2. Capacitors What They Are, How They Work, and Stuff Anthony Bisceglia

3. What is a Capacitor It is a basic device of a circuit used to store charge. It is constructed by placing two conductors plates which are separated by a dielectric A common conductor material is Aluminum Common dielectrics are air, glass, porcelain, paper, or Teflon

4. Original Capacitors The Leyden Jar A first breakthrough in storing charge. Pieter van Musschenbroek, a Dutch professor at the University of Leyden

5. Parts to a Capacitor The Conductor plates are what attract the charge. The dielectric is located between the plates The electric field is through the dielectric Capacitance is a measure of a capacitor’s ability to store Charge, measured in the units Farads (F)

6. How to Determine Charge Q=CV Q=Charge, Coulombs (C) V=Voltage, Volts (V) Q=VC, which becomes obvious that charge is directly proportional to the voltage applied and to the capacitance.

7. How to determine Capacitance of a Capacitor C=Є A/d C= Capacitance, farads(F) Є=permittivity, (F/m) A=area, (m 2 ) d=distance, (m) Noting the equation it shows that capacitance is directly proportional to Є and A. and inversely proportional to d.

8. Permittivity Permittivity is equal to the Dielectric Constant by the Relative Permittivity of the dielectric being used. Є=Є о Є r Є о = 8.85x 10 -12 F/m

9. ЄrЄr Relative Permittivity Table

10. Comparison Capacitor with air as a dielectric. C= Є о Є r A/d =(1 x 8.85x 10 -12 F/m x 1m 2 )/1m =8.85 picofarads Capacitor with paper as a dielectric C= Є о Є r A/d =(2.5 x 8.85x 10 -12 F/m x 1m 2 )/1m = 22.1 picofarads In conclusion, this comparison shows that without changing the dimensions of the capacitor the capacitance can be increased by changing the dielectric.

11. Use for Capacitors Capacitors main trait is their ability to charge and discharge quickly. Capacitors are used in the flash of a camera. Its bright surge of light comes from a capacitor’s discharge.

12. Works Cited Boylestad, Robert L. Introductory Circuit Analysis Eleventh Edition, NJ: Pearson Education Inc, 2007 Brain, Marshall. How Stuff Works, How Capacitors Work. November 29, 2009. http://electronics.howstuffworks.com/cap acitor.htm http://electronics.howstuffworks.com/cap