Thursday, 24 March 2011

Capacitors

25/3/2011

The first exercise i did, i had to calculate and measure the charge time of a range of different size capacitors and using different size resistors aswell.





 while doing this experiment i found out that the bigger the resistor in the circuit, the longer it takes for the capacitor to charge up. this happens because the more resistance in the circuit, the less amperage aloud to flow though the circuit which makes the capacitor charge up slower.
when i introduced a bigger capacitor, i found it took  longer to charge up because it is a larger space to fill, therefore it takes longer to fill up.
e.g. a bigger bucket will take longer to fill with water than a small bucket.

to calculate the the time you use the formula. (capacitor x resistance x 5)

1 micro farrad = 100 exp-6 x 1000 ohms x 5 = 0.5 secs

to measure the time it took to charge i used a wire on one side of my capacitor and a wire on the other side. when i connected the two wires my capacitor started charging and when i disconnected the wires my capacitor discharged.
i measured to see if my calculations were correct by attaching a oscilloscope to each side of the capacitor and gathered my data:

Each division on the y axis of the graph is 2 volts and each division of the x axis is 100 milli seconds

I recorded my first 3 graphs




This is my 100 micro farrad capacitor with my 1000 ohms resistor.

This shows it took 600 milli seconds to charge up the capacitor.













This is the 330 micro farrad capacitor with the 1000 ohm resistor




This tells us that is took around 800 milli seconds to fully charge the capacitor.





this is the 100 micro farrad capacitor with a 0.1 killer ohm resistor



In this picture you can see that the capacitor was fully charged within 100 milli seconds.










As you can see, a capacitor has 5 different charging stages.
the first stage, the capacitor gets filled up the most up to 63%.
The next stage is 85% then 95%, 98% and 99%.

 note:    the capacitor never fully gets filled 100%




Reference:

I got this image from: www.ehobbycorner.com
I also got the picture of the capacitor from
ca7science.wikispaces.com

1 comment:

  1. Can you please add the calculation for all the capacitors and relate then to your pictures,also can you explain why their is a slope on your pattern

    ReplyDelete