Skip to main content
Loading Explore guides…
Electrical Engineering Basics · Acedra
Home
Explore
Engineering
Electrical Engineering Basics
Sign in to save
Chat
If YouTube asks you to sign in, open the video on YouTube.
Watch on YouTube
Reload player
Transcript
105 segments
Copy
Hide video
0:04
All right, you guys. Welcome to today's show. So let's learn some electrical engineering, shall we? There are three terms that you need to now learn, in order to understand this stuff. And they are depicted as V and
0:27
I and Omega.
0:32
And I'm going to try to explain in a way that I think will make you understand all this stuff. Perhaps you learned some of this in physics in school. But today, I believe you will actually learn all this stuff, because if you do, you will be able to build and design some remarkable things later on in this series. And. All right, so to the left here, we have a battery. And this right here is supposed to be an electrical circuit. But the mental model that I want you to have is that
1:12
this battery, the plus side of it is this bowl of water. Okay. And the minus side is this pump right here. And this is a pipe. So let's say we start pumping here and we have a hole in the circuit like you see here. No matter how much you pump, you will not get any flow of water anywhere in this circuit. That makes sense, right? However, if this hole here does not exist, if we have a full circuit and you pump here,
2:02
the water will flow along this path here. And as long as there is water inside of this bowl, the water will flow. But as soon as this water runs out, the flow of water will stop. So that's quite logical. And electricity works the same way.
2:25
And the strength of this pump
2:29
is measured in volts.
2:38
And let's say that we have a propeller...
2:47
we mount a propeller here inside of this pipe. When we pump and the water will flow, this propeller will start to spin, right?
3:04
And let's also say that we connect this to a counter. So this is a counter (cnt). And each time... if this is the propeller seen from the front...
3:24
each time that this propeller makes a full circle, 360 degrees, we will increase this counter by one. And next time we increase by one, one and so on and so forth. If we were to count the number of laps. So the number of times it does a full circle, and per second, then we have a value of the strength of this flow of water, right?
4:08
And this strength of the flow.
4:11
So the... the number of laps that this propeller will do per second, that is measured in Ampère,
4:25
or “amps” as it's called in America. Okay. So the voltage
4:38
has only meaning if there is water here. If this water bowl is empty, we can put 10,000 volts or whatever on this pump, but there will not be any flow of water, so this propeller will not spin.
4:58
So the strength of this pump, the voltage, that is more of a potential.
5:08
In order for the voltage to be an electrical current, measured in Ampère, we need to have an [enough] loaded battery, so water in this tank,
5:21
and we need to have a full circuit. There can't be any holes or anything.
5:29
All right? So what if we were to
5:35
shorten this whole pipe system
5:42
when we still have the same strength of this pump? Let's say we had 1.5 volts before and we still have 1.5 volts, so that’s the strength of the pump, and we have this propeller right here. What will happen with the flow of water in this case if we compare it to the longer distance? Well, in order to figure that out, I want you to consider one thing. If you have a soda mug from like the hamburger restaurant or something
6:27
and you have a straw that you drink this soda with.
6:32
If the straw is two inches long, it will be very easy to drink this stuff. But if it's like two yards long,
6:45
then you will need to suck very hard on it for it to give any soda. And the same is true for this pump since this pipe system is much shorter than before, with the same power of this pump, this propeller will spin much faster.
7:09
And maybe the flow of water becomes so intense that this propeller will break.
7:19
So we need to be
7:23
we need to consider that when we build this kind of stuff, that all the components that we add to this circuit, if we put too much power, too much power on it, it will break. So we need to be able to handle that somehow because we cannot always count on
7:50
creating a long enough circuit. We never can do that. Actually. So how do we solve this problem? We need to some somehow artificially make this longer. And we do that by using one of these small things. It's called a resistor.
8:23
So a resistor, when we make a sketch for our circuit looks like something like this, and this explains it quite a lot. So when we put electricity through this resistor, it will take a longer path or it will be built in such a way that it has the same effect.
8:55
So even if we have the same power of the pump, if you had the same voltage and the same distance and we connect one of these resistors, the amperes, the amps will go down
9:09
and this resistance is measured in over.
9:15
And I'm not going to go into any math here, and I'm not going to describe how to calculate all of these values, because that's not the important thing here. The important thing is that, you know, the difference between these three things,
9:35
that the voltage is the strength of the battery of the.
9:40
The Ampere is the flow of water.
9:45
And usually in most cases, or at least in many cases, you have the same strength of the battery. It's often 1.50, for instance, and in electrical circuits it's often 3.3 or five floats.
10:03
So what we can change is the oh, the resistance. And that way we can lower the arms.
10:19
Alright, so welcome back. When you do a sketch for an electronic engineering, all the different components have different symbols and a battery. Looks like this. So
10:40
one long line and one
10:45
kind of one. And then you have two connectors like this.
10:51
So the side with the long line is the plus side and the tinier line is the minus three. And if we were to call it a
11:07
light of some kind, for instance, and indeed
11:15
it looks something like this
11:21
with some beams going off from it. And as you can see, this is formed like an arrow. And that is because it needs to be connected to the right side. Food speak. So this the circuit or this component will only left and does the electricity go one way, so to speak? So if you turn this on the wrong side, it will not let the electricity through. And if you were to connect it like this, it would be too much power running through this LED. So it would probably break. So as we talked before,
12:17
we need to connect a resistor
12:21
so we eliminate the current through this circuit and. Right. And if we were to connect without the through system
12:36
and you connect the two sides of the batteries like this, this is called a pure
12:49
circuit and you should avoid this. You should always avoid this because the fluid, the flow of electricity will be far too high. So you will damage the battery and possibly other components, but also the battery would run out very fast because there is no resistance or very little resistance. And when you create things, there are basically two ways you can do it. If we have, let's say, two of these lamps, these LEDs, and we connect them like this.
