Types Of Capacitors And Their Applications

Types Of Capacitors And Their Applications Introduction:  Capacitor is one of mostly used component in electronic circuit design. It plays an important role in many of the embedded applications. It is available at different ratings. It consists of two metal plates separated by a non conducting substance, or dielectric. A capacitor stores an electrical charge between the two plates, The unit of capacitance is Farads (F). It is often storage depots for analog signals and digital data

Types Of Capacitors And Their Applications Common Types of Capacitors 1. Film Capacitors 2. Ceramic Capacitors 3. Electrolytic Capacitors 4. Variable Capacitors

Types Of Capacitors And Their Applications Film Capacitors  Film Capacitors comprising of a generally expansive group of capacitors with the distinction being in their dielectric properties.  Film Capacitors are available in almost any value and voltages as high as 1500 volts.  They come in any tolerance from 10% to 0.01%.  There are two types of film capacitors.  They are radial lead type and axial lead type.

Types Of Capacitors And Their Applications Film Capacitors  The electrodes of film capacitors may be metalized aluminium or zinc.  It applied on one or both sides of the plastic film.

Types Of Capacitors And Their Applications Film Capacitors  It resulting in metalized film capacitors called film capacitors.  Film capacitors additionally arrive in a combination of shapes and case styles.  Film Capacitors are sometimes called plastic capacitors.  It use polystyrene, polycarbonate or Teflon as their dielectrics.  These film sorts need a much thicker dielectric film to lessen the danger of tears.

Types Of Capacitors And Their Applications Film Capacitors  It is more suited to lower capacitance values and bigger case sizes.  The film capacitors are physically larger and more expensive, they are not polarized.  It can be used in AC voltage applications, and they have much more stable electrical parameters.  Dependence of capacitance and dissipation factor.  Film Capacitors can be applied in frequency stable Class 1 applications, replacing Class 1 ceramic capacitors.

Types Of Capacitors And Their Applications Ceramic Capacitors  Ceramic capacitors are used in high frequency circuits such as audio to RF  Ceramic Capacitors are the best choice for high frequency compensation in audio circuits.  These capacitors are also called as disc capacitors.  Ceramic capacitors are made by coating two sides of a small porcelain or ceramic disc with silver and are then stacked together to make a capacitor.

Types Of Capacitors And Their Applications Ceramic Capacitors  One can make both low capacitance and high capacitance in ceramic capacitors.

Types Of Capacitors And Their Applications Ceramic Capacitors  It can be made by changing the thickness of the ceramic disc used.  They come in values from a few Pico farads to 1 microfarad.  The voltage range is from a few volts up to many thousands of volts.  Ceramics are inexpensive to manufacture and they come with several dielectric types.

Types Of Capacitors And Their Applications Electrolytic Capacitors  It is most prevalently used capacitors which have a wide tolerance capacity.  Electrolytic capacitors are available with working voltages up to about 500V.  There are two types of electrolytic capacitor, tantalum and aluminium in common.  Tantalums capacitors have ordinarily better exhibition, higher value.

Types Of Capacitors And Their Applications Electrolytic Capacitors  The dielectric properties of tantalum oxide is much superior to those of aluminium oxide.

Types Of Capacitors And Their Applications Electrolytic Capacitors  It has an easier leakage current and better capacitance strength which makes them suitable for obstructing, decoupling, filtering applications.  The thickness of the aluminium oxide film and heightened breakdown voltage gives the capacitors exceptionally elevated capacitance values for their size.  In a capacitor the foil plates are anodized by a dc current thus setting of the extremity of plat material and confirming polarity of its side.

Types Of Capacitors And Their Applications Variable Capacitors

Types Of Capacitors And Their Applications Variable Capacitors  A Variable Capacitor is one whose capacitance may be intentionally and repeatedly changed mechanically.  This type of capacitors utilized to set frequency of resonance in LC circuits.  To adjust the radio for impedance matching in antenna tuner devices.

Types Of Capacitors And Their Applications How to Know the Value of Capacitors?  Capacitors are the essential components of an electronic circuit without which the circuit cannot be completed.  Different types of capacitors like Electrolytic capacitor, Disc capacitor, Tantalum capacitor etc are used in circuits.  Electrolytic capacitors have value printed on its body so that its pins can be easily identified.  Usually the large pin is positive.

Types Of Capacitors And Their Applications How to Know the Value of Capacitors?  The black band present near the negative terminal indicates the polarity.  But in Disc capacitors, only a number is printed on its body.  It is very difficult to determine its value in PF, KPF, uF, n etc.  For some capacitors the value is printed in terms of uF, while in others a EIA code is used.

Types Of Capacitors And Their Applications Methods to Identify the Capacitor and to Calculate its Value 1.The number on the capacitor represents the capacitance value in Pico Farads. For example, 8 = 8PF 2. If the third number is zero, then the value is in P e.g. 100 = 100PF 3. For a 3 digit number, the third number represents the number of zeros after the second digit For example, 104 = 10 – 0000 PF 4. If the value is obtained in PF, it is easy to convert it into KPF or uF, PF / 1000 = KPF or n, PF / 10, = uF. For a capacitance value of 104 or in pF, it is 100KpF or n or 0.1uF.

