Hello and welcome.
In this last one we are going to talk about resisters and how you can identify for this story is in
good shape.
All of this is broken now if it is a good resister the marginal value must be within the range of the
rated value that measured value using an o meter or monthly meter that measure the value using an o
meter or a multimeter is a way to draw mind that is a store value in a circuit.
Another way is using the color band so we can remind the resistance of that is a store using that as
a store color coding as you can see each of these colors
indicate something.
So if the color came in the first digit as you can see for the four band resistor One two three four
or five and resistor each color means something if it Black was the first digit.
This means that the first value is zero.
If Black is the second digit then this means that the second value is zero same for third.
And here we have a multiplier and tolerance.
So let's say that we have this resistor.
Yellow means number four.
So we can write for up here
as you can see here.
The second color is purple.
It has number seven
so we are going to write several here.
The third digit here in this case is is the multiplier in a fourth band color code.
We have two digits and a multiplier and a runs value in five bands.
We have three digits a multiplier and utterance value.
So the third digit is not usable.
Here are the four band code.
So they are going to use the multiplier.
And the orange means 1000 so three zeros and the tolerance is this color which is gold.
And it will be plus or minus 5 percent.
So it will be 74 or 47 kilo because we have three zeros on with a tolerance plus 5 percent now in the
five band we will do the same thing.
The green is number five.
So we write five down here that Brown is number one as you can see here.
So write one down here.
And since it's five band code we will use the third digit which is black and it will be zero.
And the red for the multiplier means 100.
So we will add two zeros.
And here we have a brown which means 1 percent tolerance and you add 1 percent tolerance.
So it will be 51 three zeros.
Means kilo on that's it.
This is how to use color coding to identify that as a store value.
And this is the best way to identify as a store value inside a board without having to remove it.
Now to know if that resistance is working or not you have to measure the color using the color code.
Then you have to break out one of the two legs for that was a store from your board and measure it using
a digital multimeter.
And if these two values match the color coding value and the digital multimeter value if there was a
match between them this means that this was a store is working properly.
And there is no problem in it.
So what you need to know is that you need to find these store values and the color code and you need
to match it with the digital multimeter value if these two are the same means that the resistor is working
just fine.
Otherwise mean that you have a problem and you need to fix that problem.
Now one thing that you need to know is that you can't measure the resistance using as additional multimeter.
Why that is a store is still on board.
So you have to disassemble or disorder one of the two terminals of that resistor so that you can measure
it correctly because sometimes when you measure it while it's still on board you might end up measuring
it with other components connected to it parallel or Syria.
So this will cause a reading error and to avoid this we usually recommend this all during one of these
two terminals and removing them from the board and then you can test it or majority using dual digital
multimeter.
Now in order to cover this in more details these are some examples for a physical appearance of that
effective or defective resistor now as you can see this is how hard it is to lock when it is burned
out completely.
This is a slight burn out but yes you can still recognize the coloring.
Here you can three guys anything.
So if you saw it as this thought that looks like this in a board.
This means that this resistor is broken and you have to replace it.
So in order to measure out of the story using all this that is losing a digital multimeter you might
end up with three results open shorted or change value open meter deflection indicates infinite resistance
reading.
This means that that resistor is broken entirely.
And these two terminals are no longer connected together shorted meter deflection indicates zero resistance
reading.
This means that this resistor is now like our eye are connected and it doesn't have any value.
It's just zero resistance.
So it's like shorting two terminals are positive and negative and connecting them directly together.
Now the third but rarely happen incident is change that is the change in our resistance value.
Rare defect of a resistor measure the value is not within the range of the rated value.
So it is I think you're on with this story might measure it and read five kilo on resistor.
This is not a very common case.
Usually it's either open or shorted but it might happen.
It's very rare but it might happen.
So you need to know that it's there to make sure that before this thing at a distance you d all that
one of these two terminals from the circuit or you can disorder the whole resistance and twisted outside
then put it back or resold it to the board.
That's it for this lesson.
If you have any questions regarding the resistance these ask like you aren't able.
Thanks for watching.
This is Ashley from educational engineering team.