1. Transient Analysis
Transient: transition region between two steady state, e.g. edges of square wave.
Very important in digital circuit: delay.

2. Motivation

3. The Capacitor Effect

4. Charging and discharging a capacitor
Battery ε C
This is true only for thus particular circuit! For complicate circuit, use Thevenin

5. Charging a Capacitor t t i v(t) e e/R 0.63 e/R 0.63e t=RC=t t=RC=t
Time constant (t): time needs to charge a capacitor to 63% of its full charge.
The larger the RC, the longer it takes to charge a capacitor.
The larger the R value, the smaller the current is in the circuit.
The larger the C value, the more the charge the capacitor can hold

6. Discharging a Capacitore
Vc=e
++++
---- e
i=0
Vc=e
++++
---- t
vC(t) e

7. Example
Remember Demo
determined by RC const.

8. Concept Check: RC circuit
Charging Capacitors
(a) (b) (c)
Which configuration has the largest final charge on the capacitor?
Which capacitor charges faster?
Answers: (1) same; (2) (b)