1. Fluid flow analogy

3. Power and energy in an inductor

7. Capacitor v-i equation

10. Capacitor Power equation

11. Capacitor : power and energy

13. The self- and mutually induced voltages

17. 7-1. The natural response of an RL circuit Independent current source I S. The switch has been closed for a “long time”. L di/dt = 0 at t <0 (before the release of stored energy) ; the inductor appears a s a short circuit. No current in R 0 and R ; all the current appears in L branch.Finding v(t) and i(t) for t>=0.

18. Expressions for the current LR Circuits Equations

19. RL circuits (cont’d)

22. Time constant

23. Time constant (1% of the initial value at five time constants) -less than 5 constants : the transient response - exceeds 5 constants : steady- state response

24. Time constant (cont’d) Determination of time constant Equations (cont’d)

25. Calculating the response of RL circuit

26. 7-2 The natural response of an RC circuit An RC circuit is analogous to an RL circuit The switch has been in the position for a long time such that all the elements in the circuit reach a steady-state condition. A source voltage exists between the terminals. Circuit after switching is shown in Fig. 7-11.

27. Expression for the voltage Circuit consisting of R, C and Vg