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## Resistors and registers

Resistance means being able to interrupt an activity. In the case of electricity, radiation means electromagnetism - that is, obstructing the flow of electrons. Therefore, the religion of the conductor is the obstruction of the conduction of electrons or ions through the conductor. All substances have some redness. Even the kinship like copper has some redness. But the real thing is - the conductivity is low, and the non-conductive radius is high.

We know that the electric current is a positive and negative ion and the electric current is the flow of electrons in a certain direction. Again, the number of free electrons is different. So if the same amount of voltage is applied, then the amount of current flow will be different for different substances. The greater the current through which the current flows, the lower the radius of that substance. And the lower the current through which the current flows, the greater the radius of that substance. Therefore, by saying the resistance, we will understand that the total current generated by the conduction constant is as much as the resistance of the electric current.

The device that is used to prevent the flow of electrons in an electronic device is called a resistor. However, it has been observed that technicians use the term resistances more often than the words of the registrar - a fact that the students always keep in mind. However, in the book, we will use the register or resistor for the convenience of the book, and two different cases of resistance or radiation.

* Laws of Resistance dependent on what matters.

The magnitude of a conductor depends on a few factors. This is called the Radha formula or 'Law of, resistance'.

(a) On material - the radius of different substances is different. That is, radar changes for different materials.

(b) If the length of a conductor increases over the length, its radius also increases. That is, the length | If current, the current flow is reduced.

(c) On the cross-section - As the width of a conductor increases, that is, the radius decreases when there is more soil. As the width increases, the current flows up. Because of this, the radius of the META wire is low and low, | The wires are high.

(d) As the temperature of a conductor increases with temperature, its radius also increases. As the temperature of the conductor increases, the velocity of the free electron in the center of the conductor also increases. Due to this extremely rapid rate of electrons, the amount of collision between them also increases. And as the conflict escalates, Radha also grows.

Again, there are exceptions. In the case of carbon and some other substances, it is observed that as the temperature rises, their radiation decreases.

From the above, we learned that the resistance of a particular substance at a certain temperature depends on its length and width.

We can find the upper (b) and (c) numbers in the figure -

R = p 1 / A [while both 1 and A are variable]

Now 1 is the length, A is the quotient and p is the constant. p is called relative radius. It depends on the material of the conductor If 1 = 1 cm. And A = 1 Sq. cm. If either, then p = R would be. That is, the linearity of an element is the radius of a single cube of that element. 1 cm here. Tall, 1 cm. A cube with a width and height of 1 cm will be called a centimeter cube whose volume is 1 c. c. .

Therefore, at a certain temperature (68 ° F), the radius of a substance having a single length and a single area is called the relative radius of that substance. The practical unit of radix is ​​ohm - centimeter (ohm - cm).

Therefore, the radius (p) = RA / 1 ohms - c. Mr. .

* Effect of heat on radius.

Above we have done a little introduction on the effect of heat on radhe, here we will explain in more detail.

(i) As the temperature rises, its radiance increases with respect to pure metal.

(ii) In the case of alloy, the temperature increases with a slight increase in the alloy. The hybrids used in electric work have almost the same radius at all types of temperatures.

(iii) In the case of electrolytes or insulators, such as paper, rubber, mica and bacelite, and partial conduction of carbon, their temperature decreases as the temperature increases.

Radhe's practical unit is' ohm. M. Who S. In the process, Radh's unit is Ohm. Ohm - the symbol is '0'. If the magnitude of a vent on the side of a conductor - the potential difference), if the electric current through it is an ampere, then the radius of that conductor will be called an ohm. To make it a bit simpler, if a voltage is applied to a vent in a conductor, the amount of radius propagation is called an ohm to limit the current flowing in an ampere. This is Radhe's single.

Well, 1 ohm = 1 vol

And both of these terminals are used for soldering to connect to the socket. The wrap on the foam is covered with heat-resistant cement or ceramic. The value of this resistor varies from 1K ohms to 100K ohms. The wattage is 5 watts to 200 watts. According to the structure, the wire under resistor is divided into three parts. Namely - (i) Fixed Wire Wand Registers, (ii) Adjustable Wire Wide Registers, Figures 9 - 1 and (iii) Tape, Wire Wide Registers. The fixture wire is just two connection points to the resistor (Figure - 9 - 2 - A). Its value is specified when creating it. Adjustable, two terminal points on the edge for connection to the wire wand registers. In addition, there are two additional points in the middle (Figure - 9 - 2 - B). The points in the middle are two movable, that is, they can be removed. So the value of the registers can be lowered according to the projection. Therefore, the middle points in the proximal vale have to be adjusted and fixed. This type of resistor is also called 'semi variable register'. Tapered Wire - In the case of a wide register, the terminal terminal points are two In addition to Figure - 9 - 2, there are multiple tappings of different valor in the middle .  Tappings like its terminal point dot are also fixed .  Different tapping according to the proximal val

