Fisika

Understanding CAPACITORS

Electronics components this time we will discuss is kapasitor.Selain capacitor's name was condensator.Komponen like resistors are also included in the group of passive components, the type of components that work without the need for bias current.
The types of capacitors are various, such as below.

* According to the Polarity
- Capacitors Polar
Polarity (+) and (-).
Polarity in the installation must be considered and should not be installed upside down. In a sign bodynya polarity to the polarity mark foot (+) or (-).
- Non Polar Capacitor (Capacitor Bipolar)
This capacitor type can be mounted back and forth.


* According to the Material Pembuatannya
The capacitor is basically two pieces of metal plate (dielectric) separated by a material Isulator. Well, here's the clincher material Isulator capacitor name.
According to the materials of manufacture jenis2 capacitor is:
- Electrolytic Capacitors → isulatornya made from electrolytic
- Capacitors Mika → isulatornya material made from mica
- Capacitors Air → isulatornya material made from the air.
- Paper Capacitors, Tantalum, mylar, etc..

* According to the assessment value is
- Capacitors Fixed / Permanent
Capacity value can not be changed.
- Variable Capacitors sometimes called VC or Varco (variable capacitor)
Capacitors of this type we can change the value to change.

The function of a capacitor is to store the current / voltage. For current DC capacitors serve as Isulator / retaining an electrical current, while AC current function as a conductor / passing an electric current.
In application is used as a filter capacitor / filter, rectifier voltage DC to AC to DC converters, ac wave generator or oscillator etc..

Capacitor value can be seen in the writings found on her body, for example, 10 uF/16 V means that the capacitor value is 10 micro Farad and can operate at maximum voltage of 16 V, if it exceeds 16 V, the capacitor will experience 'break down' aka ko'it :-).
Farad is the unit value of the capacity of the capacitor.
1 uF → 1 micro Farad = 1 x 10 ^ (-6) = 0.000001 Farad Farad
1 nF → 1 nano farad = 1 x 10 ^ (-9) Farad
1 pF pico Farad → 1 = 1 x 10 ^ (-12) Farad

# Code Number In Capacitors
For capacitors rated capacity below 1 uF capacity value normally written in code numbers.
Example:
1. 104 → 10 x 10 ^ 4 (in units of pico Farad) = 100000 pF or 100 nF or 0.1 uF
2. 222 → 22 x 10 to the power 2 (pF) = 2200 pF or 2.2 nF
* How are we rewrite the first two numbers, then we multiply by 10 to the last digit.
3. 4N7 → 4.7 nano farad
4. 2P5 → 05.02 pico Farad

Capacitors are uF value below 1 is generally non-polar type, except for the type of electrolyte.

IniDalam image below schematics capacitor is a capacitor electronics symbols are as under iniYang no sign (+) and (-) is a symbol of the non-polar capacitor while the (+) and (-) is a non-polar capacitor symbol.
CAPACITOR (Condenser)
Capacitors (capacitors) that the electronic circuit is denoted with the letter "C" is a device that can store energy / electric charge in an electric field, by collecting internal imbalance of electric charge. Capacitors discovered by Michael Faraday (1791-1867). Unit called the Farad capacitor (F). One farad = 9 x 1011 cm2, which means the surface area of ​​the strip.
The structure of a capacitor is made of two pieces of metal plates separated by a dielectric material. Dielectric materials are commonly known as air vacuum, ceramics, glass and others. If both ends of the metal plate was given voltage, the positive charges will accumulate on one leg (electrode) metal and at the same time the negative charges accumulated on the other end of the metal. The positive charge can not flow toward the negative pole and the opposite end of the negative charge can not go to the end of the positive pole, being separated by a dielectric material that is non-conductive. Electric charge is stored for no conduction at the ends of the legs. In the wild, these capacitors phenomenon occurs when the accumulation of positive charges and negative in the cloud.

1.1. Capacitance
Capacitance is defined as the ability of a capacitor to hold the charge of electrons. Coulombs in the 18th century calculate that 1 coulomb = 6.25 x 1018 electrons. Then Michael Faraday made postulate that a capacitor will have a capacitance of 1 farad when a voltage of 1 volt can contain as much as 1 coulombs electron charge. With the formula can be written:
Q = C V
Q = the electron charge in C (coulombs)
C = capacitance in F (farad)
V = the voltage in V (volts)
In practice the manufacture of capacitors, capacitance is calculated by knowing the area of ​​the metal plate (A), distance (t) between the two metal plates (dielectric thickness) and constant (k) dielectric materials. With the formula can be written as follows:
C = (8.85 x 10-12) (k A / t)
Here is a sample table constants (k) of some dielectric materials is simplified.

