19 - Impedance

INTRO: Today we focused on a familiar concept of Impedance. Impedance (Z) is the ratio of the phasor voltage to the phasor current. In more familiar terms, the impedance of a circuit is the circuits resistance to alternating current. Impedance of a circuit can alternatively be calculated by summing the resistance, capacitance, and inductance in a circuit.


Below is a simple circuit with a voltage source, and impedances. Ignore the circuit values in non-time domain values,since it is unimportant for now.



 LAB: IMPEDANCE
 In this lab we will build a circuit and calculate the impedance of three elements; a resistor, capacitor, and inductor. We will then check our experimental values against our calculated ones.

 Below we drew and calculated the impedance values for our three circuits. The circuits are a normal resistive circuit, a RL circuit, and then a RC circuit. As seen as the pictures below, we list the calculated values for the impedance.


Resistive Circuit and accompanying graph at 1k frequency



 RC circuit and accompanying graph at 1k frequency



 RL and accompanying graph at 1k frequency



In the chart below we charted the values from all three of our circuits. Although just one graph per circuit is listed in the situations above, we ran each circuit three times at 1,5,10 khz. The experimental values were relatively close to our calculated values.