Is used. | (c) Metal film resistor - A thin layer of metal film is deposited on an insulating form to create this resistor. The terminal wires are attached to the saddle with heavy pressure on the two metal caps. Then a helical notch is made on the metal film and finally all the resistors are submerged in a neutral paste. Here is a picture with a few metal - show portrait of the film register Image - - 3 is (Figure - 9 - 3). (d) The structure of the carbon - film resistor - carbon - film resistor is the same as the metal - film resistor. Here is the metal (ceramic tube) on the insulating form - just carbon instead of film - a thin lining of the film. Is used.

* Variable register

Variable resistors are commonly referred to as 'potentiometers' or 'pots' or controls. It is used in a socket area where the value of the resistance (radhe) in the passage is required to be changed. Either. Such as the use of volume control on the radio, tape recorder or TV. To create a variable register, a layer of carbon (film) is deposited on a plastic base and this layer acts as a radiator. Two layers are added to the two ends of this layer.

The wiping contact point (which corresponds to the middle leg of Fig. 9 - 4), travels from one end of the level to the other, and as a result, the radius of the socket is less. This point in the middle is also called a slider. At any given moment, any valor drawn radius is found at the patensiometer to its highest value. Here is a diagram showing the portrait of a variable register (Figure - 9 - 4). As shown in the figure, points A and C are two sta marginal leg and B point is beams wiping contact point. E Shafter Termini | Comes, with B points attached and E shaft - ~ - rated; The enclosure B travels from one end to the other. Here is an inside diagram showing the inner structure of the patten sheometer (Figure - 9 - 5). Patensiometer when viewing the image of the structure. Understanding how it works will be of benefit. The variable is divided into groups according to the rate of change in the value of the value of the resistor. Namely - log, type and lin type. Varyab. Slicer A and C point team variables in log type (logarithm / log) - the value of this range changes to logarithm, rate. The radius value of such a resistor gradually increases from one head to the other. When looking at the image it is easy to understand this. This type of variable register is usually volume control

And bus, (Bass} used as control. 1 T 20 0 30 3 2 50 ft 80 [ads00. Lege. B0 La৩ T - 3: 00 = | LOG Log. LEAR Figure - 9 - 6 Figure - 9 - 7.

* The linear type of linear type (linear / lin) changes in the proportional rate directly. Each part of this type of register is equal in value. Looking at the image will facilitate understanding (Figure - 9. This type of variable register is usually controlled by television set, contrast control, brightness control, vertical hand, horizontal hold).

Etc. and used as tone control in stereo tape - recorder. There is another type of variable register. That is the warrand type. It uses a wired layer instead of a carbon film layer. The power of the potentiometer depends on the carbon - film layer or the warehouse level. Wired type patensiometer is commonly used in power supply. Again, more than 3 wards of patenciometers are of warwind type. But usually carbon - film potentiometers are used more often. a 08 | Figure - 9 - 8 Figure - 9 - 9 The carbon film potentiometer is divided into three parts according to the composition variation. Namely - (i) Rattery ৯৯৯ Patensiometer (Figure - 9 - 4 / P73); (ii) Sliding type patensiometer (Figure - 9 - 8) and (iii pis | type potentiometer)

Instead of turning them like a potentiometer, the whale's radius is lowered to make them wider. The pre-set is used to adjust the value of the radius in the adjacent value. They have no shaft. They have to be adjusted. - With the help of the driver. Here is a diagram showing the symbol of the fixed resistor (Figure - ~ - 9 - 10 - A), the variable register or parenthesometer (Figure - 9 - 10 - B) and the tapped resistor (Fig - 9 - 10 - C). These symbols are commonly used in the circuit diagram to indicate their presence. Ohm with another image. The emblem is shown (Figure - 9-11).

* How to calculate the value of the register from the color code.

