Chapter 4Transients1.Solve first-order RC or RL circuits.2. Understand the concepts of transient response and steady-state response.3. Relate the transient response of first-order circuits to the time constant.4. Solve RLC circuits in dc steady-state conditions.TransientsThe time-varying currents and voltages resulting from the sudden application of sources, usually due to switching, are called transients. By writing circuit equations, we obtain integrodifferential equations.Discharge of a Capacitance through a ResistanceThe time interval = RC iscalled the time constant ofthe circuit.DC STEADY STATEThe steps in determining the forced response for RLC circuits with dc sources are:1. Replace capacitances with open circuits.2. Replace inductances with short circuits.3. Solve the remaining circuit.Solve for the steady-state values of the labeled currents and voltages for the circuits.RL CIRCUITSThe steps involved in solving simple circuits containing dc sources, resistances, and one energy-storage element (inductance or capacitance) are:1. Apply Kirchhoffs current and voltage laws to write the circuit equation.2. If the equation contains integrals, differentiate each term in the equation to produce a pure differential equation.3. Assume a solution of the form K1 + K2est.4. Substitute the solution into the differential equation to determine the values of K1 and s . (Alternatively, we can determine K1 by solving the circuit in steady state as discussed in Section 4.2.)5. Use the initial conditions to determine the value of K2.6. Write the final solution.RL Transient AnalysisTime constant isP4.4 P4.5 P4.6 P4.8