Electric circuit analysis 1 series RC circuit explanation presentation

Electric circuit analysis, resistor capacitor circuit presentation

1. LAB#11 RC CIRCUITS Done by: Bilal Hassan Hashir Muzafar

2. What is a RC circuit Any circuit that contains a resistor connected with a capacitor is known as an RC circuit. If more than one resistor or capacitor is connected, we will have to combine them and form the standard RC circuit as shown below

3. Natural response of RC circuits: When the switch is closed, current starts flowing through the circuit and the capacitor starts charging. After a long time the capacitor is full charged and it becomes an open circuit. When the switch is closed it starts discharging all the stored energy.

4. Charging equation and its graph Vc: voltage of capacitor Vs: source voltage RC: time constant

5. Discharging equation and its graph V(t): voltage of capacitor V(0): initial voltage of capacitor 𝜏 : time constant 𝜏 = R x C

6. When t<0 the switch is at position A and the capacitor is open. Current doesn’t flow in the circuit so applying kvl we get: -40 + 0 + V(0)=0 so v(0) =40 V

7. When t<0 the switch is at position B and the capacitor starts discharging Req=2k ohm 𝜏 = R x C so 𝜏 = 2000 x 10x10^-6 = 20mS V(t)=V(0)e^-t/ 𝜏 So V(t)=40e^-t/0.02 2k Ω 10 μ F

8. time V(t) % V(t) 1 𝜏 36.8% 14.7 V 2 𝜏 13.5% 5.4 V 3 𝜏 4.97% 1.99 V 4 𝜏 1.83% 0.73 V 5 𝜏 0.67% 0.26 V