It usually has good, non-standard values ​​written on it to make the size of the wire register. But the carbon register or the metal film register or the carbon -

It is not possible for them to be written in the form of a film register, so that they can be written on their val. So they have to take the help of color to know, Val. This method of determining the value of a color, ie color, is called the color stroke. This color code is the international color code. The color code uses 9 passenger colors and each of these 9 colors has different numbers assigned to it. The first of the registers is usually a brown or some other light color. Of this plague. Each of the above registers has a ring or badge of three consecutive colors - slightly away. The value of the resistor is calculated using these three colors (A, B, C, respectively). One of these three rings. One more ring or other ring of silver on the other side of the register. The bed is provided. This is the fourth color of the resistor {D), and it is usually used to determine the tolerance of the resistor. Often times, the fourth color is not given to the register. That is, the color of the coating of resistab is used as the fourth color. In that case, the fourth color is called 'no color' or 'no color'.

We learned that the ring is used to determine the value of the register. But if you do not know the language of the color of the coat, the colors of the register will remain the same color to us, it does not make any sense. So this time we will learn how to calculate the value of the register, and for this we have a 2nd and 3rd position. Also Figure - 9-12. Get help with images (Figure - 9.12). Generally, in most cases the value of the register is determined by this method. In this method, it is always necessary to start counting the band in the opposite direction of the fourth color - the color of the tolerance. So the first color on the opposite side of the fourth color - the first band or ring (A). First color - The next color is the second band or ring

(B) And the second color - the next color - is the third band or ring C. | This time, the first (A) and second (B) bands of the two bands sit side by side, respectively, that number is the third band. The result obtained by multiplying the specified number by (C) is the value, or value, of the register. The specified number of colors for the fourth band (D) is known as the tolerance of the register. Tolerance is calculated. As a percentage (%). But what does tolerance mean? When the register manufacturer creates this national register, they cannot maintain the correct value of the register. The value of the register register is always less than or equal to the specified value. Either. Tolerance is the least of these values. The polarity corresponding to the regressor uses the fourth band (D) on the register to indicate how much tolerance is in a register. For D-bands, sasanali and silver colors are used or no color is used, ie the color of the resistor is used as a color. Of course

Other colors are also used if needed. Sinhalese color is + 59% forehead value + 10% and if there is no color then its value is 20%. Let's say the first three colors - from 1002, there is no regression. If the fourth color of this resistor is sinhali, then the correct value of the resistor will be ০sorom. 10542 - Any quality within. If the fourth color is silver, the exact value of the register will be 900 to 11oo. Any quality. And if the fourth color has no color in place, then the correct value of the register will be 0o me _ 1202. The value of the register is permissible. So when designing a circuit, the circuit is designed keeping in mind the tolerance of this register. However, as low as possible the tolerance register can be used. But if at any time it is seen why the value of the register exceeds the tolerance level, then the resistor should not be used.

• The color code chart of the register, which is the identity of the different colors and their numbers in the register.

The first band or ring | Second Bad or Ring | Third band or ring The first number of the third band or ring | While the second number is | That is, calculate the sum | That is, tolerance. (Color) =। | =. 10. ° 20% 81% ° 2% ° 3% ০ M ০ M - - 100 1000 or, 1K 1000, 0 or, 10K 1000, 00 or 100K 1000, 000 or, 1M 25% ০ ০ ০ * 6% ) Brown (red). Orange is Yellow, Green is Blue. Violet is gray and white is golden. Silver (no silver) (No color) ০ 2 | । | ০ ° 12: 5% ° 30% ° 10% °

5% ° 10% ° 20% 01 or, 1 0: 01 or by showing some color code, below are some examples of how to calculate the value of a register. The first band (A) | Second band (B) Third band (C) The value of the resistor is brown = 1 black = 0. Sinali = 01 le | Brown = 1 banana = 0 banana = 1 109 orange = 3 orange = 3 brown = 10. 3300 red = 2 red = 2 red = 100. 2, 2002 = 2: 2K green = 5 blue = 6. Orange = 1000 56, 0002 = 56K yellow = 4 violet = 7 yellow = 10, 000 470, 0002 = 470K brown = 1 black = 0 green = 100, 000 1000, 0002 = 1M. Below is an easy way to quickly diagnose using the color = 3 in blue = 1000 in blue = 1000, 000 10, 000, 0000 = 10M in four colors - the value of the associated resistor. (i) The third color of all registers with value from 0: 19 to 0 * 999 will always be silver. (ii) The third color of all registers with values ​​from 10 to 90 will always be Sainali.

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