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Hello, how are you, welcome to start the eby, you are Iberian,
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continuing with the basic electronics course from scratch, we are going to start with the famous Ohm's law and with two circuits we resist,
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let's look at what the d hondt law
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consists of, it is a very fundamental law in the entire part electronics
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without it nothing that we can be talking about can be fulfilled
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here we can observe this little triangle this triangle is equivalent to the d hont law
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if you learn this little triangle it is easy for you to solve it without being an expert in mathematics or anything like that
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in In case you have a little difficulty
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clearing voltage from current or resistance, let me explain. I have voltage,
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voltage is equal, I plug voltage to cris equal and I will return,
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that is, current times resistance,
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a volt is equal to an ampere
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x a UFO,
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that is what This means that Ohm's law
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continued to increase resistance,
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I am increasing voltage because they are directly proportional
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and in the same way that current increase I am going to increase the voltage,
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there is one thing very clear and we must
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be specific about something, there is no
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current without existing voltage or voltage without existing. current, the two are
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proportional, the two are linked. You cannot say that it is true that the circuit is generating a thousand volts
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and zero amperes. No, no, it cannot be done.
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Let's remember the drawing from the previous course in which we said that the electric current was here.
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Obviously, if there are electrons, there will be. force at its output
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if there are no electrons it is impossible for there to be force now there are projects in which a lot of voltage is generated, for example the tesla coil
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side of nate is what it generates is a magnetic induction of a primary coil and a secondary one and that raises the super high voltage
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generating sparks but this current is very low obviously depending on how it was designed
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all the current is so low but the voltage is very very high but it has to exist they are linked together
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suppose that now we are going to clear current to clear current
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the ideal way is what is multiplying, it happens dividing or if we don't see it here in the little triangle we cover
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and since it is equal b
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About what is left here r
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Let's solve for r
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We cover r since it is equal to ab
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About the intensity
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and here we have the three situations of the same fundamental equation of Ohm's law,
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please, you have to memorize these equations
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very well because absolutely everything in electronics depends on this, regardless of whether it is basic electronics medium electronics advanced electronics
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analog digital power microcontrollers whatever it is based on this law the famous law of o
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you are going to see later videos in which we would be analyzing laws
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kitshoff lv-ca the sk norton thevenin and everything is based on the famous law of ohm
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ohm's law tells us the following in a practical example
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Let's draw a battery
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this symbol indicates a voltage source this voltage source
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when you don't start reading to do a little more research there is a type of sources that are dependent sources and independent sources
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dependent sources are those that depend on the current of the voltage
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if lowers the voltage which increases the current or if the current increases the voltage
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an example and others are independent sources
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an example would be a regulator a voltage regulator
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regardless of the current it is consuming the simple regulator its terminals will deliver a specific voltage an example Of course, it is a 7805 regulator
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that is powered by, for example, 12 volts, its
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regulators receive 5 volts and even though the load consumes 5000 before God, it always has 5 volts,
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it can consume one ampere and it always has its 5 volts, that is, Its edge does not
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differ in voltage or its voltage does not depend on the current.
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An example of an independent source is an
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inexpensive adapter that we find on the market.
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It has 5 volts. We connect it to a circuit and it automatically drops to 4 or drops to 4. 3
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then the voltage depends a lot on the current in this case we can look at types of sources dependent sources and independent sources
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for this
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course that we will be developing usually I like to draw this type of symbols
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indicating that this is a source I can use this symbol or can I use
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This symbol,
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this symbol itself indicates a battery, the battery can be a charger battery, an adapter,
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logically a battery, since it is a battery, for example, of a motorcycle, a
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car, a 9-volt pyrite, an edu battery
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, any type of batteries that you have, but I always use any of these two
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symbols either this symbol I don't know if it will be reached on the camera will place it
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These are the two symbols that I always use so you don't know to worry if you are a symbol or this symbol for me
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indicates that it is a source voltage can be battery charger battery adapter or any element that enters
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continuous energy
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in this course for the moment we will not be working with alternating currents or voltages we will always be working with
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direct currents or pure direct currents explaining Ohm's law a little more on a practical level As I had already mentioned,
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a typical example is the following,
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suppose that you
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A heater or so-called shower that heats the water for daily cleaning, a bath,
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this shower has an
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internal resistance
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. When this resistance you connect it to the alternating network, that is, It is already connected through the electrical wiring system.
