Capacitors are one of a few common, passive, electrical components used in a variety of different ways. At the most basic level the purpose of capacitors is to store electric charge, but it is also used in various other applications. To know what other applications capacitors have learn more from www.directics.com/electronic-components-list/.
Construction: The most basic design of a capacitor consists of two metal plates, each connected to it’s own electrode and separated by a non-conductive material called a dielectric.
Factors that determine the charge a capacitor can hold:
The charge a capacitor can hold is limited by three factors.
1. The area of the two metal plates used: A larger area can store a bigger charge.
2. The type of dielectric: The ability of the dielectric to isolate the two plates from each other limits the charge that can be held on the metal plates. If the dielectric is a good insulator no charge can leak across it and a larger charge can be held.
3. The distance between the plates: The smaller the distance between the plates the smaller the charge that can be held.
Basic working of the capacitor:When a capacitor is connected to a DC power source like a cell, electrons move from the negative terminal of the cell towards the plate to which it is connected.At the same time the positive terminal of the cell attracts any electrons from the plate to which it is connected.
This creates a potential difference between the two plates of the capacitor, since one plate has an abundance of electrons (negative charge) and the other has an lack of electrons (positive charge). This will continue until the voltage drop between the two plates is equal to the supply voltage of the cell.
If the cell were to be disconnected, the capacitor will hold it’s charge until it is connected to another circuit or such time that the charge is neutralized through leakage current across the dielectric.
It is useful to note that in an alternating current circuit, a capacitor will act as a short circuit at high frequencies since the change in polarity of the supply voltage is quicker than the charging time of the capacitor.
Types of capacitors: There are a variety of capacitors on the market, each designed for a very specific use.They range from tiny ceramic, axial or electrolytic capacitors used in electronic circuits, to large capacitors use in strobe lights, electric motors and electric fence energizers.
Uses: Capacitors can simply be used to store an electric charge for a limited
Time: Capacitors are used in tuned electric circuits like FM-senders and
Receivers: Capacitors can be used in filtering, smoothing and rectifying circuits.
Capacitors are used as protective devices in electronics to prevent DC feedback in a variety of amplifier circuits. Capacitors are used in AC power installations to improve the power factor and make the electricity usage more efficient. It does this by causing a phase shift between the current and voltage which opposes the effect caused by mostly inductive devices used in houses and industries.
What is a capacitor then?
It is a very simple electronic component that uses the principles of electrostatics to store and release charge in a controlled manner.