Capacitors

THEORY:

Capacitor are used in a electrical circuit to store electrostatic charge. They are in some way like a battery but capacitors can not create new electrons that enter through the negative plate of the capacitor. A capacitor is made of two metal plates that are separated by a non-conducting insulator. There are many types of capacitors and all vary in how much it can hold/store. These components are used often for dampening voltage spikes and to time electronic . Capacitor store as much energy as is put into it e.g 12v battery, capacitor will store 12v until the battery is replaced with a wire which will then make a complete circuit will then cause the capacitor to discharge the electrostatic charge. If there were a bulb in the circuit, it would turn on but as the stored charge is used by the bulb it would make the bulb at first shine bright and then slowly get dimmer and finally go out.

TEST:


One test is to:

12v power supply, 1x 100ohm resistor, 1x 300uf capacitor, 1x N/O switch.

When circuit was made, it was in series which shows that voltage/ampere will flow through the circuit, through the resistor where it will regulate the voltage to the capacitor, were then voltage (electrostatic charge) is stored with switch parallel to capacitor and then circuit runs back to earth.

With switch on, the capacitor is able to get charged and store voltage. If a bulb was in the circuit, it would be very bright cause the power supply is good. As soon as switch is off, the bulb will remain on until all of the electrostatic charge is used making the bulb go dimmer and depending on which capacitor is used eventually going out.

A 300uf capacitor when fully charged takes about 90 seconds after switch/bridge wire is off,  before the voltage out of capacitor starts to even out which shows that the electrostatic charge is now low within the capacitor and at 180 second is now close to being empty.


REFLECTION:


If had a circuit and I needed a certain component in my circuit to be on after I have turned it off then I would put a capacitor in the circuit that would store the charge that I'd need for it. So capacitors are a important part of a circuit for its ability it store and disperse electrostatic charge.