Types Of Capacitors And Their Applications Conversion Formula  n x 1000 = PF PF/1000 = n PF/1,000,000 = uF uF x 1,000,000 = PF uF x 1,000,000/1000 = n n=1/1,000,000,000F uF = 1/ 1000,000 F.  The letter below the capacitance value determines the tolerance value.  473 = 473 K  For a 4 digit number, if the 4th digit is a zero, then the capacitance value is in pF.  E.g = 1500PF

Types Of Capacitors And Their Applications Conversion Formula  If the number is just a floating point decimal number, the capacitance value is in uF.  E.g. 0.1 = 0.1 uF  If an alphabet is given below the digits, it represents a decimal and the value is in KPF or n  E.g. 2K2 = 2.2 KPF  If the values are given with slashes, the first digit represents value in UF, second its tolerance and third its maximum voltage rating  E.g. 0.1/5/800 = 0.01 uF / 5 % / 800 Volt.

Types Of Capacitors And Their Applications Some Common Disc Capacitors Are

Types Of Capacitors And Their Applications Some Common Disc Capacitors Are  Without a Capacitor, the circuit design will not be complete since it has an active role in the functioning of a circuit  The Capacitor has two electrode plates inside separated by a dielectric material such as paper, mica.  What happens when the electrodes of the capacitor are connected to a power supply?  The capacitor charges to its full voltage and retains the charge.

Types Of Capacitors And Their Applications Some Common Disc Capacitors Are  The capacitor has the ability to store current which is measured in terms of Farads.  The capacitance of a capacitor depends on the area of its electrode plates and the distance between them.  Disc capacitors do not have polarity.  So that they can be connected either way round.

Types Of Capacitors And Their Applications Some Common Disc Capacitors Are  Disc capacitors are mainly used for coupling / decoupling the signals.  The Electrolytic capacitors on the other hand have polarity.

Types Of Capacitors And Their Applications Some Common Disc Capacitors Are  If the polarity of the capacitor changes, it will explode.  Electrolytic capacitors are mainly used as filters, buffers.  Each capacitor has its own capacitance which is expressed as the Charge in the capacitor divided by the Voltage.  When you use a capacitor in a circuit, some important parameters should be considered.

Types Of Capacitors And Their Applications Some Common Disc Capacitors Are  First is its Value. Select a proper value.  Either low or high value depending on the circuit design.  The value is printed on the body of most of the capacitors in uF or as EIA code.  In Color coded capacitors, the values are represented as color bands.  By using a capacitor color code chart; it is easy to identify the capacitor.

Types Of Capacitors And Their Applications Color Chart to Identify a Color Coded Capacitor  Resistors each band on the capacitor has a value.

Types Of Capacitors And Their Applications Color Chart to Identify a Color Coded Capacitor  The value of the First band is the First number in the color chart.color chart  The value of the Second band is the Second number in the color chart.  The Third band is the multiplier as in the case of a resistor.  Fourth band is the Tolerance of the capacitor.  The Fifth band is the body of the capacitor which represents the Working voltage of the capacitor.  The Red color represents 250 volts and Yellow represents 400 volts.

Types Of Capacitors And Their Applications Capacitor Tolerance and Working voltage  Tolerance and Working voltage are two important factors to be considered.  No capacitor has the rated capacitance and it may vary.  So use a good quality capacitor like Tantalum capacitor in sensitive circuits like oscillator circuits.  The working voltage of the electrolytic capacitor is printed on its body.

Types Of Capacitors And Their Applications Capacitor Tolerance and Working voltage  Leakage current is another problem in capacitors.  Some of the charge will leak, even if the capacitor is charging  This is verse in Timer circuits since the timing cycle depends on the charge/discharge time of the capacitor.  Low leakage Tantalum capacitors are available and use them in Timer circuits.

Types Of Capacitors And Their Applications Understanding the Reset Capacitor Function in Microcontroller  A Reset is used to start-up or to restart the AT80C51 microcontroller functionality.  A reset pin follows two conditions to start up the microcontroller. They are 1) Power supply must be in the specified range. 2) The reset pulse width duration must be at least two machine cycles.

Types Of Capacitors And Their Applications Understanding the Reset Capacitor Function in Microcontroller  The reset must be kept active until all two of the conditions are respected.  In this type of circuit, the capacitor and resistor arrangement from the supply is connected to reset pin no. 9.  While the supply switch is ON, the capacitor starts charging.  At this time, capacitor acts like a short circuit in the beginning.

Types Of Capacitors And Their Applications Understanding the Reset Capacitor Function in Microcontroller  When reset pin set to HIGH, the microcontroller goes to the power on state and after some time the charging stops.  When charging stops, the reset pin goes to ground because of the resistor.  The reset pin should go to high then go to low, then program starts from begging.

Types Of Capacitors And Their Applications Advantages  Long life, with little degradation over hundreds of thousands of cycles.  Low cost per cycle  Good reversibility  Very high rates of charge and discharge.  Extremely low internal resistance (ESR) and consequent high cycle efficiency (95% or more) and extremely low heating levels.  High output power.

Types Of Capacitors And Their Applications Disadvantages  The amount of energy stored per unit weight is considerably lower than that of an electrochemical battery.  As with any capacitor, the voltage varies with the energy stored.  Has the highest dielectric absorption of any type of capacitor.  Cells have low voltages – serial connections are needed to obtain higher voltages.  Voltage balancing is required if more than three capacitors are connected in series.  Linear discharge voltage prevents use of the full energy spectrum.

Types Of Capacitors And Their Applications Applications  Capacitors have applications in both electrical and electronics.electrical and electronics  They are used in filter applications, energy storage systems, motor starters and signal processing devices.  Capacitors are used for power factor correction.  Use of capacitors includes smoothing the ripples from AC in power supply, coupling and decoupling the signals, as buffers etc.

Types Of Capacitors And Their Applications Conclusion  The comparisons between the different types of capacitors are generally made with regards to the dielectric used between the plates. Some capacitors look like tubes, small capacitors are often constructed from ceramic materials and then dipped into an epoxy resin to seal them.different types of capacitors