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When you turn it on, it is electrical fluid or the bulbs. The luminaires try to lower the brightness a little
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because the lower the resistance,
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the lower the voltage. This resistance is very low, so I tried to make it a short. Here they are seen at lower
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resistance, the current increases and if we see it here at lower resistance, the voltage
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also tries to decrease, it gives the impression that a short is being generated, that is, as if the voltage is trying to fall.
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In these struggles, the two principles are presented. If I
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decreased the resistance or the opposition
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will generate
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greater current flow,
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typical example,
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the shower was turned on and if the electrical system is miscalculated, suddenly the protection system of our home
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called break is triggered, then you are taking a bath and suddenly it stops. The protection system was triggered because the current increased,
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the resistance increased the current and the protection system was at its limit.
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Suppose the showers were 40 amps and the break was 40 amps. By logic, they detected or 40 pesos and the
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device was triggered in this case. We can clearly observe the law of or where example in real life.
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Let's now look at what set circuits are and
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look at how they are calculated, how they are added, how they are operated and how they are going to be measured. At the end of each video,
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I will try to explain everything in a practical way. what we are going to place theoretically
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here we have the first circuit called series circuit the series circuits as its name says is one component
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behind another
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we have the first symbol that we are going to be using this symbol indicates
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resistance electrical resistance at the end of a resistor
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I connect another resistance
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to the end of another resistance I connect another resistance
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as we can see
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There is only one path of circulation of the free accord so here we have
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A voltage source with three resistors connected to each other
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at the end of one begins to the other and so on
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and the electric current
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tries to circulate from positive to negative.
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That is the way in which the electric current is circulating according to international nomenclatures.
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To analyze this circuit we need to do the following:
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we are going to
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polarize all abyssal means placing the way in which the current entered, use the plus 10 - in each component
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this depends on the position of the battery
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so I have more here placed more
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more more more
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less more less more meters
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this means
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that when the current enters like this
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the current but the polarization is always like this
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if the current enters the On the other hand, polarization is like this.
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What is polarization for? To analyze the circuits later
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to know where the current goes. I can have an xy circuit. If I don't know where the current goes, I can't
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analyze it. I can't know if the current goes up. or downwards, I can't know if how I'm going to polarize it, I can't know
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if I'm going to add it, I'm going to subtract it, so it's vitally important.
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This is the polarization of the circuits,
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the first law, as I already mentioned, has only one path. The first rule that the circuit tells us is
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that I am going to
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symbolize the current with a and the current is the same
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in any part of the circuit,
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that is, If I measure the current here
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I am going to measure the same
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the friend here I am going to measure the same I measure here I am going to measure the same that is if I disconnected
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each of these connections
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where two or more components are joined is known by the name node then here I have
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a node
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that's why in telecommunications it is said there we have a
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telecommunications node not a point of intersection of several elements that radiate the signal as such in this case we have
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1 2 3 4 knots
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these
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angles that I make here are simply by design This is a cable
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This is a cable that connects the source with the resistance to the source with the resistance in the source with the assistance of the
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source with the resistance Now that we look at it practically we are going to realize how this system works
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. What we have here is a series circuit now what happens with the voltage
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I have a voltage an example I am going to place three 10 kilo omnium resistors
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All the same 10 kilos as I did in the analysis of the color code they are equivalent to the following color
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for example it is brown
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Black
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Golden orange
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that is the color code of 10k
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brown one black 0 orange 3 1 2 3 years if I do not divide by a thousand
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I have 10
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kilos
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That would be the resisted value and the color code of this equipment that I am drawing on the board
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the voltage at A series circuit is divided by each component.