For practical electronic circuits, unit farad is a very large one. Generally capacitors on the market has units: μF, nF and pF.
1 Farad = 1,000,000 μF (micro Farad)
1 μF = 1,000,000 pF (pico Farad)
1 μF = 1.000 nF (nano Farad)
1 nF = 1000 pF (pico Farad)
1 pF = 1.000 μμF (micro-micro-Farad)
1 μF = 10-6 F
1 nF = 10-9 F
1 pF = 10-12 F
Conversion unit for ease of reading is important to know the amount of a capacitor. 0.047μF example can also be read as 47nF, or another example of the same 0.1nF 100pF.
Identified condenser has two legs and two poles is positive and negative and has a liquid electrolyte and usually tubular.

While most of the other types of rated capacity is lower, does not have a positive or negative pole on her feet, mostly in the form of flat round brown, red, green and other such tablets or buttons often called capacitors (capacitor).

2.2 The nature and kind of capacitor
Based on usefulness condenser is divided into:
1. Fixed capacitors (rated capacity can not be changed)
2. Electrolytic Capacitor (Condenser electrolit = Elco)
3. Variable capacitor (rated capacity can be changed)
In a large capacitor, the capacitance value is generally written by the sheer numbers. Complete with a maximum voltage value and polarity. For example, the elco capacitor capacitance was clearly written by 100μF25v which means the capacitor / capacitor has a capacitance of 100 μF value by the maximum allowable working voltage of 25 volts.
Capacitors are small physical size is usually only read 2 (two) or 3 (three) numbers only. If there are only two numbers, unit is pF (pico farads). For example, a capacitor that reads two numbers 47, the capacitor capacitance is 47 pF. If there are 3 digits, the first and second shows the nominal value, while the 3rd digit is the multiplier. Multiplying factor according to the nominal rate, respectively 1 = 10, 2 = 100, 3 = 1000, 4 = 10000, 5 = 100000, and so on.
Example:

For polyester capacitors capacitance value can be known by the color as in the resistor.

Example:

As with other components, there is a large nominal capacitance tolerance. In Table 2.3 are shown the value of tolerance with codes specific numbers or letters. In the table the user can easily determine tolerance capacitors are usually listed accompany nominal capacitor value. For example, if a written 104 X7R, then the capacitance is 100nF with a tolerance of + / -15%. Please also note that once the recommended working temperature is between-55Co to +125 Co.


From the above it can be known that the addition capacitance capacitor characteristics is equally important that the working voltage and operating temperature. The working voltage is the maximum allowable voltage that the capacitor can still work well. For example 10uF25V capacitor, the voltage that can be given should not exceed 25 volts dc. Generally, polar capacitors work on DC voltage and non-polar capacitor works on AC voltage. While working temperature limit is the temperature at which the capacitor can still work optimally. For example, if the written X7R capacitor, the capacitor has a recommended operating temperature between-55Co to +125 Co. Usually these characteristics specifications presented by the manufacturer in the datasheet.
2.3. The series capacitor
The series capacitor in series will result in less total capacitance value. Below is an example of capacitors arranged in series.

In a series of capacitors arranged in series applies the formula:

The series capacitors in parallel will result in the greater capacitance value replacement. Below is an example of capacitors arranged in parallel.

In parallel capacitor circuit applies the formula:

