Electrical Circuits and Electronics课件（华南理工）Lecture 16.pptVIP

Chapter 4 Transients Aim Solve first-order RC or RL circuits; Understand the concepts of transient response and steady-state response; Relate the transient response of first-order circuit to the time constant; Solve RLC circuit in DC steady-state conditions. Transients Time-varying currents and voltages resulting from the sudden application of source, usually due to switching, are called transients. Lecture 16 First-Order RC Circuits Discharge of a Capacitance through a Resistance Prior to , the capacitor is charged to an initial voltage . At , the switch closes and current flow through the resistor, discharging the capacitor. Discharge of a Capacitance through a Resistance Applying KCL: The solution is the form of： Discharge of a Capacitance through a Resistance Solving the equation, we have: Discharge of a Capacitance through a Resistance Solving the equation, we have: Discharge of a Capacitance through a Resistance The voltage across the capacitor must be continuos: The solution for the voltage is: Time interval Time constant: In one time constant the voltage decays by the factor Charge of a Capacitance from a DC Source through a Resistance The initial voltage across the capacitor before the switch closes: . Charge of a Capacitance from a DC Source through a Resistance Charge of a Capacitance from a DC Source through a Resistance Charge of a Capacitance from a DC Source through a Resistance Response Transient response: the response caused by the sudden application on the circuit; Steady-state response (forced response): The response caused by steady source. Electrical Circuits and Electronics School of Electric Power Electrical Circuits and Electronics School of Electric Power Electrical Circuits and Electronics School of Electric Power Electrical Circuit and Electronics School of Electric Power Electrical Circuit and Electronics School of Electric Power Electrical Circuit and Electronics School of Electric Po