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For example, I have a 15-volt source.
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What that 15-volt source does is that each resistor takes the voltage that corresponds to it depending on its resistivity.
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In this case, there are three equal resistors by logic without applying There is no equation and without doing any analysis
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I have 15 volts and internally it is being divided,
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which means that each resistor corresponds to
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55 and 5 volts.
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This is a very simple way to analyze, for example.
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In December seasons, sets of lights are purchased.
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Quite a few, especially in Latin America.
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We have
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so-called Christmas series, that's why they are called that way and it turns out that if one light bulb burns out, about 20 or
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40 light bulbs or 100 light bulbs go out, yes, because if I disconnect a single light bulb,
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the circuit remains open, the current as it no longer passed through one light bulb. It will not go through the rest of the bulbs,
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so the circuit is completely
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disconnected. That is the reason
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why in the series circuits, a bulb burns out. You have to take it out and start testing each one of them until you find that it
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is burned out and when you He already tests it and installs a new one. The circuit completely works again.
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Total resistance is measured in a different way.
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I can place it. I know that here I have 10 k, 10 k, and 10 k.
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So the total resistance of the sum
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is completely bone.
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We already had the second law. said that the voltage of the source is divided by each component
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and the third thing that I just said is that the total resistance is equal to the sum of the resistances.
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What does the total resistance mean
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in our home? Electrical companies are not really interested. What we have in our home, because of
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environmental policies,
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they say consumption,
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energy savers
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, don't turn on the light for so long, etc., but those are simply company policies, but in reality, one of those companies is
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interested in consumption because they live of consumption
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, they are not really interested in what we have, each electronic component in our home consumes energy just like these resistors. Let
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me explain that each component draws a different current, in this case due to its current, but we are going to see some circuits called
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parallel and mixed that each component consumes current the sum of the currents is the total current of
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our home in this case it would be the total current of the circuit
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the energy meters or those that are in charge
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outside our home of
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count how much electrical or energy or power consumption we have in our home. What they are not interested in is that we have.
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They are interested in the total resistance of our home. How much of that total resistance is consumed in electrical energy.
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Here it does the same.
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I have a source to The source is not interested in knowing
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how many resistors I have. I can have 100 resistors. Here we are interested. It is she who is interested in this. The source, seen from here,
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how much is the total resistance.
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In this case, it is a very simple example. The total resistance that looks at the source is
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30 k
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, that is, that is what the source sees.
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It is a resistance zone of
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30 kilos.
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That is what the source sees.
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Having already got my total resistance, the next point is to find this one and
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in any part of the circuit
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I already have a simplification that it is a single resistor
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the second step would be to find the total current
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I am going to delete the board to be able to do the entire exercise from this corner
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Here as we can see I did the sum 10 beds 10 beds of 30 k sca a clarification
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everything that you add it has to be in the same units you cannot add obvious
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known ones because it will not give the same result in this case for simplicity everyone was 10 k
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sorry everything was here so I increased them so the result was 10 kilos
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As already I drew it
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It is 30 kilos here I can calculate seconds of the little triangle we have
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and for the then we want to solve and then it is b over r is equal to iu
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that is, the voltage is equal
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to the voltage of the source 12 volts divided by the total resistance
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in this case in this example I am going to use
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all of them to use it
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like this
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volts over years what they give me is amperes so I do the division 12 over 30,000
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performing that division gives us a value of
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0 point
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4 amperes
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According to the table of prefixes multiplying times 1000 or running 30 it would be 12
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30
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4000
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Amperes by nomenclature the first lower case letter is used and the second
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capital letter should always be used this way to carry out an order in the calculations
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with this we have determined the total current that is, the current consumed by this circuit in series is 0.4
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amperes
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now let's look at how many volts each resistor consumes
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in a practical way and without doing calculations we said that if the source
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Sorry about sources of 15 here there is an error what it has done to 12
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It is 15 divided by 30 thousand
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From 0.05 amperes I Excuse me, I had taken 12 volts and I would have been around 15,
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now we are going to actually calculate how much one, two and three is.
