Impedance Networks

The concept of impedance is central in classical electrical engineering. The simplest case is Ohm's Law for a resistor $R$ :

$$V(t) \eqsp R\, I(t)$$

where

$V(t)$ denotes the voltage across the resistor at time $t$

$I(t)$ is the current through the resistor

Impedance is the resistance $R$

For the corresponding mechanical element, the dashpot, Ohm's law becomes

$$f(t) \eqsp \mu\, v(t)$$

• $f(t)$ is the force across the dashpot at time $t$
• $v(t)$ is its compression velocity
• Dashpot impedance value $\mu$ is a mechanical resistance
• Dashpots and resistors are always real, positive impedances