Function Of Capacitor In an Electronic Circuit = A capacitor (originally known as a condenser) is a passive two-terminal electrical component used to store energy electrostatically in an electric field. The forms of practical capacitors vary widely, but all contain at least two electrical conductors separated by a dielectric (insulator); for example, one common construction consists of metal foils separated by a thin layer of insulating film. Capacitors are widely used as parts of electrical circuits in many common electrical devices.
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When there is a potential difference across the conductors, an electric field develops across the dielectric, causing positive charge to collect on one plate and negative charge on the other plate. Energy is stored in the electrostatic field. An ideal capacitor is characterized by a single constant value, capacitance. This is the ratio of the electric charge on each conductor to the potential difference between them. The SI unit of capacitance is the farad, which is equal to one coulomb per volt.
The capacitance is greatest when there is a narrow separation between large areas of conductor, hence capacitor conductors are often called plates, referring to an early means of construction. In practice, the dielectric between the plates passes a small amount of leakage current and also has an electric field strength limit, the breakdown voltage. The conductors and leads introduce an undesired inductance and resistance.
Capacitors are widely used in electronic circuits for blocking direct current while allowing alternating current to pass. In analog filter networks, they smooth the output of power supplies. In resonant circuits they tune radios to particular frequencies. In electric power transmission systems they stabilize voltage and power flow.
A capacitor is a circuit element that can store electric charge. They can be used in a variety of ways. One common use is to pass higher frequencies. This can be either to remove those frequencies, or to extract a signal from a low-frequency or DC current. In combination with inductors, capacitors create oscillating circuits, used for purposes including tone generation and radio tuning. Capacitors are also used to store electricity to fill in for momentary fluctuations in a DC supply. Large ones are used on high-power car audio amplifiers to provide extra peak power and keep the loud bass notes from making the headlights flicker.
The capacitor's greatest limitations are that it can only store a limited voltage (so make sure when you use one the voltage rating is high enough for your circuit). Arguably one of its benefits is it can release a whole lot of charge at a rapid rate.
They are made with a preferably thin non-conducting material (dielectric) between two metal conductors (plates) which will fail under high voltage. This dielectric is where the energy is actually stored (unlike batteries which typically use a chemical reaction...and thus a more sustained voltage as current is drained).
A capacitor has many and different uses :
- In a power supply, it acts to filter the output so there is little ripple.
- In an amplifier, it can be used to block DC and allow AC to pass.
- In general, it acts as a filter, blocking lower frequencies and passing higher ones.
- In power circuits it can correct the power factor so that the current and voltage are in phase, or more so.
- In motors it shifts the phase so that the motor will run.
- It's used to store charge in applications like a flash on a camera.
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