01-08-2012, 11:44 AM
Capacitors
capacitors.ppt (Size: 579 KB / Downloads: 32)
What is a capacitor?
Electronic component
Two conducting surfaces separated by an insulating material
Stores charge
Uses
Time delays
Filters
Tuned circuits
Defining capacitance
Good’ capacitors store a lot of charge…
…when only a small voltage is applied
Capacitance is charge stored per volt
Capacitance is measured in farads F
Big unit so nF, mF and F are used
When t equals tau during discharge
At t = tau the capacitor has fallen to 37% of its original value.
By a similar analysis tau can be considered to be the time taken for the capacitor to reach 63% of full charge.
capacitors.ppt (Size: 579 KB / Downloads: 32)
What is a capacitor?
Electronic component
Two conducting surfaces separated by an insulating material
Stores charge
Uses
Time delays
Filters
Tuned circuits
Defining capacitance
Good’ capacitors store a lot of charge…
…when only a small voltage is applied
Capacitance is charge stored per volt
Capacitance is measured in farads F
Big unit so nF, mF and F are used
When t equals tau during discharge
At t = tau the capacitor has fallen to 37% of its original value.
By a similar analysis tau can be considered to be the time taken for the capacitor to reach 63% of full charge.