What is a Capacitor
Capacitors are electric components that can be used for the purpose of storing charges. A simple capacitor consists of two conducting plates that are separated by a dielectric. Thus, any electric circuit that requires a steady flow of eclectic charges can make use of capacitor to ensure that the output from the capacitor is smooth DC. The storing capacity of a capacitor is termed as ‘capacitance’ and the unit used to express capacitance is ‘Farad’. The capacitance of a capacitor is a measure of the amount of charge stored between two conducting plates at a certain potential difference; separated by a dielectric. There are various types of capacitors based on the kind of dielectric that is made use and the value of capacitance.
The main classification of capacitors can be done under two heads, namely electrolytic capacitors and non electrolytic capacitors. The simple explanation for the difference between the two can be provided as follows. An electrolytic capacitor is polarized and has fixed positive and negative terminals. Thus, while placing it in a circuit, it is important that the positive terminal is placed in the positive side of the circuit and vice versa. On the other hand, a non electrolytic capacitor can be placed without such restrictions. Generally, the non electrolytic capacitors have low capacitance value as compared to the electrolytic capacitors.
When a capacitor is placed in an electric circuit, it charges slowly and stores the electric charges. When the power connection is removed, the capacitor still has some charges stored in it and discharging of the capacitor takes place. Thus, this property of the capacitor makes it an important component to be used in various electric circuits like the timer. The capacitor resembles a battery in some of its properties and owing to this property of storing charges; capacitors are made use in the place of battery when an old battery has to be replaced by a new one.
In tuning circuits, where the operation is limited to a particular frequency, capacitors are used along with inductors. These kinds of circuits are normally seen in radio receivers. Filter circuits too make use of capacitors to ensure that the unwanted noise signals are stopped from interfering with the original signal. A capacitor can take in fluctuating DC and output smooth DC.
It is to be noted that though capacitors are passive electronic components, they store charges for a relatively large period of time. Thus, care needs to be taken while handling the capacitors with high capacitance to ensure that chances of electric shocks are nullified. Usually, in these kinds of capacitors, both terminals are shorted to avoid hazards of any kind.