16-02-2013, 10:28 AM
ENERGY STORED BY A CAPACITOR
[attachment=51133]
Introduction
Two important passive linear circuit elements:
Capacitor
Inductor
Capacitor and inductor can store energy only and they can neither generate nor dissipate energy.
Capacitors
A capacitor has two parallel plates separated by an insulating material
A capacitor stores an electrical charge between the two plates
The unit of capacitance is Farads (F)
Capacitance values are normally smaller, such as µF, nF or pF
Storing a charge between the plates
Electrons on the left plate are attracted toward the positive terminal of the voltage source
This leaves an excess of positively charged holes
The electrons are pushed toward the right plate
Excess electrons leave a negative charge
Types of Capacitors
The dielectric material determines the type of capacitor
Common types of capacitors are:
Mica
Ceramic
Plastic film
Capacitors
Some capacitors are polarised, they can only be connected one way around
Electrolytic capacitors are polarised
Variable capacitors are used in communication equipment, radios, televisions and VCRs
They can be adjusted by consumers by tuning controls
Trimmers are internal adjusted capacitors that a consumer cannot adjust
[attachment=51133]
Introduction
Two important passive linear circuit elements:
Capacitor
Inductor
Capacitor and inductor can store energy only and they can neither generate nor dissipate energy.
Capacitors
A capacitor has two parallel plates separated by an insulating material
A capacitor stores an electrical charge between the two plates
The unit of capacitance is Farads (F)
Capacitance values are normally smaller, such as µF, nF or pF
Storing a charge between the plates
Electrons on the left plate are attracted toward the positive terminal of the voltage source
This leaves an excess of positively charged holes
The electrons are pushed toward the right plate
Excess electrons leave a negative charge
Types of Capacitors
The dielectric material determines the type of capacitor
Common types of capacitors are:
Mica
Ceramic
Plastic film
Capacitors
Some capacitors are polarised, they can only be connected one way around
Electrolytic capacitors are polarised
Variable capacitors are used in communication equipment, radios, televisions and VCRs
They can be adjusted by consumers by tuning controls
Trimmers are internal adjusted capacitors that a consumer cannot adjust