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Theoretically, we had said that it is more or less five volts
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because the voltage is divided according to the law that we had for a while, which said that they bounce in the source is equal to the sum of
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the internal voltages,
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another clarification,
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none of the internal voltages can ever exceed the voltage of the source because it does not make sense,
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that is to say, I have a voltage of 15 and an internal voltage of 30, no element is supplying its power to me. voltage
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is being divided therefore you cannot give higher
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as we calculate
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b1
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b1 is the voltage that falls here in the first resistance
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according to Ohm's law is equal to and because
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the total current is the same here here and here
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therefore that current which I just calculated it, it is the one that I am going to use in my calculations, that is, it would be
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0.00 5 x 10 thousand
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12.
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That is equal to
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5.
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Here they are multiplying omnium
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Amperes by shoulders,
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the result will be volts,
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since the resistances are equal, it will always give us
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5 volts. in b1 b2 and b3
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with this we have just verified in a practical way that
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the calculation is indeed the same as what we have said in the initial part
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if we use different resistances obviously the voltage passed is different
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the other conclusion that we can draw is the higher the resistance the higher the voltage The lower the resistance,
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the lower the voltage. In this case, since they are the same, we could not
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observe that effect
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, but now on a practical level I am going to do it with different resistances than the one they propose here and you will notice.
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This phenomenon follows the lower the resistance,
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the higher the current and it is logical if there is something that means less, then more happens and the higher the resistance, the lower the current.
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Now we will see in a practical way how the law works. Today
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we are going to look at how current is measured and we are going to look at how. It is measured in resistance and voltage in a
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series circuit like the one we propose on the board.
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In this first part we are going to look at how the proto board works before making the connection to it. A protoboard
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is practically our test board, it is the one on which we carry out all our measurements
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we make our assemblies a test is nothing more than a sheet
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that is full of online
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conversations
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so
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from the middle down there is no this connection
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and at the top we have
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sheets that go from start to finish which are usually two and There are students who use it as more and as less.
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Here I have one that is
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assembled from the back and we can see that it is the tics.
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So if you connect a resistor, for example, in this same column here, that is a short, that is not It must be done
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here we have a look at the connection completely of
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our breadboard on the back and we have a sheet that crosses from right to left
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from right to left
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and they are disconnected one because it is positive and negative but you as a user define that it does not bring us
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In this case, for example, this one has colors, they say red and blue, so
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let's respect that polarity and always use red as positive and black as negative,
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which should be done and what can't be done. In these protocols, for example, I have a resistor,
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the correct thing is use the resistors like this towards there
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yes or
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use it downwards
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like this but never use the
00:24:24
In the same column
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that is a short because remember that underneath some can then it is as if I
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took a bare wire and joined like this
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then how old am I zero because a cable has zero thousand and I am shorting the circuit so that should not be done
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this is the correct way when we use integrated ones
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let's not use them all up here
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that is a short because the pin here with the caste pin and not short In the same column,
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the ideal is that the integrated ones always go in the middle, the half separates from the upper part and the lower part
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always makes that separation,
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as we have a breadboard that has
00:25:09
negative to the river and positive, so what I have done is unite
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more with the plus and the minus with the minus through two cables in one of its corners
00:25:19
there is a breadboard that here in the middle has no continuity
00:25:23
continuity means that it asks for the current to pass or that is,
00:25:27
there is no way to be a little bridge from here here from here here for example is the protocol here look at it
00:25:35
w2 in this we have to make a little bridge because there are people who make the connection and forget to make the bridges and it does not
00:25:42
transport the current from this side to this side because it is w isolates it
00:25:47
and has based In this criterion and with the experience that little by little we are going to develop, now we can
00:25:53
know how it is going to be connected.
