Sunday, August 6, 2017

Types of Capacitor - Different Types of capacitor - Capacitor Types




A capacitor formerly known as a condenser, and prior to that known as a permittor  is a passive two-terminal electrical component that stores electric energy in an electric field. The forms, styles, and materials of practical capacitors vary widely, but all contain at least two electrical conductors separated by an insulating layer. Capacitors are widely used as parts of electrical circuits in many common electrical devices.


Video Source By- Learning Engineering

Electronic capacitors are one of the most widely used forms of electronics components. However there are many different types of capacitor including electrolytic, ceramic, tantalum, plastic, sliver mica, and many more. Each capacitor type has its own advantages and disadvantages can be used in different applications.
The choice of the correct capacitor type is of great importance because it can have a major impact on any circuit. The differences between the different types of capacitor can mean that the circuit may not work correctly if the correct type of capacitor is not used.






The ceramic capacitor is a type of capacitor that is used in many applications from audio to RF. Values range from a few picofarads to around 0.1 microfarads. Ceramic capacitor types are by far the most commonly used type of capacitor being cheap and reliable and their loss factor is particularly low although this is dependent on the exact dielectric in use. In view of their constructional properties, these capacitors are widely used both in leaded and surface mount formats. 


 Electrolytic capacitors are a type of capacitor that is polarized. They are able to offer high capacitance values - typically above 1μF, and are most widely used for low frequency applications - power supplies, decoupling and audio coupling applications as they have a frequency limit if around 100 kHz. 


 Like electrolytic capacitors, tantalum capacitors are also polarised and offer a very high capacitance level for their volume. However this type of capacitor is very intolerant of being reverse biased, often exploding when placed under stress. This type of capacitor must also not be subject to high ripple currents or voltages above their working voltage. They are available in both leaded and surface mount formats. 

  
Silver mica capacitors are not as widely used these days, but they still offer very high levels of stability, low loss and accuracy where space is not an issue. They are primarily used for RF applications and and they are limited to maximum values of 1000 pF or so. 


 Polystyrene capacitors are a relatively cheap form of capacitor but offer a close tolerance capacitor where needed. They are tubular in shape resulting from the fact that the plate / dielectric sandwich is rolled together, but this adds inductance limiting their frequency response to a few hundred kHz. They are generally only available as leaded electronics components.


 Polyester film capacitors are used where cost is a consideration as they do not offer a high tolerance. Many polyester film capacitors have a tolerance of 5% or 10%, which is adequate for many applications. They are generally only available as leaded electronics components. 


This type of capacitor is a essentially a form of polyester film capacitor where the polyester films themselves are metalized. The advantage of using this process is that because their electrodes are thin, the overall capacitor can be contained within a relatively small package. The metalized polyester film capacitors are generally only available as leaded electronics components.


 As the name implies, this capacitor type uses glass as the dielectric. Although expensive, these capacitors offer very high levels or performance in terms of extremely low loss, high RF current capability, no piezo-electric noise and other features making them ideal for many performance RF applications. 


Also known as a super capacitor or ultra capacitor, as the name implies these capacitors have very large values of capacitance, of up to several thousand Farads. They find uses for providing a memory hold-up supply and also within automotive applications.