《电路》（英文版）7-6 Phasor relationships for、and R:

A real, an imaginary, or a complex forcing function will produce a real, an imaginary, or complex response, respectively. Instead of applying a real forcing function to obtain the desired real response, we apply a complex forcing function whose real part is the given real forcing function; we obtain a complex response whose real part is the desired real response

The forced response The steady state responseThe(t) has been switched into the circuit at some remote U.=V. cos ot time in the past, and the natural response has died-out completely. The forced response(steady state response)must satisfy the differential equation

The complete response is written as the sum of the forced and the natural response, and the initial conditions are then determined and applied to the complete response to find the values of the constants

A1, A,----two arbitrary constants S S2----real numbers or conjugate complex Since the s,t and s,t must be dimensionless, S,, S2----(1/s)

The complete response of any RC circuit may also be obtained as the sum of the natural and the forced response

Let us assume a solution i(t=Ae, where a and S, are constant to be determined

4-5 Simple capacitor-OP-AMP-circuits Integrator op-amp circuit (Integrator):

Two circuits are dual if the mesh equations that characterize one of them have the same mathematical form as nodal equations that characterize the other

A current-carrying conductor produced a magnetic field (1800). A changing magnetic field could induce a voltage in a neighboring circuit(1820)