1、复数的代数式:F=a+jbj=√-1 2、复数的矢量表示 3、复数的三角式:

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

sinusoidal current or voltage at a given frequency is characterized by only two parameters an amplitude and a phase angle. The complex representation of the voltage or current is also characterized by these same two parameters

The effective value of any periodic current is equal to the value of the direct current which flowing through a resistance R, delivers the same power to r as periodic current does

In either case, leading or lagging, we say that sinusoids are out of phase () if phase angles equal they are said to be in phase(同相)

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

The over-damped response---- i()= A,+A, The critically-damped response-- i(t) =e (At+A2) The under-damped- response---it)e-(b1 cos+2 sino)

例1求以下函数的象函数 (1)单位阶跃函数 (2)单位冲击函数 (3)指数函数

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)

3.1 电容式传感器的原理与结构 3.2 电容式传感器的测量电路 3.3 电容式传感器的应用