my dots right there are my decimal points right there, but we don't see it. Zero dot 05. All right. All right. So now let's clear the slide.

So what I've done now here is taken 560,000 ohms. I multiplied it by 5%. But here's my data. equivalent zero dot 05. And when I do the math, I come up with 28,021 28,000 ohms. So now, if you look, I got 560,000 ohms.

And before we said plus or minus 5%. Well right now we know that that's plus or minus 28,000 ohms. Let me get the old signs here. All right, so now I need to find my upper limit ul. So my upper limit equals 560000 plus 28,000 ohms. And we'll fill it will fill in, we'll do the math and fill in the numbers in a minute.

And my lower limit equals 560 thousand ohms. keep forgetting neon sign here minus 28,000 Arms. And that's going to be my lower limit. So let's see what it is. And all I do is subtract 28,000 from 560. For my lower limit, and from my upper limit, I add 28,000 ohms.

Alright, so let's do that. Okay, so here we have 560,000 ohms plus 28,000 homes, that's my upper limit, because when I did the calculations, 560,000 ohms plus a minus 28,000. Right here, what I show you right there, all right, so my upper limit would be 588 k home, because I take 560 and I add 28,000 to it, and my lower limit is going to be 530. 2000 ohms or 532 k ohms right there. So I have an upper limit and a lower limit, again, my upper limit will use right here, my upper limit is 588 k ohms. My lower limit is 532 k ohms.

So when I measure this resistor with a meter, some sort of meter, if the resistor has a value between 588 k ohms to a lower limit of 532 k ohms. That resistor is good because it's in plus or minus 5%. Okay, let's look at another one. And I've typed this one out for you. All right, we have our resistor right here. And we we look for the body of colors.

That's closest To the left, here they are. And those colors are brown, black, red. So now if I look, the first digit is brown. If I look at my man one, right there, it's brown that represents one. Then second digit is black band two right here, that represents zero, there it is right there. And my third band, which is my multiplier is red, which is right here.

And that represents 100. My tolerance span which is the fourth band here, which is silver, and that tolerance span is plus or minus 10%. So now I just go through the math. The first significant digit is one, the second is 10. And my multiplier is 100. So I do 10 times 100 that equals 1000 ohms.

My tolerance is plus or minus 10%. Okay, and I show you that right here. Okay, first digit brown one second digit color black zero, third digit color red is 100. And so I multiply that the fourth digit tolerance silver plus or minus 10%. So now I take my tolerance, which is 1000 times one 1000 times 10%. All right, I move my decimal point two places to the left, so that gives me a point one.

All right, so 1000 times point one is 100. Again, there's my desk, my percentage and his my decimal equivalent move the decimal places to places to the left. Okay, now my upper limit the value of my resistor plus 100. My lower limit 1000 ohms minus 100 ohms is 900 ohms. So if I measure this resistor and the low end it's 900 ohms to the upper end, which is 1100 ohms. If I, if I'm within that window, the resistor is good.

The only challenge here if you don't really understand is we have to take my percentage my 10% right here and we have to change it to a decimal. two places to the left. Okay, two places to the left.