2.4. Function Capacitors
The function uses a capacitor in a circuit:
1. As the coupling between one circuit to another circuit (the PS = Power Supply)
2. As a filter in series PS
3. As the frequency generator circuit antenna
4. To save power the neon lights
5. Eliminating bounce (stepping fire) when installed on a switch
2.5. Type Capacitors
The capacitor consists of several types, depending on the dielectric material. For more simple can be divided into 3 parts, namely electrostatic capacitors, electrolytic and electrochemical.
• Electrostatic Capacitor
Electrostatic capacitors are the capacitors are made with a dielectric material of ceramic, film and mica. Ceramic and mica is a popular material and cheap to make small capacitance capacitors. Quantities available from pF to several μF, usually for a series of applications relating to high frequency. Including the dielectric films are raw materials such as polyester (polyethylene terephthalate, also known as Mylar), polystyrene, Polyprophylene, polycarbonate, metalized paper and more.
Mylar, MSM, MKT are some examples of the trademark name for a capacitor with a dielectric material film. Generally this group of capacitors are non-polar.
• Electrolytic Capacitors
Electrolytic capacitor group consisting of capacitors dielectric materials are metal-oxide layer. Generally capacitor including this group is polar capacitor with the + and - in the body. Why are these capacitors can have a polarity, is due to the manufacturing process uses electrolysis to form the positive pole and the negative pole anode cathode.
It has long been known for some metals such as tantalum, aluminum, magnesium, titanium, niobium, zirconium and zinc (zinc) surface can be oxidized to form metal-oxide layer (oxide film). Oxidation layer is formed through the process of electrolysis, as in the process of gold plating. Metal electrodes immersed in an electrolyte solution (sodium borate) and given a positive voltage (anode) and the solution given electrolit negative voltage (cathode). Oxygen in electrolyte solution apart and oxidize the surface of the metal plate. For example, if you use aluminum, it will form a layer of aluminum oxide (Al2O3) on the surface.

Thus successive metal plate (anode), layer-metal-oxide and the electrolyte (cathode) form a capacitor. In this case the metal-oxide layer as a dielectric. From the formula (2) the unknown capacitance is inversely proportional to the dielectric thickness. Metal-oxide layer is very thin, and thus can be made large enough capacitance capacitors.
Due to economical and practical reasons, it is generally a lot of metal materials used are aluminum and tantalum. Most materials are plentiful and cheap aluminum. To get the surface area, the material is typically rolled aluminum plate radial. So in a way that can be obtained large capacitance capacitors. For example 100uF, 470uF, 4700uF and others, which is also called a capacitor elco.
Electrolyte materials in liquid tantalum capacitors there but there are also solid. Called solid electrolyte, but are not really the solution electrolit its negative electrode, but other materials are manganese-dioxide. Thus this type of capacitors can have a large capacitance, but becoming more slender and petite. In addition, because all the solid, then their work time (lifetime) to be more durable. This type of capacitor has a leakage current is very small so it is understandable why Tantalum capacitors become relatively expensive.
• Electrochemical Capacitors
One other type of capacitors are electrochemical capacitors. Including this type of capacitors and batteries is the battery. In fact, battery and capacitor batteries are very good, because it has a large capacitance and leakage current (leakage current) is very small. This type of capacitor types are also still in development for a large capacitance, but small and light, for applications such electric cars and mobile phones
Capacitors are electronic components that can store electrical charge. The structure of a capacitor is made of two pieces of metal plates separated by a dielectric material. Dielectric materials are commonly known as air vacuum, ceramics, glass and others. If both ends of the metal plate was given voltage, the positive charges will accumulate on one leg (electrode) metal and at the same time the negative charges accumulated on the other end of the metal. The positive charge can not flow toward the negative pole and the opposite end of the negative charge can not go to the end of the positive pole, being separated by a dielectric material that is non-conductive. Electrical charge is "stored" as long as no conduction at the ends of the legs. In the wild, these capacitors phenomenon occurs when the accumulation of positive charges and negative in the cloud
Rectifier circuit with Filter Capacitors
The average rectifier output is DC voltage with ripple (ripple). To change this ripple to a fixed DC voltage, it takes a strainer (filter) using a capacitor as shown in figure 6

Figure 6. The hand with filters C
The process of charging and discharging currents (charging and discharging) the capacitor circuit, relies heavily on the prices of Resistors and Capacitors. Voltage at kapasistor when the charging process is as follows:

while the flow equations for the disposal process is as follows:

where konstantat time decay, commonly known as the time constant t, ie: t = RC
Role Capacitors in Electrical Energy Usage