13:44
This is called a serial connection. And then when we connected left this
13:56
both of these lights will shine
14:01
as much as if we only had one of these connected. Basically. But the battery would run out faster because of this.
14:13
But we can also do a parallel connection
14:19
which would look something like this.
14:23
So we have the first one
14:31
fixed and then we connect the second one, something like this. So the one side of the LCD lamp is connected to the left side, and both of these are connected together to the plus side and same for the minus side. This are a parallel solution
15:05
and in this case the battery will run out as fast as if we only had one of these left basically. But both of these lamps will only shine with half the intensity.
15:24
So these are two different ways we can connect these things. And why does it behave like this? Well, this is because the lights and the electricity will always try to flow through the path of least resistance. But in this case, we have two possible ways for the circuits to go full circle, so to speak. It can go this way
15:58
and it can go this. So the electricity will work. How could I turn? I do not work where it is. The electricity will go. Half of the electricity will go through this one and half of the electricity through this one. But if we connect in this series and it's
16:31
it works differently.
16:35
So there's another thing which is good
16:42
is let's say we have
16:46
a connection that looks like this. So we have one of these lights, the
16:56
and so this before we have another one here but
17:05
over here we have a resistor. So in this case, this luck will not shine at all
17:17
because all electricity will take the power for the persistence, which is through the first light
17:25
and nothing will go this direction because this has much higher resistance and it always tries to avoid the resistance.
17:34
However, if we were to disconnect this life, then the other life will go on because now we only have one way. We have to go through this one with the resistance. So using this technique, you can decide what path the electricity will take. And this is the basis for all the logical circuits, like in a CPU.
18:09
So guys, welcome here. So this is a transistor. A transistor is one of the most important components in electrical engineer, in computer science.
18:27
And there the components that we have looked at this for as two connectors each, both the battery and the resistor and the LED. But this has three connectors and this works like a switch. So let's say we have a battery here or this is plus and this is minus and we connect
18:55
the circuit like this and let's put an LCD here.
19:01
So let's do something like this.
19:06
We let's do something like this. And, and of course we need to have a resistor here as well. But let's not focus on that right now.
19:22
So if we were to connect this circuit, this lamp will not be left in this case
19:34
because this transistor works like a switch and currently this switch is disconnected.
19:43
However, if we take this metal leg right here and we put to power, but if we put electricity on this leg right here, let's call this signal a
20:00
we we don't need to put a lot of electricity, just this kind of signal. Then this light will turn on
20:10
and we can do that either by connecting this to somewhere else, but we can connect it down here
20:20
and in this case, and this transistor would turn on. But the electricity would go this way. So it will still not go elsewhere. So we can fix this by adding a resistor like this, because the really even though this path contains a resistor
20:54
and a small amount of electricity, it will go this way and this will activate this transistor, which means that if the electricity will start flowing like this and the light will be turned up, and if we wanted to disconnect this, we could just let it flow like this, or we can connect to the plus side or something like that. But the important thing is that if we have an electricity flowing through the leg and that in turn creates a full circuit,
21:36
then this will activate and put electricity this way. And this is the most important
21:46
concept because then we can make if statements.
21:53
So we can create things
22:00
like you get. It's also called
22:10
logical gates. And one symbol for one of these looks something like this.
22:20
It has two inputs A and B and one output, which often is just depicted as out. And this gate works like an if statement like this. So let's say we have a function which returns a boolean. So true or false, let's call this gate. And we have two parameters which are also booleans. So we have pool a
23:06
and B
23:14
and it's a, and they are both true.
23:23
In that case, we return through. Otherwise we return
23:39
false. And using gets like this, we can combine them and create any logic. We can create an entire CPU just with gates similar to this one.
23:57
And this. We can make a table out of the possible values. And when we talk about logical great gates, we usually don't talk about Booleans. We often say that zero is equal to false
24:15
and one is equally true.
24:19
I used booleans here because I wanted to show that they are one bit
24:25
of information which all right, So if we're going to make a table out of the different results of this gate, it will look sample this. We're going to have the a input and the input and the output. All right. So if A is zero and B is zero, that means that's the out is zero.
25:08
If A is one and B is zero, or if A is zero and B is well,
25:18
the result is still zero. Right. But if both is are ones,
25:27
then the result would be one. And this is called
25:41
an and gate and you can see that here in the describing it statement
25:50
so it works same as this and C so if A is true and B is true then the result is true otherwise false. And same here. If both of these inputs are one, then we have a one as an output. So this is the end gate
26:30
and our next gate looks almost the same. It still has this shape, but instead of making a line directly across these two, we're going to form it like Oh and then we have the two inputs A and B and we have the word output. But
27:01
and the code for this is the same as the other one, except that we have an or here is that
27:15
and so this is a logical
27:29
or gate. So if both of these inputs are zero, the outputs of zero,
27:38
if one is a zero and the other one is a one, then the result will be one in both cases. And if we have both inputs as one, the result would be well. So this is the direct opposite of the hand gate. So are you starting to see the pattern here? We have the electronic versions of these if statements. So if we can do this statement that takes two inputs and produces an output,
28:18
then we can build any type of logical circuit. And there are a lot of different other gates as well. But these are the two most common, I would say the most important ones. So I hope you like this episode
28:46
and please like and subscribe because we are going to build really cool projects moving forward.
28:53
So thanks for watching. Thanks for today.
Here to help you learn
Sign in to keep a private conversation with your course tutor.
Ask me anything about the material…
Sign in to chat