Capacitor is an electronic device for storing charge. The simplest type of capacitor: parallel plate capacitor shown as figure; two conducting components (plats) with area S separated by distance d and charged with charge, +q and -q.
In electronic circuit, capacitor is shown like this![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjZtJhbflaIbrslG3rKXV8yVpDorZkBhB5XlPCXAPPMw7Q8Zm_beb6HnO2JHlwjg9fVSVDwRt781w_OAC5GiisXijjVm4x06xoKdnxG4nYpPQ470HpBcdbF05cK2ZJ12WcZsUUMswFz_Pw/s1600/Screenshot.png)
One way to visualize the action of a capacitor is to imagine it as a water tower hooked to a pipe. A water tower "stores" water pressure -- when the water system pumps produce more water than a town needs, the excess is stored in the water tower. Then, at times of high demand, the excess water flows out of the tower to keep the pressure up. A capacitor stores electrons in the same way, and can then release them later.
- Charging
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgGbd1k3n6fa7aAIU8jb8tILt0jltgHEvnIMPpYL8gjl6v7AXtYHnr5dmJBnOWKc6NzB3SlxGrYIDSU4rhzhZ1J8D39KsdQebIL0Nv1FVLOdedJd2YHQ21k-XgbboNKqGefe4HRk0kATyQ/s1600/charging.png)
When connected to battery, Plate attached to positive pole of battery will loss electrons. Plate attached to negative pole of battery will receive electrons. Capacitor will have the same voltage as the battery.
- Discharging
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiNKYgqGpEhsEE2uVjFEViISoaElbkkz5TNU0Jpwr5U90GPOkodCWQJ-pM6kQ9P9t8tz7kVGawCYY6rx1LPyaFBW1kiMPXlvAiKuV1AknZhvCqPGredMtYqcWwp_P9QIC2ltCdW5KJ_ImE/s1600/Screenshot-1.png)
When a bulb is hooked with the capacitor and the battery is replaced by wire, current will flow from one plat of the capacitor to the other and light the bulb until the capacitor completely discharge.
Capacitor has the same function as battery, but with very different way of work. The difference between a capacitor and a battery is that a capacitor can dump its entire charge in a tiny fraction of a second, where a battery would take minutes to completely discharge itself.
The use of capacitor in connection with other electronic devices:
-Reduces voltage fluctuation in electronic power supply
-A capacitor allows pulse signals to flow
-Made up an oscillator circuit if associated with inductive component
-Filtering specific frequency
-Provide electronic time delay