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Modern life one character is a large consumption of electrical energy. The amount of electrical energy or load that is used is determined by the reactance (R), inductance (L) and capasitansi (C). The amount of electrical energy consumption was due to numerous and diverse equipment (load) of electricity used. While commonly used electrical load is inductive and capacitive. Where the load is inductive (positive) reactive power required as the rectifier transformers, induction motors (AC) and fluorescent lamp, while the capacitive load (negative) issue of reactive power. Reactive power is power that is useless and so can not be converted into energy but it is necessary for the transmission of electrical energy to the load. So that led to a waste of electrical energy is the amount of equipment that is inductive. Means of using electrical energy turns customers not only burdened by the active power (kW), but also the reactive power (KVAR). The sum of the two forces that will produce real power is the power supplied by PLN. If a value is magnified power that is usually done by industry customers the power loss becomes big is the active power (kW) and voltages up to the consumer is reduced. Thus, the industry's production will decline this certainly should not be going for it from the power supply plus PLN should mean increased costs. Because the power is P = VI, then by increasing the amount of power means a decline in prices and the rising prices of V I. Thus, active power, reactive power and apparent power is an entity that would be described as a right-angled triangle in Figure 1.
From Figure 1 it is obtained that the ratio of active power (kW) to apparent power (kVA) can be defined as the power factor (pf) or cos r.
cos r = pf = P (kW) / S (kVA) ........ (1) P (kW) = S (kVA). cos r ................ (2)
As we know that the price cos r is from 0 s / d 1. Means the best conditions, namely when the price P (kW) maximum [P (kW) = S (kVA)] or the price cos r = 1 and is also called the cos r the best. But in reality the price cos r determined by PLN as the party of power supply is at 0.8. So for the price cos r <0.8 means pf say ugly. If the customer pf bad (low) then the capacity of active power (kW) that can be used customer will be reduced. Capacity will continue to decline along with the decline pf electrical system customers. By decreasing pf it will display some of the problems as follows: a. Enlarged kWH power usage due to losses. b. The growing use of electrical power kVAR. c. Power quality to be low because of the voltage drop. Theoretically the system with a low pf course will cause the current required from a major supplier. This will lead to a total loss of power (reactive power) and voltage drop becomes large. Thus, the penalty shall be paid sebabpemakaian increased reactive power to be great. Excess fines or fees imposed if the amount of reactive power usage in a month tercata kVARH which is higher than 0.62 kWH amount in question so that pf an average of less than 0.85. While the excessive use of kVARH in dollars using the following formula: [B - 0.62 (A1 + A2)] Hk Where: B = k VARH use kWH usage WPB A1 = A2 = kWH usage LWBP Hk = price overuse kVARH To increase prices r cos (pf) is low easy thing to do is to reduce the angle so that it becomes r1 r means r> r1. Moderate to minimize the angle r is the possible is to reduce component reactive power (KVAR). Means that there are components of reactive power is inductive to be reduced and that the reduction can be done by adding a source of reactive power in the form of capacitor.
The process of reduction is possible because both the load (inductor and capacitor) opposite direction as a result of reactive power to be small. When reactive power to active power remains small while the price of a big result pf apparent power (kVA) to be small so that the electricity bill is reduced. Meanwhile, another advantage with decreasing reactive power is:
• Reduced power losses in the system.
• An increase in voltage as the power increases.
Capacitors Work Process
Capacitors to be used to enlarge pf in parallel with the load circuit. When the series was rated voltage the electrons will flow into the capacitor. At the time of the capacitor filled with the electron charge voltage will change. Then out of the electrons will flow into the capacitor and the circuit thus the need saaat that generate reactive power capacitors. When the voltage is changed it back to normal (fixed), the capacitor will keep returning electrons. By the time capacitor emit electrons (Ic) means the same treaktif power supply capacitors to the load. Faucets load is inductive (+) while the reactive power is the capacitor (-) as a result of reactive power tends to be small.
Power loss before replacing capacitors:
Active power losses ............. = I2 R Watt (5)
Reactive power loss = I2 x VAR ......... (6)
Power loss after capacitor installed:
Active power loss = (I2 - IC2) R Watt ... (7)
Reactive power loss = (I2 - IC2) x VAR (8)
Installation of Capacitors
Capacitors to be used to minimize or correct placement pf there are two ways:
1. Centralized capacitors placed on:
a. Primary and secondary side of the transformer
b. At the central bus controller
2. How limited capacitors placed
a. Small Feeder
b. At the branch circuit
c. Jump on the load
Treatment Capacitors
Capacitors are used to improve the pf so durable would have to be treated on a regular basis. In the nursing care must be taken in damp areas that are not protected from dust and dirt. Before conducting the examination confirm that the capacitor is not connected anymore to the source. Then, because it still contains the capacitor charge means that there is no current / voltage, the capacitor is shorted should be linked so that the load is lost. The type of inspection to be performed include:
• Examination of leakage
• Checking cables and buffer capacitor
• Examination of insulator