RC Circuits

This java applet try to show the transient behavior that occurs when the capacitor is being charged and discharged.

1. You will find a 10 Volt Voltage source,
Click within the green area and drag the mouse up/down
to change its value.
2. A 100k ohms resistor and a 100uF in series¡C(k=103 , u=10-6 )

3. There is a switch to control the flow path of the circuit.

Click near the (Black) switch to change between
horizontal position: charging
and vertical position: discharging.
If you click the mouse button twice,
the timing record t will be reset to zero.
You can get Vc-t plot similar to this (click me).
4. Press Start to start the animation,
The program will show the voltage of capacitor(Vc) and resistor.
It also draw Vc-t(ime) curve.

5. You can change the switch at any time.

6. If the mouse is inside the Vc-t plot area,
Its values corresponse to mouse position will be displayed.
If you drag the mouse, It will show relative value.

7. The animation is suspended when you press the mouse button.
If you click with left mosue button,
animation continues when you release the mouse button.
If you click with the right mouse button,
you will need to press the mouse again to resume.

From Kirchoff's lope Rule
During the changing process: Vo = VR + Vc
= I R + ¡ìI dt/C
During the discharging process Vc = -VR
= ¡ìI dt/C = -I R
How to do the calculatation?
If the time interval dt is very small,
integral become summation.
During the charging process:

1. Find current I => I = (Vo - Vc )/ R

2. Then calculate new Vc => Vc = Vc + I *dt/C

3. calculate VR = I * R

You should be able to find out the rest.

Check out another RC circuit simulation

Your suggestions are highly appreciated. E-mail ¡G hwang@phy03.phy.ntnu.edu.tw

`Author¡GFu-Kwun Hwang, Dept. of physics, National Taiwan Normal University`
```Last modified :  <!--hide script from old browsers
document.write(document.lastModified);
// end hiding -->
```