1 00:00:00,690 --> 00:00:19,789 The polars are between electric and electronic circuit because you can have these types of parts in electric circuit and also in electronic. 2 00:00:19,789 --> 00:00:29,289 But from my point of view they are more important in electronic than in electric circuit. 3 00:00:29,289 --> 00:00:43,289 In any case, we are going to study this dipole and then its application to different things in different moments. 4 00:00:43,289 --> 00:01:07,430 We will start with some basic contents and then we are going to describe the importance of resistance, resistances, condensators and coils. 5 00:01:07,430 --> 00:01:26,329 So let's start with the introduction, which is just only several contexts, important, several and very basic contexts, which is electric current, for example, is the movement of electrical charge, of electrical loads. 6 00:01:26,329 --> 00:01:39,329 But it is also the church, the electricity is a characteristic of the matter, it's inside the matter, if you have matter you have electricity. 7 00:01:39,329 --> 00:01:58,329 So, it's a very natural nature phenomena that in our society can be used for several things. 8 00:01:58,329 --> 00:02:19,729 Nowadays we usually use electronic devices, so electricity is very important in our daily lives, and some basic knowledge of it and how it works I think is important also. 9 00:02:19,729 --> 00:02:33,729 So, to improve the movement of churches we need something material support, material support which is electrical circuits. 10 00:02:33,729 --> 00:02:45,729 They usually have different conductors, also some batteries and obviously some elements of control, 11 00:02:45,729 --> 00:02:59,530 as we have already a study before but circuits you can have a three important 12 00:02:59,530 --> 00:03:05,729 settlements which are firstly resistance resistance is the opposition of the 13 00:03:05,729 --> 00:03:15,430 things to the movement of charge inside well but we can also use a specific 14 00:03:15,430 --> 00:03:24,129 resistors that can help us to control the value of the voltage in for 15 00:03:24,129 --> 00:03:34,250 example in another part of our circuit or in a relay or something 16 00:03:34,250 --> 00:03:47,689 similar. And as we have already said, the resistors can be variable, can have a variable 17 00:03:48,969 --> 00:03:56,330 with different physical phenomena. For example, we have already studied in second of ESSO 18 00:03:56,330 --> 00:04:06,830 the light resistance dependence which is a resistance that increase when you 19 00:04:06,830 --> 00:04:20,449 have a pure light if you have a low intensity of light and we have also for 20 00:04:20,449 --> 00:04:27,449 example potentiometer or another variable resistors but we also have a 21 00:04:27,449 --> 00:04:37,370 fixed six value for and to know this value we usually use the color code for 22 00:04:37,370 --> 00:04:45,629 resistors the color code for resistor consists in three in four lines one of 23 00:04:45,629 --> 00:05:01,949 these lines just only can have very few colors, golden, silver, white, so you can know it 24 00:05:01,949 --> 00:05:16,990 is the fourth or the one strip. The other three correspond to the nominal value of the resistor. 25 00:05:18,189 --> 00:05:28,990 The first is a digit and the second also and the third is a number of O's, a number of zeros that 26 00:05:28,990 --> 00:05:39,449 you must add it each is a strip each line has different color so a black for 27 00:05:39,449 --> 00:05:51,730 example correspond a to all to the to the numeric value of a brown one red two 28 00:05:51,730 --> 00:06:08,709 orange 3 yellow 4 green 5 blue 6 violet 7 gray 8 and white 9 so you can know the value of the 29 00:06:08,709 --> 00:06:21,370 resistor taking into consideration the colors of the digit of this strip the position and with 30 00:06:21,370 --> 00:06:30,730 If you use this, you can know the nominal value of the resistors. 31 00:06:30,730 --> 00:06:39,110 The fourth line just only can give you the tolerance, it depends if you have golden one 32 00:06:39,110 --> 00:06:45,490 is 5%, if you have silver one is 10%. 33 00:06:45,490 --> 00:06:50,990 will do some exercise of this because it's the only way that you can 34 00:06:50,990 --> 00:07:00,470 understand it properly. The second dipole that we are going to study is 35 00:07:00,470 --> 00:07:09,110 condenser. Well a condenser can be defined, you have a different kind 36 00:07:09,110 --> 00:07:20,870 types of condenser but the most the typical one is formed by metal places 37 00:07:20,870 --> 00:07:28,730 between which there is a dielectric when a condenser accumulates current there is 38 00:07:28,730 --> 00:07:37,569 a time to be in the same also called relaxation time for both loading and 39 00:07:37,569 --> 00:07:47,430 downloading you have different times so what happened is that the condenser is 40 00:07:47,430 --> 00:07:59,110 like a glass and the current like a water you need to to have a glass plenty 41 00:07:59,110 --> 00:08:12,730 of water if you want to close your circuit. So they usually use as tempers because the time 42 00:08:12,730 --> 00:08:27,050 that you need to fill the condenser is the product of resistors and the capacity of the condenser. 43 00:08:27,050 --> 00:08:40,669 the capacity we also do some exercise and well capacity of condenser the unit for capacity is 44 00:08:40,669 --> 00:08:52,610 faraday but faraday is so so big to be so we usually use nano or micro faraday which are 45 00:08:52,610 --> 00:09:07,070 submiter poles of Faraday. Well, the important element is coil. As we have already known, 46 00:09:07,070 --> 00:09:19,370 if you have current, if you have charge which are moving, you have a magnetic field. So the 47 00:09:19,370 --> 00:09:40,929 The good news is that the magnetic fields can interact in one with each other, and this is usually used, for example, in electric machines, in motors, or in alternators, for example, in alternators, in generators. 48 00:09:40,929 --> 00:09:54,529 because it is usually used to generate electricity, because if you have a variable flux of this 49 00:09:54,529 --> 00:10:02,169 magnetic field you can generate an electric field, an electric electricity. 50 00:10:02,169 --> 00:10:17,769 So this phenomena, which has a magnetic flux changing in the time, is usually called Faraday 51 00:10:17,769 --> 00:10:30,250 length loss and is in so many ways is more or less the same as you have for 52 00:10:30,250 --> 00:10:41,210 the condenser so you can also use coil as tempers but they you 53 00:10:41,210 --> 00:10:52,970 You need very strange values to have the same effects, so in practice we don't use it. 54 00:10:52,970 --> 00:11:01,210 In any case, it's important because they have other uses, such as electrical machines, motors, 55 00:11:01,210 --> 00:11:09,549 alternators, dynamo, so on, that we have already studied in psychoanalysis, and we can also 56 00:11:09,549 --> 00:11:14,519 use in other ways. 57 00:11:14,519 --> 00:11:25,399 That is all for today and I invite you to do the exercise because to clarify other contents 58 00:11:25,399 --> 00:11:27,759 is need to do more practice.