00:25:55
Remember these are columns,
00:25:58
they are pure columns, yes, and these are files. In real conveyors, they work at the end of
00:26:04
columns, the only ones that work in rows. They are the top part
00:26:08
so we are going to choose
00:26:10
Three resistors here I have a black coffee
00:26:15
tomato resistor which in a few words is 10 k it does not matter where you place it
00:26:20
there are people who say I have to place it at the beginning I have to place it here no it does not matter
00:26:24
you do not know about In the rest of the photo, when I am using it
00:26:28
I can place it here and here here here here here there is no problem.
00:26:33
We place it there
00:26:35
here I have another resistance of
00:26:38
1200 so
00:26:40
the idea is that this fence
00:26:42
is interconnected with the next one, the next one, that is, They are joined together, it is as if in the air I welded them
00:26:47
or joined them, then the protagonist that is what makes them join together
00:26:52
using the sheet that is at the bottom, there is no problem if you place it here, for example, it will be a zoom.
00:27:05
There is no problem. problem if you place him here in this little space or in this little space in this good is what
00:27:11
The important thing is that they are in the same column. In this case, I am going to place it down
00:27:16
here.
00:27:24
Ready and I am going to place my last resistance.
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From another hole, for example, up here, and it does not have to be in the same row over here. I cannot use it down here.
00:27:38
There is no problem there I already have three resistors
00:27:43
interconnected with each other this is the simplest way how it can be done and today I have 10 k 1200
00:27:51
and
00:27:53
6000 6.5 here we are going to check if those values are real then we take our multimeter
00:28:01
ready here we have our multimeter it we are going to place the first one is black coffee tomato according to the color code it
00:28:09
is equivalent to 10,000 òmnium or 10 kilos
00:28:12
so we placed it on the 20 k scale black tip in the black red in
00:28:18
sorry black tip in the com and red says b so we take We can measure these resistances
00:28:23
outside or in this case I am going to measure them here in a series circuit, there is no problem.
00:28:30
As we can look at the resistance, it is measuring
00:28:33
9.83 kilo omnium,
00:28:36
approximately 10 k. The second one is brown, red, red, gold, that is,
00:28:42
1200 omnium,
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we place it here
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and Look at
00:28:51
1.19 here or approximately 1.2 and we are going to measure the other one which is
00:28:58
green blue red
00:29:01
5.6 here we put
00:29:06
5.52
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kilovolts here
00:29:08
so now we are going to do the
00:29:11
theoretical calculation to see how much the value it should give us
00:29:16
then we have For example, a resistance of 10 kilos
00:29:21
plus a residence of
00:29:23
1.2 kilos
00:29:25
plus a resistance of
00:29:27
5.6 kilos, men, we are going to do the operation, we pay for our multimeter,
00:29:33
that gives us a resistance of
00:29:37
16.8 kilos, obviously
00:29:41
everything adds up, so therefore the result is here where It says that it is
00:29:46
16.8, let's check if this result is actually true,
00:29:52
then we turn on our multimeter.
00:29:58
It says that it gives 16, which means that on the 20 k scale I can perfectly measure it.
00:30:05
Theoretically, they give me
00:30:07
16.8, practically, it gives me
00:30:10
16.5.
00:30:11
This, this change, this value that differs is because The tolerance of each of the resistors,
00:30:18
if each resistor has a tolerance, is added with the other tolerance or against the other difference of the other resistors
00:30:24
and therefore the final result will never be the same.
00:30:28
One way to check if it is the same would be
00:30:31
to write down all of them. the practical values add the practical values and there it will be equal to what our multimeter shows.
00:30:40
Now let's look at how we can power our circuit and check
00:30:46
the voltage and current rating of each of these circuits.
00:30:50
So far we have done what is the part theory of
00:30:54
checking total resistance
00:30:57
in a next video, so as not to lengthen this one, we are going to look at how to measure the voltages and currents of this circuit.
00:31:05
See you in a next tutorial.